45. Diagnosis /Indices – Radiographic Interpretation

Classical Periodontal Literature Review

Quick Search Terms

Study Questions:

  1. Are radiographs an accurate method of diagnosing periodontal disease?
  2. What alveolar crest level represents bone loss on a bitewing radiograph?
  3. Are digital radiographs equivalent to conventional radiographs in revealing bone loss?
  4. Are panoramic radiographs ever of value in periodontics?
  5. When should cone beam computed tomography (CBCT) be used?
  6. What if the significance of the lamina dura?
  7. Can radiographs be used to detect progression of periodontitis?
  8. Are radiographs an accurate way to assess healing after periodontal surgery?
  9. Do newer radiographic techniques improve the usefulness of radiographs?
  10. How do radiographic measurements compare to clinical examination measurements?
  11. How do the various radiographic techniques compare?

 

Radiograph accuracy

  1. Hardekopf J, et al. The “furcation arrow” – A reliable radiographic image? J Periodontol. 58:258 – 261, 1986.
  2. Deas DE, Moritz A., Mealey B et al: Clinical reliability of the furcation arrow as a diagnositc marker. J Periodontol 2006;77;1436-1441
  3. Ortman L, McHenry K, Hausmann E: Relationship between alveolar bone measured by 1251 absorptiometry with abalsysis of standardized radiographs: 2. Bjorn technique: J Periodntol 1982;53:311-314
  4. Buchanan SA, et al: Radiographic detection of dental calculus. J Periodontol. 58:747-751, 1987.

Bitewing radiographs

  1. Hausman E., Allen K., Clerehugh V. What alveolar crest level on a bite wing radiograph represents bone loss? J Periodontol 1991;62;570-572.
  2. Ritchey B, Orban B. The crests of the interdental alveolar septa. J Periodontol 1953;24:75-87.

Digital radiographs vs conventional radiographs

  1. Khocht A, Janal M, Harasty L, Chang K: Comparison of direct digital and conventioanl intraoral radiographs in detecting alveolar bone loss. J Am Dent Assoc 2003;134;1468-1475
  2. Bruder G, Casale J, Goren, A, Friedman S; Alteration of computer dental radiography images J Endod 1999;25;275-276

Panoramic radiographs

  1. Akesson. Comparison of panoramic and intraoral radiography and pocket probing for the measurement of the marginal bone level.” J Clin Periodontol 1992; 19: 326-332
  2. Kasaj A, Vasiliu Ch, Willershausen B. Assessment of alveolar bone loss and angular bony defects on panoramic radiographs. Eur J Med Res. 2008 Jan 23;13(1):26-30.
  3. Persson RE, Tzannetou S, Feloutzis AG, Brägger U, Persson GR, Lang NP. Comparison between panoramic and intra-oral radiographs for the assessment of alveolar bone levels in a periodontal maintenance population. J Clin Periodontol. 2003 Sep;30(9):833-9.

Cone beam computed tomography (CBCT).

  1. Walter C. Accuracy of three-dimensional imaging in assessing maxillary molar furcation involvement. J Clin Periodontol. 2010 May;37(5):436-41
  2. Walter C. Does three-dimensional imaging offer a financial benefit for treating maxillary molars with furcation involvement? A pilot clinical case series. Clin Oral Implants Res 2012;23:351-358.
  3. Grimard BA Comparison of clinical, periapical radiograph, and cone-beam volume tomography measurement techniques for assessing bone level changes following regenerative periodontal therapy. J Periodontol 2009;80:48-55
  4. The American Dental Association Council on Scientific Affairs. The use of cone beam computed tomography in dentistry: An advisory statement from the American Dental Association Council on Scientific Affairs. J Am Dent Assoc 2012;143;899-902
  5. MischKA, Yi ES, Sarment DP: Accuracy of cone beam computed tomography for periodontal defect measurements.. J Periodontol. 2006 Jul;77(7):1261-6.
  6. VandenbergheB, Jacobs R, Yang J. Detection of periodontal bone loss using digital intraoral and cone beam computed tomography images: an in vitro assessment of bony and/or infrabony defects. Dentomaxillofac Radiol. 2008 Jul;37(5):252-60.

The lamina dura

  1. Van der Linden L, Van Aken J. The periodontal ligament in the roentgenogram. J Periodontol 1970;41:243-248.
  2. Rams (1994). Utility of radiographic crestal lamina dura for predicting periodontitis disease activity. J Clin Periodontol 21: 571-576
  3. TibbettsJ, Allen K, Hausmann E: Effect of x-ray angulation on radiographic periodontal ligament space width. J Periodontol 63: 114-117, 1992
  4. GreensteinG, Polson A, et al: Associations between crestal lamina dura and periodontal status. J. Periodontol. 52:362-366, 1981.

Radiographs to detect progression of periodontitis

  1. Selikowitz H-S, et al: Retrospective longitudinal study of the rate of alveolar bone loss in humans using bite-wing radiographs. J. Clin. Periodontol. 8:431-438,1981.

Using radiographs to assess healing after periodontal surgery.

  1. Toback GA, Brunsvold MA, et al. The accuracy of radiographic methods in assessing the outcome of periodontal regenerative therapy. J Periodont 70:1479-1489,1999.
  2. Zybutz M, Rapoport D, Laurell L, Persson GR. Comparisons of clinical and radiographicmeasurements of inter-proximal vertical defects before and 1 year after surgical treatments. J Clin Periodontol 27:179-186, 2000.
  3. Grimard BA, Hoidal MJ, Mills MP, Mellonig JT, Nummikoski PV, Mealey BL. Compari son of clinical, periapical radiograph, and cone-beam volume tomography measurement techniques for assessing bone level changes following regenerative periodontal therapy. J Periodontol. 2009 Jan;80(1):48-55.
  4. Goren AD, Dunn SM, Wolff M, van der Stelt PF, Colosi DC, Golub LM. Pilot study: digital subtraction radiography as a tool to assess alveolar bone changes in periodontitis patients under treatment with subantimicrobial doses of doxycycline. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2008; Oct;106(4):e40-5. Epub 2008 Aug 20.

Radiographic measurements vs. clinical examination measurements.

  1. Goodson, M. “The relationship between attachment level loss and alveolar bone loss.” J Clin Periodontol 1984; 11: 348-359.
  2. Papapanou PN, Wennstrom JL: Radiographic and clinical assessments of destructive periodontal disease. J Clin Periodontol.16:609-612, 1989.
  3. Machtei EE, Hausmann E, Grossi SG, Dunford R, Genco RJ. The relationship and clinical changes in the periodontium. J Perio Res 32:661-666, 1997.
  4. Eickholz P, Hausmann E. Accuracy of radiographic assessment of interproximal bone loss in intrabony defects using linear measurements. Euro J Oral Sci 108:70-73, 2000.
  5. Pilgram TK, Hildebolt CF, et al. Relationships between radiographic alveolar bone height and probing attachment level: data from healthy post-menopausal women. J Clin Perio 27:341-346, 2000.

Comparison of Techniques

  1. Hausmann. Effect of x-ray beam vertical angulation on radiographic alveolar crest measurement. J Periodont Res 1989; 24: 8-19.
  2. Reed BE, Polson AM : Relationships between bitewing and periapical radiographs in assessing crestal alveolar bone levels. J. Periodontol. 55:22-27, 1984.

Reviews

  1. Kim DM, Bassir SH. When is cone-beam computed tomography imaging appropriate for diagnostic inquiry in the management of inflammatory periodontitis? An American Academy of Periodontology best evidence review. J Periodontol 2017;88:978-998.
  2. Mandelaris GA American Academy of Periodontology Best Evidence Consensus Statement on Selected Oral Applications for Cone-Beam Computed Tomography. J Periodontol. 2017 Oct;88(10):939-945.
  3. Tyndall DA American Academy of Oral and Maxillofacial Radiology. Position statement of the American Academy of Oral and Maxillofacial Radiology on selection criteria for the use of radiology in dental implantology with emphasis on cone beam computed tomography. Oral Surg Oral Med Oral Pathol Oral Radiol 2012;113:817-826.
  4. Benn DK. A review of the reliability of radiographic measurements in estimating alveolar bone changes. J. Clin. Periodontol. 17:14-21, 1990. (Review)
  5. Jeffcoat MK. Radiographic methods for the detection of progressive alveolar bone loss. J Periodontol 63: (Suppl 4) 367-372, 1992. (Review)
  6. Tugnait A, Clerehugh V, Hirschmann PN. The usefulness of radiographs in diagnosis and management of periodontal diseases: a review. J Dent 28:219-226, 2000. (Review)
  7. Kim IH, Mupparapu M.Dental radiographic guidelines: a review.Quintessence Int. 2009 May;40(5):389-98. Review


Are Radiographs an accurate method of diagnosing periodontal disease?

Topic: Furcation Arrow

Authors: Hardekopf J, et al.

Title: The “furcation arrow” – A reliable radiographic image?

Source: J.Periodontol.58:258-261,1986.
Type: Clinical study

Rating: Good

Keywords: Furcation Arrow, Radiograph

Furcation Arrow: Small triangular shadow across the mesial or distal roots of maxillary molars. Indicates class II or class III involvement.

P: To determine whether there is a consistent relationship between furcation arrows on radiographs and proximal bony furcation involvement in maxillary molars.

M&M: 45 adult human skulls with proximal furcation involvement in maxillary 1st or 2nd molars were used. 66 Degree 1, 53 Degree 2, 43 Degree 3 proximal furcation involvements. An additional 120 proximal furcations without bony involvement served as controls. Furcation classifications were determined independently by two examiners. Each maxillary molar was radiographed radiographed. Film placement was standardized to minimize interproximal overlap and to position the film lingually/palatally on a plane that paralleled the buccal surfaces of the teeth radiographed. Evaluations for the presence of the furcation arrow were made independently by 6 dentists as the radiographs were projected onto a screen. Projected radiographs with identifiable “arrow” images were used.

R: Incidence of furcation arrow image over degree 2 and 3 involvements was significantly greater than that observed over the uninvolved controls. The incidence of the furcation arrow image over the 120 uninvolved proximal furcations was low (18% for mesial and 7% for distal furcations). There was NSD between degree 1 involvement and the controls in the incidence of the furcation arrow image. There was an equal number of furcation arrows observed over mesial and distal furcations. The existence of a buccal furcation involvement of any degree did not influence the appearance of the furcation arrow. The image was no more likely to be observed over Degree 3 involvement than over Degree 2 involvement.

D: As the extent of furcation involvement increased, so did furcation arrow image. Degree 3 involvement reflected the radiographic image > 50% of the time. The furcation arrow seldom appears over uninvolved furcations, its appearance indicates that there is proximal bony furcation involvement. Absence of arrow does not indicate the absence of a bony furcation involvement. Root morphology and horizontal angulation of the tube head may be factors in determining whether a given furcation defect will exhibit an arrow.

BL: The radiographic presence of the furcation arrow appears to be a reliable diagnostic tool for the clinician when evaluating bony furcation involvement.

Topic: Furcations

Authors: Deas DE, Moritz A., Mealey B

Title: Clinical reliability of the furcation arrow as a diagnositc marker.

Source: J Periodontol 2006;77;1436-1441

Type: Clinical study

Rating: Good

Keywords: Furcation involvement, periapical, bitewings

B: Traditionally, radiographic assessment in conjunction with clinical probing using a curved explorer or furcation probe has been the chief diagnostic methods used for detecting and characterizing furcation involvement.

P: To evaluate the furcation arrow in a clinical setting, with emphasis on testing the assertion that the radiographic presence of a furcation arrow reliably identifies a furcation invasion.

Questions answered: 1. What is the prevalence of furcation arrow images in the radiographs of maxillary molars with periodontitis? 2. What is the interexaminer agreement on what constitutes a furcation arrow? 3. How does the presence or absence of a furcation arrow correlate with the true clinical status of the furcation? 4. What is the sensitivity and specificity of the furcation arrow as a diagnostic indicator?

M&M: 89 patients were referred between February 2004-June 2005 for treatment of moderate to advanced periodontitis that required surgical access to at least one maxillary posterior sextant. Before surgery, one of five calibrated examiners viewed PA and BW radiographs of the surgical site and recorded the presence or absence of a furcation arrow at each proximal furcation. Before administering anesthesia, the same examiner recorded a Hamp index value of each proximal furcation. After flap reflection and debridement, the examiner recorded a second Hamp index at each proximal furcation. After surgery, each of the four remaining examiners independently reviewed the radiographs for furcation arrows. Descriptive statistical analysis was performed to correlate the appearance of the furcation arrow image to the actual degree of furcation invasion as determined by the intrasurgical Hamp index.

R:

  • 164 maxillary molars were examined, providing 328 interproximal furcations
  • 111/328 (33.8%) furcations were determined at surgical debridement to have a furcation invasion of Hamp degree of 1 or greater.
  • When comparing the appearance of the radiographic image to the extent of furcation invasion, 20/64 (31.3%) Hamp 1 furcation invasions and 23/47 (48.9%) Hamp 2 and 3 furcation invasions were predicted by furcation arrows observed by at least three of five examiners.
  • The multirater k statistic for interexaminer agreement on the presence or absence of the image was 0.489 (low)
  • The sensitivity of the furcation arrow image as a diagnostic marker was 38.7%, and the specificity was 92.2%  Most actual furcation invasions were not associated with a furcation arrow: a high number of false negatives. The absence of a furcation arrow had a much higher likelihood of not having an accompanying furcation invasion present: a low number of false positives.
  • The positive predictive value of the image was 71.7%, and the negative predictive value was 74.6%.
  • Of the 324 furcations used to compare clinical indices, the agreement of pre-anesthesia and post-debridement Hamp indices was 0% for degree 3, 83.7% for degree 2, and 98.4% for degree 1 furcation lesions.

C: Clinical probing, post-anesthetic sounding and surgical access provide more diagnostic data about furcations than the radiographs to the clinicians. The image is difficult to interpret and highly subjective and can correctly predict furcation invasions only 70% of the time when present on the radiograph. In addition, when furcation invasions are truly present, the furcation arrow is seen in <40% of sites.

Topic: standardized radiographs

Authors: Ortman L, McHenry K, Hausmann E

Title: Relationship between alveolar bone measured by 1251 absorptiometry with analysis of standardized radiographs: 2. Bjorn technique

Source: J Periodntol 1982;53:311-314

Type: Skull study

Rating: Fair

Keywords: standardized radiographs, Bjorn technique

B: Bjorn developed a bone scoring technique using the projected 5x magnification of periapical radiographs on a scale which divides the tooth into 5% portions.

P: To compare the Bjorn and Henrikson (125I absorptiometry) techniques in their ability to detect small bone changes.

Omnell demonstrated that established principles of radiation absorptiometry permitted measurement of alveolar bone mineral mass. Henrikson applied these principles to development of an 125I absorptiometry technique capable of detecting alveolar bone mass changes on the order of 5%. The technique utilizes an essentially monoenergetic radiation beam, a collimating device and a scintillation counter for directly determining the amount of absorbed radiation.

M&M: 4 periodontal defects were created in dried human skulls between 1st and 2nd PM and 1st M of differing sizes, with incremental reduction of approximately 10%. The defects were made either by reducing the buccal wall or creating crater like defects and were measured using both of the techniques utilizing stents for standardization.

R: In initial bone loss, the Bjorn technique consistently underestimated the amount. 53% of the bone as measured by 125I absorptiometry needed to be reduced before the Bjorn technique could detect any loss. In advanced bone loss, the Bjorn technique was shown to overestimate the amount of loss in 2 of the sites and underestimate in the two other sites.

Conclusion: When bone loss is under 30%, the Bjorn technique tends to underestimate how much true loss has occurred and when over 60%, it is inconsistent.

Topic: Radiography

Authors: Buchanan SA, et al

Title: Radiographic detection of dental calculus.

Source: J Periodontol. 58:747-751, 1987

Type: Clinical

Rating: Good

Keywords: calculus, radiographs, sensitivity, specificity.
P: To quantify the sensitivity, specificity and observer error associated with radiographic detection of dental calculus on proximal surfaces of teeth in patients with severe periodontitis.

M&M: 18 patients that required extraction of at least 3 teeth because of severe periodontitis participated in the study. Excessively rotated or malpositioned teeth were not included in the study. Radiographic presence of calculus was determined by two examiners. After tooth extractions teeth were prepared and examined microscopically for calculus.

R: 275 proximal tooth surfaces and the corresponding radiographs were available for evaluation. Mean AL was 5.8mm.

Of the 153 surfaces with calculus noted visually, radiographically calculus was detected 43.8% (false negative 56.2%), (low sensitivity).

Of the 73 surfaces with calculus present radiographically, 91.8% were determined calculus present clinically.

Of the 160 surfaces assessed radiographically as calculus absent, 46.3% were verified by visual examination to have no calculus.

Radiographic evaluation of calculus was not an effective diagnostic method in most surfaces with thin or moderate deposits.
C: Conventional radiographs are a poor diagnostic method for detection of calculus. Radiographic analysis predicted calculus on less than half of the proximal surfaces where deposits were present visually.

What alveolar crest level represents bone loss on a bitewing radiograph??

Topic: Radiographic measurement of bone

Author: Hausman E., Allen K., Clerehugh V.

Title: What alveolar crest level on a bite wing radiograph represents bone loss?

Source: J Periodontol 1991;62;570-572

Type: RCT

Keywords: bone level, radiographic interpretation
P: Compute the distance from the CEJ to the alveolar crest on radiographs at sites where there was no clinical loss of attachment.

M&M:

  • Bitewing radiographs were taken on 68 pts (13-14 years old). A second set of radiographs were taken 18 months later.
  • The radiographs were taken using a routine unstandardized clinical technique and were processed under standardized conditions using a Refrema processing machine.
  • At each radiographic examination probing attachment level measurements were made at the mesio-buccal surfaces of the first molar teeth. Only the sites with zero attachment loss (attachment at the level of the CEJ) at both baseline and at 18 months were included in this study. A total of 134 sites included in the study.
  • A computer program was developed to measure the CEJ-crest distance (mm) in a line parallel to the long axis of the tooth.

R: The mean radiographic CEJ- alveolar crest distance (mm) for the 134 sites with zero loss of clinical attachment was 1.11 ±0.37 mm. at the initial examination and 1.19 ±0.34 mm at the same sites examined 18 months later . The 95% confidence limits were 0.4 mm to 1.9 mm.

BL: No crestal bone loss is consistent with a range of CEJ- alveolar bone crest distance between 0.4 and 1.9 mm as evidenced on bitewing radiographs.

Topic: Alveolar Crest

Author: Ritchey B, Orban B.

Title: The crests of the interdental alveolar septa.

Source: J Periodontol 1953;24:75-87.

DOI: 10.1902/jop.1953;24:75-87

Type: Discussion

Purpose: To focus attention upon the interpretation of roentgenograms (radiographs) of the crests of the interdental alveolar septa by describing and discussing the effects 1) variations in the anatomy and position of the teeth, 2) the common disease states, and 3) disharmonies in occlusion.

Discussion:

Tooth anatomy and tooth position:

  • Variations in tooth anatomy and position influence the contour of the interdental septa.
    • Shape and size of crowns
    • State of eruption
    • Position of teeth
  • Flat approximating root tooth surfaces create a narrow septa.
  • Convex teeth are supported by wide columns of interdental bone.
  • The alveolar crests may be relatively narrow when crowns are less highly contoured.
  • Bony crests tend to follow the slant between the CEJs of adjacent teeth.
  • State of eruption can also affect the shape of the crest which will change overtime.
  • Inclination of the teeth will also affect the slant of the interdental septa.

The alveolar crest in disease states:

  • A scalloped crest can indicate inflammatory alveolar resorption.
  • Extensive bone loss often involving only one side of then interdental septa is representative of degenerative processes in the supporting tissues (periodontitis).
  • The entire septum can also be involved, which will be seen asa more horizontal bone loss pattern.
  • Lack of radiographic change does not necessarily indicate absence of disease.
  • Degenerative changes may occur only at isolated sites or throughout the entire dentition.

Occlusal disharmonies:

  • Various theories exist on this topic.
  • Radiographic evidence of occlusal trauma/disharmonies is often evident as widening of the periodontal ligament.

Conclusion:

  • In the absence of periodontal disease, the configuration of the crests of the interdental alveolar bone septa are determined by the relative positions of the CEJ.
  • In the presence of periodontal disease alterations in the configuration of the interdental alveolar septa are governed principally by the specific pathologic process.
  • Assuming mesial and distal contacts between the teeth, no correlation is believed to exist between occlusal disharmonies and the radiographic appearance of the crests of the interdental alveolar septa.

Are digital radiographs equivalent to conventional radiographs in revealing bone loss?

Topic: Radiographic Interpretation

Authors: Khocht A, Janal M, Harasty L, Chang K:

Title: Comparison of direct digital and conventioanl intraoral radiographs in detecting alveolar bone loss.

Source: J Am Dent Assoc 2003;134;1468-1475

Type: Clinical Study

Rating: Good

Keywords: conventional radiographs, digital radiographs

P: To compare direct digital (D) and conventional (C) radiographic estimates of alveolar bone under normal clinical use.

M&M: 25 subjects with perio with age range b/w 18-65 years and had full set of PAs and BW for diagnostic purpose and tx planning. All subject had min of 15 teeth without any intraoral pathology or systemic dz. A long cone parallel technique was used to take PAs and a paper sleeve with biting tab was used for BW. Within 4 weeks, a second set PAs and BW was taken with digital system (Shick). The distance from the CEJ (surfaces with non-identifiable CEJs due to restorations or overlapping were excluded) to the interproximal alveolar crest (where the PDL space ends on the root surface) was measured. 3rd molars were excluded. One examiner measured with a plastic ruler on the C x-rays while another examiner measured the D x-rays. Overall % agreement of first and second readings in C x-rays was 99 and it was 92 for the D images. The examiners performed their measurements independently from each other. Each examiner measured the conventional or digital radiographs twice and took two sets of measurements for each subject. The examiners took the second set of measurements without having access to the initial set.

R: Examiner measured 857 PAs and 315 BW image sites match on both radiographic systems.

  • Measurements in the D images for BW averaged about 0.3mm greater bone loss than did C x-rays.
  • For BW, the difference between C x-rays and D was not found in all mouth sextants.
  • Rather, more bone loss was indicated by D x-rays only in the posterior mand region (BW); measures in the posterior maxillary region were similar between the two methods.
  • Measurements from C PA images showed more bone loss in all max sextants.
  • Categorical bone levels (normal<3 mm, early-to-moderate loss 4-6mm and advanced loss>7mm) were assigned to evaluate how each rx method revealed bone level and loss. Agreement between D and C x-rays in revealing bone levels as normal or having early-to-moderate loss was low (D x-rays revealed more early-to-moderate sites).

It seems that digital radiographs impart a constant addition of millimeters to measures taken in the posterior mandibular.

C: Under normal clinical use and without standardized film positioning, the average bone level measurements varied SS between C and D radiographs in certain regions of the mouth and that the disagreement between these two systems is influenced by the type of image PA or BW as well.

Cr: It is very difficult to take x-rays at the exact same angle with the sensor/film in the exact same place to compare measurements. Also, there may be error in calculating exactly where the CEJ is on the x-ray. The digital sensor is a different size, not flexible, and can be more difficult to position than conventional films. Having the USB cord attached to the digital sensor may interfere with subjects biting down on the BW tabs.

Topic: radiographic alterations

Authors: Bruder G, Casale J, Goren, A, Friedman S

Title: Alteration of computer dental radiography images

Source: J Endod 1999;25;275-276 DOI: 10.1016/S0099-2399(99)80159-9

Rating: good

Keywords: radiography, distortion, digital images, alterations

P: to determine if digital images could be exported, altered, and then restored without visible signs of alteration

M&M: Images were exported from the computer radiography program, files were altered, then files were restored to the Schick format and printed

D: Digital images are relatively easy to export and alter with the use of a photo editing program. The need to implement technologies to safeguard digital radiography must be addressed to prevent potential abuses.

Are panoramic radiographs ever of value in periodontics?

Authors: Akesson, L., Hakansson, J., Rohlin, M.

Title: Comparison of panoramic and intraoral radiography and pocket probing for the measurement of the marginal bone level

Source: J Clin Periodontol. 1992; 19(5):326-32

DOI: 10.1111/j.1600-051X.1992.tb00654.x

Type: clinical

Keywords: radiography, panoramic; dental; periodontitis periodontal bone loss

Purpose: to compare marginal bone level measurements and probing using panoramic, bitewing and periapical radiography.

Methods: Patients were enrolled with chronic periodontal disease. Sites with PDs >6mm at the re-eval were considered for surgery and included in the study. 237 sites of 23 patients were examined. Radiographs were taken with splint containing steel balls to allow calculation of the enlargement of the radiographs. Probing was done before and after flap surgery and open bone measurements represented true value.

Results:

Enlargement: The average enlargement of panoramic radiography was 27% in the maxilla and 26% in the mandible (NSSD). For both bitewing and periapical radiographs, there was 8-9% enlargement in the maxilla and 4-5% in the mandible (SSD).

Accuracy: Probing bone level was the most accurate method of assessing the marginal bone level. All methods of radiography underestimated bone loss but periapicals were most accurate compared to bitewings and panoramics.

Conclusion: The clinical implications of radiography in the diagnosis of periodontal disease twofold: To visualize the initial status of bone tissue and to see changes in bone over time. The authors agree that panoramic radiography is a good method for visualization of marginal bone level in patients with severe marginal bone loss, but periapicals are recommended for bone tissue change observation.

Topic: Radiographs

Author: Kasaj A., Vasiliu Ch, et al

Title: Assessment of alveolar bone loss and angular bony defects on panoramic radiographs

Source: Eur J Med Res. 2008 Jan 23;13(1):26-30

Type: Prospective study

Rating: Good

Keywords: Panoramic radiographs, angular bony defects, periodontal disease, bone loss

P: To investigate the prevalence and severity of alveolar bone loss and angular bony defects in randomly selected panoramic radiographs.

M&M: 500 panoramic radiographs of adult patients were studied. The mean age of the subjects was 51 years (range 20-80). Panoramic radiographs were placed on an x-ray viewer and evaluated by the same examiner. A calibrated periodontal probe was used to assess horizontal and vertical defects. If the interproximal projection of the CEJ was not identifiable, the apical termination of the restoration or crown margin was used for the measurements. A site was considered as having an angular bony defect if the bottom of the oblique radiolucency was located at least 2mm apical to the most coronal level of the interproximal alveolar bone.

R:

-In majority of subjects (86.7%) had some form of bone loss (horizontal and vertical).

–Angular bony defects were found in 49.8 % of the patients.

-Angular defects were more present in the mandible than in the maxilla, most frequently in the mandibular posterior, and least frequently in the mandibular anterior.

-The mean depth of the angular bony defects was 6.0 mm with the greatest mean depth in the maxillary anterior area (6.8 mm).

-The mean M-D width of the intrabony defects was 2.44 mm, and was most pronounced in maxillary molars (3.1 mm).

-Female subjects exhibited a gradual increase of vertical defect with age whereas in male subjects vertical bone loss was most prevalent in the age group 40-60 years and decreased in the older age group (60% vs. 40%).

-Interradicular molar radiolucencies demonstrated 38.3 % of the subjects and were more frequent in the md (first molar) than mx.

C: This study demonstrated a high prevalence of angular bony defects found on panoramic radiographs suitable for regenerative periodontal treatment.

Topic: Radiography

Authors: Persson RE, Tzannetou S, Feloutzis AG, Brägger U, Persson GR, Lang NP

Title: Comparison between panoramic and intra-oral radiographs for the assessment of alveolar bone levels in a periodontal maintenance population

Source: J Clin Periodontol. 2003. 30(9):833-9

Type: Clinical study

Rating: Good

Keywords: orthopantomogram; radiographs; alveolar bone level; diagnosis; periodontitis; maintenance population; agreement

P: To assess the level of agreement between intraoral and panoramic radiograph for direct measurements of the distance between the CEJ and the alveolar bone level (BL) as well as the proportional relationship (CEJ-BL/root length) and to explore the symmetry between left and right sided measurements.

M&M: Intraoral (IO) and panoramic (OPG) images were obtained from 292 patients on maintenance therapy. Two examiners performed measurements on digitally processed images. The distance between the CEJ and marginal BL was measured at the mesial and distal aspects of each tooth. The distance between the CEJ and apex of the tooth was also measured. The proportional distance between CEJ and BL relative to the length of the root was calculated.

R: All measurements between the two examiners showed no statistically significant differences. The largest mean proportional difference between CEJ and BL was seen in the maxillary right posterior segment, suggesting advanced periodontal disease in these sites. The largest difference between IO and OPG reading was observed between measurements for the maxillary anterior sextant, while the smallest difference was seen in the mandibular anterior sextant.

C: The study suggests that BL measurements between IO and OPG radiographs are highly comparable. The mean differences observed for the distance CEJ-BL in proportion to root length were neither statistically nor clinically different. A significant degree of symmetry of alveolar bone loss between the left and right side of the dentition was also found.

When should cone beam computed tomography (CBCT) be used?

Topic: CBCT

Authors: Walter C.

Title: Accuracy of three-dimensional imaging in assessing maxillary molar furcation involvement.

Source: J Clin Periodontol. 2010 May;37(5):436-41

DOI: 10.1111/j.1600-051X.2010.01556.x

Type: Clinical study

Keywords: Furcation involvement, cone beam, computed tomography

Purpose: To assess the accuracy of cone beam computed tomography (CBCT) in detecting furcation involvement (FI) in maxillary molars.

Methods:

  • 14 patients (5 females, 4 males, mean age 57) with generalized advanced chronic periodontitis were treated non-surgically.
  • Total of 14 first and 11 second maxillary molars with 75 furcation entrances
  • Complete clinical and radiographic examinations performed by 2 periodontists.
  • Non-surgical performed 6 months before study on teeth with PD ≥4mm. All patients were placed on SPT q3-4months.
  • Periodontal surgery was considered for sites with PD ≥6mm or increased FI. These patients were further evaluated using CBCT.
  • Furcation surgery was performed in 25 maxillary molars.
  • Intra-surgical FI assessments were compared with data derived from CBCT images.

Results:

  • CBCT analysis revealed 59 FI out of 75 furcation entrances. 9 FI grade I, 5 grade II and 45 grade III.
  • Overall, 84% of the CBCT data were confirmed by the intra-surgical findings.
  • While 14.7% (11 sites) were underestimated (CBCT less than intra-surgical value), in only 1.3% (1 site) did the CBCT data lead to an overestimation compared with the intra-surgical analysis.
  • The agreement between both assessments was the highest in distopalatal furcation entrances, followed by buccal and mesiopalatal.

Conclusions: CBCT images demonstrate a high accuracy in assessing the loss of periodontal tissue and classifying the degree of FI in maxillary molars.

 

Topic: CBCT

Authors: Walter C.

Title: Does three-dimensional imaging offer a financial benefit for treating maxillary molars with furcation involvement? A pilot clinical case series.

Source: Clin Oral Implants Res 2012 ;23:351-358.

DOI: 10.1111/j.1600-0501.2011.02330.x.

Type: clinical

Keywords: 3D imaging, cone beam computed tomography, cost benefit analysis, maxillary furcation surgery

Purpose: To analyze the financial benefit of CBCT for treatment options in posterior maxillary region.

Methods:

  • 12patients with generalized chronic periodontitis
    • 11 1st and 11 2nd maxillary molars with 66 furcation entrances
      • > 1 maxillary molar with persisting increased PD (> 6 mm) and/or advanced furcation involvement (Hamp degree II or III), were considered included
    • CBCT was performed and treatment proposed by periodontist
    • Treatment also proposed by periodontist who did not view CBCT and only examined clinically
      • minimal and a maximal invasive therapyrecommended

Results:

  • For the average number of minimal and maximal invasive treatments, CBCT resulted in average cost reduction of 915 Swiss Frances currency and an average time reduction of 136 minutes

Conclusion:

  • CBCT-based treatment decisions for maxillary molars may lead to an overall reduction in treatment costs and time compared with the treatment decisions resulting from clinical and plain film diagnosis only
    • cost and time reductions were smaller for minimal invasive clinically based treatment decision
    • greatest differences were found among the 2nd molars in the group of maximal invasive treatment
    • CBCT has been validated clinically and proven to be accurate in classifying the degree of FI in maxillary molars in humans
    • benefits of using CBCT are important for cost/time because the indication for tooth extraction is clarified
      • tooth extraction followed by implant placement and restorations is possible, thus avoiding explorative surgeries when the tooth is hopeless
      • unnecessary tooth extractions and implant placement in sites where teeth would be maintainable is avoided
      • root-canal treatments in sites planned for separation, amputation or trisection maybe prevented

 

Topic: Radiographic Bone Levels

Author: Grimard B.A.

Title: Comparison of clinical, periapical radiograph, and cone-beam volume tomography

measurement techniques for assessing bone level changes following regenerative periodontal therapy

Source: J Periodontol 2009;80:48-55

DOI: 10.1902/jop.2009.080289

Type: Randomized Control Trial

Keywords: bone regeneration, diagnosis, imaging, radiology

Purpose: To compare the linear measurements of periodontal defects and treatment outcomes for intraoral radiographs (IR) and cone-beam volumetric tomography (CBVT) images to the same direct surgical measurements that served as the study’s gold standard.

Methods:

  • Compare demineralized freeze-dried bone allograft (DFDBA) alone versus a combination of enamel matrix derivative and DFDBA.
  • 12 females with moderate to severe periodontitis showing at least a 3mm vertical defect on a radiograph were included in the study.
  • Patients received phase 1 therapy, had a 20% plaque score, then a surgical phase that included measurements during surgery as well as a re-entry surgery after 6 months.
  • IR and CBCT were acquired within a week of surgery and the same defect measurements made intraorally were made using IR and CBCT images, measurements were recorded at the re-entry surgery as well.

Results:

  • 95% of the duplicated surgical measurements were less than 1mm of difference between examiners.
  • 29 patients completed the study comprising 35 defects.
  • Majority of the defects were in the mandible in the premolar-molar region and were mainly a combination defect.
  • Comparing surgical measurements to IR and CBCT showed higher correlation coefficients and narrower intervals for CBCT.
  • No differences existed between surgical CEJ to alveolar crest (AC) measurements for either CBCT or IR.
  • All radiographic measurements from CEJ to AC were overestimations except for re-entry CBCT measurements.
  • CEJ to bone defect, defect fill and defect resolution were all underestimations compared to surgical measurements, and CBCT showed the closest to surgical measurements.
  • SSD between CEJ and bone crest when comparing surgical measurements to IR and CBCT, but no SSD for bone fill and defect resolution.
  • Mean difference between IR measurements and CBCT measurements compared to surgical measurements was 0.8mm and 0.4mm.
  • CBCT was significantly more accurate than IR at the less than 1mm and less than 2mm thresholds for almost all measurements.

Discussion: CBCT is an equivalent substitution for re-entry surgical measurements of bony changes occurring after grafting when looking at bone fill and resolution with less invasiveness but also not allowing further pocket reduction if necessary.

Topic: CBCT in dentistry

Authors: The American Dental Association Council on Scientific Affairs

Title: The use of cone beam computed tomography in dentistry: An advisory statement from the American Dental Association Council on

Scientific Affairs.

Source: J Am Dent Assoc 2012;143;899-902
Type: Discussion

Keywords: CBCT, ALARA

ADA Council on scientific affairs 2012: The use of CBCT in dentistry

CBCT imaging provides three-dimensional volumetric data construction of dental and associated maxillofacial structures with isotropic resolution and high dimensional accuracy.

A CBCT scanner uses a collimated x-ray source that produces a cone- or pyramid-shaped beam of x- radiation, which makes a single full or partial circular revolution around the patient, producing a sequence of discrete planar projection images using a digital detector. These two-dimensional images are reconstructed into a three-dimensional volume that can be viewed in a variety of ways, including cross-sectional images and volume renderings of the oral anatomy.

Although CBCT units produce a higher radiation dose than one would receive from a single traditional dental radiograph, the radiation dose delivered typically is less than that produced during a medical multichannel computed tomographic scan. CBCT radiation doses also vary widely according to the device used, x-ray energy and filtration, tolerance for image noise and motion artifacts and the size of the imaging area that is used to acquire volumetric data.

Principles for the safe use of dental and maxillofacial CBCT

– Should be used only after review of pt’s health, and imaging history and thorough clinical examination

– Should be used only after professional justification that the potential clinical benefits will outweigh the risks associated with exposure to ionizing radiation

-The clinician should prescribe traditional dental radiographs and CBCT scans only when he or she expects that the diagnostic yield will benefit patient care, enhance patient safety, sig- nificantly improve clinical outcomes or all of these.

-Should be considered as an adjunct to standard oral imaging modalities

– ALARA (As-low-as-reasonably-achievable) principle

– Should take every precaution to reduce radiation dose and ensure the patient’s safety. The use of thyroid collars and lead aprons is recommended when they do not interfere with the examination.

– Regardless of the primary purpose for the selection of CBCT, the complete image data set must be interpreted by a qualified health care provider. The prescribing clinician should receive a thorough radiological report

– Dental practitioners who use CBCT devices must receive appropriate training and education in the safe use of CBCT imaging systems

– Facilities using CBCT systems should consult a health physicist to perform equipment performance and compliance evaluations initially at installation and then follow a schedule in compliance with local, state and federal requirements

– Staffs of facilities using CBCT should establish a quality control program. This program can be based on the manufacturer’s recommendations

Topic: Radiograph

Authors: Misch KA, Yi ES, Sarment DP

Title: Accuracy of cone beam computed tomography for periodontal defect measurements.

Source: J Periodontol. 2006 Jul;77(7):1261-6.

Type: Clinical study

Rating: Good

Keywords: Periodontal defect, CBCT

P: To compare linear measurements of periodontal defects using CBCT to traditional methods.

M&M: 2 human dry cadaver skulls with existing horizontal bone loss up to 20% were examined. Infrabony buccal, lingual, and interproximal defects with varying width and height were created with a bur in mandibular molar and premolar regions. Grooves were also placed vertically into the roots from the CEJ to the depth of defect. Gutta percha cones were superglued into the grooves. CBCT (i-cat) and PA radiographs were taken.

Measurements were taken from A) CEJ-depth of pocket, B) CEJ to alveolar crest, C) width of the defect. Impressions of the defects were taken, and all measurements were compared to electronic caliper measurements. The accuracy of impression and caliper measurements were verified using another set of defects with known height and width prepared in cast acrylic blocks. Statistical analysis was done.

R:

All infrabony defects were detected using CBCT and the probe.

Average correlation was 0.4 for direct, 0.53 for PA, 0.62 for CBCT and 0.95 for impressions.

Correlation varied b/w 0.09 and 0.99 within examiners.

NSSD between all the methods for CEJ-depth of pocket, detection of isolated IP defects, and for buccal and lingual defects.

C: CBCT measurements compared well to traditional methods, with the advantage of allowing observation of defects in all directions. Further investigation is needed.

Topic: CBCT vs intraoral radiographs

Authors: Vandenberghe B, Jacobs R, Yang J.

Title: Detection of periodontal bone loss using digital intraoral and cone beam computed tomography images: an in vitro assessment of bony and/or infrabony defects.

Source: Dentomaxillofac Radiol. 2008 Jul;37(5):252-60.

Type: Skull study

Rating: Good

Keywords: periodontium, crater, furcation involvement, intraoral radiography, cone beam computed tomography

P: To determine the diagnostic values of digital intraoral radiographs and cone beam CT (CBCT) in the determining bone loss, infrabony defects, and furcation involvement.
M&M: A cadaver head with upper and lower jaws fixed with 10% formalin and a dry skull covered with a soft tissue substitute were used to measure 71 selected periodontal defects. To assess bone levels, the CEJ was used as a reference point for the fixed jaws, and gutta-percha fixated onto the buccal and lingual of teeth for the dry skulls. Intraoral radiographs were obtained with standardized bite blocks. CBCT was obtained with I-CAT. For the CBCT the observation were made on a 5.2 mm panoramic reconstruction view and on .4mm thick cross-sectional slices. First part of the study: 43 randomly selected sites with linear or vertical defects were chosen for radiographic and CBCT assessment of the bone loss and compared to the actual measurements. Second part of the study, 11 teeth containing vertical defects or furcation involvement was compared to actual measurements. The defects were categorized by 1, 2, 3 and 4 walls and the furcations by class 1, 2,3. Readings were performed by 3 examiners a medical imaging master and PhD student, and two radiology faculty members.

R: No intra- or interobserver effect was found. No significant differences were found when comparing the radiographs with those on the panoramic reconstruction image of the CBCT. The mean error for bone level measurements was 0.56 mm for radiographs, 0.47 mm for the CBCT panoramic view and 0.29 mm for the .4mm thick cross-sectional slices. SSD between the cross sectional slices and the radiographs. The detection of crater and furcation failed 29% and 44% with radiographs, and 0% with CBCT.

C: CBCT allowed more accurate assessment of periodontal bone loss.

What if the significance of the lamina dura?

Topic: Radiograph

Authors Van der Linden, L., Van Aken, J.

Title: The periodontal ligament in the roentgenogram.

Source: J Periodontol 1970; 41:243-248

DOI: 10.1902/jop.1970.41.5.243

Type: Clinical study

Keywords: periodontal ligament, width, radiographs, periodontal disease

Purpose: To examine how root shape, thickness of the jaw, exposure time, and quality of the x-ray influence the interpretation of the width of the periodontal ligament as seen in the roentgenogram.

Methods: Models were constructed with different dimensions of the width of the periodontal ligament, the radius of the circumference of the root and the thickness of the jaw. Aluminum, plaster of paris and wax were used as substitutes for dentin, bone and the soft tissues. Four series of roentgenograms (radiographs) were made. In each series two or more factors were changed. The images were placed in separate mounts which left only a circular area across the PDL visible to the observer. 21 observers interpreted the films with the following criteria: examine the films, irrespective of the difference in blackening, for differences in width of the periodontal ligament. If differences in width can be found, put the films in order of increasing width.

Results:

  • Root curvature showed no difference in ranking by the examiners. For both the series with the thin and thick PDL an increased radius increases the subjective width in the radiograph (SSD).
  • Darker lines are interpreted as being wider and explains why a ligament of 0.15mm around a root with a radius of 10mm could not be distinguished from one twice as thick around a root with a small radius.
  • When jaw thickness is changed and the other factors kept constant, three of out the four comparisons show an interpretation which is an agreement with the anatomical situation.
  • Kilovoltage (KV) and exposure time showed an increase of subjective width with exposure time and the decrease with higher KV will compensate.
  • PDL width may be altered in its visual subjective width when the radius of the circumference is different, the exposure time is different and the kilovoltage is different.
  • Changing the horizontal angulation produces a radiograph showing a narrowing in the width of the uppermost part of the PDL. If rotated enough the alveolar bone will be projected over the root without a trace of the PDL.

Conclusion: Experimental radiographs made on models show that the visual impression of the width of the PDL is influenced by its blackening. The same width of the ligament can be interpreted as being different when the radius of the circumference is different, when the exposure time is changed or when the KV is changed.

 

Topic: Lamina dura

Authors: Rams

Title: Utility of radiographic crestal lamina dura for predicting periodontitis disease activity.

Source: J Clin Periodontol 21: 571-576

DOI: 10.1111/j.1600-051x.1994.tb00745.x

Type: Discussion

Keywords: alveolar bone, radiology, radiography, panorex, panoramic radiography

Purpose: To evaluate the relationship between radiographic crestal lamina dura status and localized disease recurrence in previously treated adult periodontitis patients on maintenance over a 36-month period.

Methods:

  • 51 adult patients treated for moderate to advanced periodontitis were enrolled in 3-month maintenance program for 36 months.
  • The presence or absence of crestal lamina dura at 1809 interproximal sites was recorded from periapical and bitewing radiographs taken at baseline.
  • Semi-annual clinical evaluations by 2 independent examiners were carried out on each patient,
  • Recurrence periodontitis disease-activity was defined as sites revealing an increase of ≥3mm in PD from baseline, or an increase of ≥2mm in PD together with ≥2mm loss of CAL from an occlusal reference stent.

Results:

  • 1809 of the 2332 interproximal tooth sites were scored for crestal lamina dura from baseline radiograph.
  • Crestal lamina dura present at 303 sites and absent at 1506 sites.
  • Disease recurrence detected in 23 (45%) patients at 55 (3%) interproximal tooth sites scored for baseline crestal lamina dura.
  • Absence of detectable baseline crestal lamina dura yielded high sensitivity (87-100%), but low specificity (17%) and low positive predictive values (0.8-3.2%), for localized periodontitis recurrence.
  • Presence of baseline crestal lamina dura demonstrated no periodontitis recurrence up to 24 months from baseline (100% positive predictive values of periodontal stability).
  • Presence of radiographic crestal lamina dura was positively associated with clinical periodontal stability (odds ratio for sites = 2.6), and negatively associated with periodontitis recurrence (odds ratio for sites = 0.4), for the 36-month study period.

Conclusion: Evaluation of radiographic crestal lamina dura status appears valuable for assessing the risk of periodontitis disease-activity at interproximal tooth sites in patients on maintenance care programs

Topic: Lamina Dura

Authors: Tibbetts J, Allen K, Hausmann E

Title: Effect of x-ray angulation on radiographic periodontal ligament space width

Source: J Periodontol 63: 114-117, 1992

Type: Clinical

Rating: Good

Keywords: Periodontal ligament/anatomy and histology; periodontal ligament/radiography.

P: To determine the influence of known changes in x-ray beam angulation anticipated under clinical conditions on the change in radiographic ligament space width. Radiographs of molars and incisors were studied to determine the influence of anatomical factors on changes associated with alteration in x-ray beam angulation

M&M: Pairs of radiographs were taken of incisor and molar locations in whole dried human skulls with known differences in x-ray beam angulation. To be acceptable, radiographs had to meet the following requirements: 1) no overlaps of contact areas of adjacent teeth, 2) visible interdental alveolar bone, 3) no cone-cut in the radiograph, 4) sufficient contrast to read any anatomic structures present. Baseline for vertical angulation was set perpendicular of the long axis of the tooth. For each tooth site, radiographs were taken at 2 vertical angulations: 1) perpendicular to tooth’s buccal surface 0° and 2) 10° off the perpendicular. 5 different horizontal angulations at each of the 2 indicated vertical angulations 1) baseline 0°, 2) -3° and -6° from the perpendicular, 3) +3° and +6° from the perpendicular. Replicate radiographs were taken at 0° and at each of the 2 vertical angulations. The radiographs were converted to digitized images and PDL width measurements were made utilizing a computer program. Data were analyzed separately for the incisor and molar sites.

R: The variation between the mean difference of baseline measurements was compared with that of discrepant-angle combinations, 10/20 pairs of radiographs which differed in horizontal angle only were significantly different from results of baseline replicates. 2/5 groups of pairs of radiographs which differed in vertical angle only were significantly different from results of baseline replicates. 11/20 groups of pairs of radiographs which differed in both vertical and horizontal angulation were significantly different from results of baseline replicates. Mean PDL width differences for incisor locations were SS from the mean baseline PDL width difference, posterior PDL width difference showed no statistical variation from the mean baseline width difference

C: Changes in x-ray angulation resulted in a SS change in radiographic PDL width at incisor locations, no such significant effect was found at molar locations. At molar area, thick bone overlying PDL will tend to reduce the difference in density seen on the radiograph of the ligament space and adjacent interproximal bone. It is suggested the radiographs should be taken with controlled projection geometry when clinical interpretation of change in PDL width is desired.
Topic: Lamina dura

Author: Greenstein G, Polson A, et al

Title: Associations between crestal lamina dura and periodontal status.

Source: J. Periodontol. 52:362-366, 1981.

Type: RCT

Rating: Good

Keywords: lamina dura, radiographic diagnosis, bitewing radiographs

P:To investigate the association between the radiographic presence of crestal lamina dura and the clinical periodontal status of the corresponding interdental area.

M&M:

  • 90 pts (53F, 37M; 21-45 years old) had 4 interproximal locations evaluated.
  • Sites were scored for visual inflammation, BOP, presence of PD> 3mm, and loss of attachment.
  • Bitewings and full mouthseries radiographs taken.
  • The radiographs were examined and scored for the presence or absence on an intact crestal lamina dura.

R: NSSD correlations were obtained between PA radiographs, presence of lamina dura and inflammation, PD, or attachment loss. On bitewings, there was a SSD between presence of crestal lamina dura and inflammation (81.9%) versus absence of crestal lamina dura and inflammation (72.5%). No SSD with the other parameters and bitewings. However, there were significant discrepancies on whether the crestal lamina dura was present (agreed 24% of the time) and agreed 89% of the time when absent.

BL: Radiographically, the crestal lamina dura did not appear to be related to the presence or absence of clinical inflammation, BOP, presence of pockets, or loss of attachment.

Can radiographs be used to detect progression of periodontitis?

Topic: Radiographic Interpretation

Authors: Selikowitz H-S, et al:

Title: Retrospective longitudinal study of the rate of alveolar bone loss in humans using bite-wing radiographs.

Source: J. Clin. Periodontol. 8:431-438,1981.

Type: Retrospective Study

Rating: Good

Keywords: periodontal disease, human, rates of alveolar bone loss, radiographs

P: To develop and evaluate a method for measuring the degree of alveolar bone destruction retrospectively using radiographs and to use the method to assess bone loss over periods exceeding 10 years.

M&M: 100 pairs of BW x-rays obtained from patients of 2 general dentists in England on recall q 3 or 6 months for 10 years. Long cone paralleling technique was used. 3M reader was used to read the x-rays (6.59x magnification). An unexposed film with two points 0.3mm apart as measured with a travelling microscope was used to standardize measurement on each radiograph. 2 reference points were used–the highest point on the occlusal surface of the crown and the M and D points on the CEJ. 80 of the cases were assessed using an abbreviated index as described by Bjorn 1975 (they found that the arithmetic means of mesial and distal scores from the mand M and PM regions correlated well with the means of the whole dentition). Bone heights were assessed on x-rays taken 10 years apart.

R: The percentages of measurable distances between tooth reference points and bone levels varied form 35%, using occlusal measurement point, to 49%, using the CEJ reference point. Bone levels around the 1st PM were the most unreadable.

Average bone loss per year

Horizontal Vertical

Occ 0.06mm 0.05mm

CEJ 0.04mm 0.03mm

Annual bone loss measurements fluctuated, some even gained. Radiographic bone loss underestimates CAL.

BL: BW’s can be used in longitudinal studies of perio dz and can provide important info on the progression of perio disease (since the findings of bone loss were consistent with the rates of attachment loss reported by several other authors that used probes).

Are radiographs an accurate way to assess healing after periodontal surgery?

Do newer radiographic techniques improve the usefulness of radiographs?

Topic: radiographic accuracy

Authors: Toback GA, Brunsvold MA, no ARTICLE

Title: The accuracy of radiographic methods in assessing the outcome of periodontal regenerative therapy.

Source: J Periodont 70:1479-1489,1999 DOI: 10.1902/jop.1999.70.12.1479

Type: clinical

Rating: good

Keywords: bone regeneration; periodontal disease/therapy; outcome assessment; comparison studies; radiography, dental methods; follow up studies.
P: to determine the ability of 2 forms of radiographic analyses (linear measurements and computer assisted densitometric image analysis, CADIA) to assess postsurgical bone fill in comparison to measured bone fill at a re-entry procedure.
M&M: 15 patients each with 3 separate sites.

  • Sites were randomly assigned to 1 of 3 treatment groups: DFDBA + tetracycline, DFDBA alone and open flap debridement (OFD)
  • Osseous defects were measured during surgery from a fixed reference point, to the base of the defect. Sites were allowed to heal for 12 months. A re-entry procedure was conducted to repeat the measurements
  • Stanardized radiographs (vertical bitewings) were taken at baseline and just prior to re-entry
  • CADIA: Changes in bone density at each of the areas of interest were compared with clinical measurements of bone fill obtained at the re-entry procedure.
  • Linear radiography: CARE software was used, 2 periodontists and 2 third-year periodontal residents performed the measurements.
  • Linear CADIA: CADIA has been shown to have a greater sensitivity to detecting changes in bone density than conventional radiographic evaluation.

R: Of the 45 pairs of radiographs, 24 were excluded, 21 remained, 15 in the mandible and 6 in the maxilla.

  • CADIA: a clear trend of increasing mean CADIA values for defects with increasing clinical bone fill was noted.
  • Linear radiographic measurements: Overall linear assessment underestimated post-treatment bone fill by 0.96 mm (statistically significant)
  • Linear-CADIA: a combination of both methods, on average this method underestimated bone fill by 0.26m (not statistically significant)

C: Linear radiographic measurement significantly underestimate post-treatment bone fill when compared to re-entry data. The linear-CADIA method provided the highest level of accuracy of the 3 methods tested.

D: It cannot be said with confidence that any of the radiographic methods evaluated in this study can serve as a replacement for the data obtained during a re-entry procedure.

No single radiographic method can reproduce similar information consistently

Topic: Radiographs

Author: Zybutz M, Rapoport D, et al.

Title: Comparisons of clinical and radiographic measurements of inter-proximal vertical defects before and 1 year after surgical treatments.

Source: J Clin Periodontol 27:179-186, 2000

Type: Clinical

Rating: Good

Keywords: probing bone; probing attachment level; radiographic bone level

B: Radiographic measurements are often used as a substitute for direct clinical measurements requiring surgical re-entry for follow up outcome studies.

P: There were 3 aims of this study:

  1. To assess the reliability of clinical and radiographic measurements of periodontal defects as compared to direct bone measurements during surgery.
  2. To assess associations between selected clinical and radiographic measurements of interproximal defects
  3. To assess if changes identified from probing to bone measurements could reliably be detected by other clinical and radiographic methods.

M&M:

-57 interproximal vertical defects from 29 patients were measured at baseline and 12 months after surgery (OFD or GTR procedures).

-Standardized PA x-rays were taken at both baseline and 12 months after surgery.

-During surgery, direct measurements from the CEJ to bottom of the defect-alveolar bone level (ABL) were taken, and then compared with probing to bone (PB), probing attachment level (PAL) and x-ray measurements.

-Using computer-digitized images, CEJ to bottom of defect (ABLX) and bone crest to bottom of defect (IBDX) were measured.

R:

-Probing to bone is an accurate measure to assess interproximal bone level as compared to ABL.

-Standardized PA’s underestimate bone level and defect depth by approximately 1.4mm.

-Interpretation of the periodontal changes between baseline and 12 months after treatment by probing to bone, or PAL measurements, or from images almost yield identical results (mean difference < 0.2mm)

BL: Both radiographic interpretations of changes over time, and measurements of attachment level changes are reliable in assessing treatment outcome of interproximal intra-bony defects when compared to probing to bone changes as the standard method.

Topic: Radiography

Authors: Grimard BA, Hoidal MJ, Mills MP, Mellonig JT, Nummikoski PV, Mealey BL

Title: Comparison of clinical, periapical radiograph, and cone-beam volume tomography measurement techniques for assessing bone level changes following regenerative periodontal therapy

Source: J Periodontol. 2009 Jan; 80(1):48-55

Type: Clinical study

Rating: Good

Keywords: Bone regeneration, diagnosis, imaging, radiology

P: To compare linear measurements of periodontal defects and treatment outcomesf rom intraoral (IR) and cone-beam volumetric tomography (CBVT) to direct surgical measurements at the time of surgery and at re-entry.

M&M: Subjects from a controlled clinical trial comparing outcomes of DFDBA alone vs. DFDBA and enamel matrix derivative were used in this study. Inclusion criteria were moderate to severe chronic periodontitis, at least one interproximal site with 5mm probing depth, and a vertical defect of greater than 3 mm on an IR. 35 grafts were available for re-evaluation. At he time of surgery (baseline), direct surgical measurements were taken. These measurements were completed at reentry greater than or equal to 6 months later. IR and CBCT were obtained at both surgical time points. Clinical measurements after flap reflection included CEJ to the coronal part of alveolar crest and CEJ to the base of the defect. The surgical measurements were considered the “gold standard” values that the radiographic measurements were compared to. Statistical analysis was performed.

R: 22 defects were present in the mandible, and 13 were in the maxilla, with the majority of defects in the canine/premolar or molar region. Most defects had a combination of defect wall numbers. All of the radiographic measurements from the CEJ to alveolar crest were overestimations of surgical measurements except for the reentry CBVT measurement. All of the remaining measurements (CEJ-base of defect, defect fill, defect resolution) were underestimated compared to direct surgical measurements. The CBVT measurements were closer to surgical measurements than those made from IRs. CBVT was significantly more accurate than IR at ≤1 and ≤2-mm thresholds for almost all hard tissue measurements.

C: For some bony parameters, no significant difference was noted between IR and CBVT measurements compared to surgical measurements. Results suggest that data gathered from CBVT images more accurately reflects bony defect dimensions than data from IR images, and measurements for defect resolution are not significantly different from surgical measurements. CBVT is an equivalent substitution for direct surgical measurements of bony changes occurring after bone replacement graft procedures, especially defect fill and defect resolution.

Topic: Radiographic interpretation of alveolar bone changes

Authors: Goren AD, Dunn SM

Title: Pilot study: digital subtraction radiography as a tool to assess alveolar bone changes in periodontitis patients under treatment with subantimicrobial doses of doxycycline.

Source: Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2008; Oct;106(4):e40-5. Epub 2008 Aug 20.
Type: Pilot study
Rating: Fair

Keywords: Digital Subtraction, radiography, alveolar bone changes

B: Digital subtraction radiography is a method of image enhancement, trying to produce 2 radiographic images of the same area of the mouth with the same angulation at different time intervals. The first image can then be subtracted from the second to assess changes that occurred during a particular time period. Minimal changes of loss or gain of hard tissue can be detected that would otherwise be undetectable by visual exam or traditional radiograph.

P: To evaluate the practical application of geometrically corrected digital subtraction radiography (DSR) in a clinical study of alveolar bone response to a 6 months regimen of subantimicrobial doxycycline or a placebo.

M&M: 11 patients were included. Half received low-dose-doxycycline (LDD) 20 mg regime for 6 months and half received placebo. PD and GI recorded at baseline, 3 and 6 months. 2 sites with PD >3 mm were imaged for each patient. Standardized radiographs were taken at 3 and 6 months and baseline radiographs were subtracted from these images.

R: Average PD in baseline was 4.6 mm and 4.9 mm for LDD and placebo group respectively. NSD between LDD and placebo at 3 months for both GI and PD. GI showed no change between 3 and 6 months. For PD, LDD appeared to remain stable between 3 and 6 months, whereas the placebo showed in increase in PD between 3-6 months (average change of 0.3 mm). Comparing the bone height gained/lost, the LDD group at 6 months showed on average less alveolar bone loss compared with placebo. 3/6 patients showed bone gain.

BL: Digital subtraction radiography has potential as a clinical method for evaluation of changes in alveolar bone level.

How do Radiographic Measurements Compare to Clinical Examination Measurements?

Topic: alveolar bone loss

Author: Goodson, J.M., Haffajee, A.D., Socransky, S.S.

Title: The relationship between attachment loss and alveolar bone loss

Source: J Clin Periodontol 1984; 11:348-359

DOI: 10.1111/j.1600-051x.1984.tb01331.x

Type: clinical radiographic study

Keywords: periodontal disease, attachment loss, bone loss

Purpose: To evaluate changes in attachment loss and alveolar bone loss using radiographic evidence.

Methods: 22 patients with untreated periodontal disease were monitored for 1 year. Standardized radiographs and repeated periodontal probe measurements were taken. Radiographs were taken at 0, 6 and 12 months. Clinical exam of attachment level was conducted monthly. Radiographs were standardized for angulation and film-source distance. Measurements were made on 7x enlarged images. Each radiograph was measured twice by 2 investigators. Changes in attachment level were computed for the intervals preceding and during the 6-12month radiographic measurement period.

Results: A total of 231 radiographic sites were measured. The critical value for bone loss was selected as 0.48mm. Based on the critical values, 6.1% of the 231 radiographed sites showed significant bone loss. None of the sites with significant bone loss exhibited significant attachment loss over the same time period. 7 of 10 sites with significant bone loss, had some change in attachment level in the measurement period.

Conclusion: In general, attachment loss preceded bone loss by 6 to 8 months. At 4mm attachment loss was strongly predictive of bone loss (true positive 60%). Radiographic monitoring did not predict future bone loss.

Topic: Radiograph

Authors Papapanou PN, Wennstrom JL

Title: Radiographic and clinical assessments of destructive periodontal disease.

Source: J Clin Periodontol. 16:609-612, 1989.

Type: Clinical study

Rating: Good

Keywords:

P: To compare results from radiograph and clinical estimations of the amount of periodontal tissue destruction.

M&M: 191 subjects (35-80 years old), 4,682 tooth sites were examined for periodontal disease using radiographic and clinical means. At all proximal tooth surfaces, assessment was made radiographically by measuring the distance from CEJ to the coronal level of alveolar bone on PAs (anteriors) and BWs (posteriors) and clinically by recording the CAL w/ a calibrated periodontal probe.

R:

  • Strong correlation existed between the radiographic and clinical assessment (r=0.80, p 0.0001)
  • The difference between the two types of assessment was within 2 mm in 92% of the teeth examined.
  • The degree of agreement was similar irrespective of tooth type and tooth surface.
  • The agreement became poorer at sites with severe periodontal tissue breakdown (deep pockets).

C: The amount of periodontal destruction is not necessarily underestimated in radiographs, but no definite conclusion regarding the over or under-estimation of the alveolar bone loss should be made with either method.

Topic: measuring disease progression

Authors: Machtei EE, Hausmann E, Grossi SG, Dunford R, Genco RJ. NO ARTICLE

Title: The relationship and clinical changes in the periodontium.

Source: J Perio Res 32:661-666, 1997.

Type: Longitudinal study

Rating: Fair

Keywords: disease progression, attachment loss, correlation

P: To evaluate the correlation between changes in CAL and alveolar bone loss in untreated pts with moderate to advanced periodontitis (longitudinal study).

M&M: 79 pts (44 female, 35 male) with IP CAL  6mm and PD  5mm, CAL and relative attachment level (RAL: a disk probe attached to the Florida probe. The occlusal table or incisal edge is used as a landmark from which all attachment measurements are being made) were measured at 6 sites on each tooth with Florida probe at baseline and every 3 months for one year. Radiographs were taken at the baseline and 1 year. Crestal bone height was analyzed using image enhancement technique.

R: Mean CAL change was 0.16mm, mean change in crest height was 0.16 mm. Mean percentage of IP active sites was 12.9% and 13.7% for radiographic and clinical measurements, respectively. Correlation analysis failed to demonstrate a significant correlation between CAL and radiographic bone loss. Measurement error may play a role in affecting this correlation.

D: Changes in CAL and radiographic crestal bone height progress independently over a short period of time, but seem to level off long term. Author suggests using both methods for longitudinal monitoring of dz progression and response to therapy, while for cross-sectional evaluation and long-term prospective studies, either or both variables may be used as independent but correlated measurements of destructive periodontitis. Even though same mean value for both parameters, they don’t correlate according to site based correlation analysis or patient based analysis. This may be due to measurement error, or maybe one occurs prior to the other (ej. bone loss before CALoss).

C: CAL and crestal bone height seem to progress somewhat independently over a short period of time, however, in the long term, these differences seem to level off. For longitudinal monitoring disease progression and response to therapy both CAL and radiographic changes may be needed.

Cr: x-rays non-standardized

Topic: Radiographs

Authors: Eickholz P, Hausmann E

Title: Accuracy of radiographic assessment of interproximal bone loss in intrabony defects using linear measurements.

Source: Euro J Oral Sci 108:70-73, 2000

Type: Clinical

Rating: Good

Keywords: alveolar bone loss; digital radiography; linear measurements; surgical measurements; periodontal diagnosis
P: 1) To assess the accuracy of linear measurements of interproximal bone loss on radiographs using a computer- assisted technique and 2) to identify factors influencing the accuracy of this method

M&M: 22 patients with untreated periodontal disease participated in the study. After initial treatment, vertical bitewing radiographs were taken to assess vertical bone loss. Before surgery PI, GI, PD and AL were assessed in 6 sites per tooth and during surgery after FTF reflection distances from CEJ to apical extension of bony defect (BD) and alveolar crest (AC) to BD were recorded. Linear measurements of CEJ-BD were performed by a computer assisted method. Factors that could affect the measurements accuracy (angulation difference, patient. Height of one-, two- and three-wall component) were investigated.

R: 33 radiographs with 34 IP defects were obtained. The radiographic analyzing technique significantly underestimated the amount of interproximal bone loss compared to surgical measurements (CEJ-BD by 1.4+/-2.6mm). The discrepancy between computer-assisted radiological measurements and surgical assessments was modulated by factors, such as vertical angulation difference, height of the two- walled component, and individual patients. The particular model explained 79% of the variation of the explanatory variable.

C: Within the limits of the present study, the following conclusions may be drawn: 1) the computer-assisted analysis of linear distances on radiographs underestimated the amount of inter- proximal bone loss as assessed by surgical measurements; and 2) it appears that there are no major differences between different computer- assisted analyses in underestimating interproximal alveolar bone loss.

Topic: Post-menopausal women

Author: Pilgram TK, Hildebolt CF, et al

Title: Relationships between radiographic alveolar bone height and probing attachment level: data from healthy post-menopausal women.

Source: J Clin Perio 27:341-346, 2000.

Type: RCT

Rating: Good

Keywords: post-menopausal women, radiographic appearance, diagnosis, attachment level, HRT

P: To determine cross-sectional and longitudinal relationships between radiographic alveolar bone height and probing attachment level in a healthy postmenopausal women population.

M&M:

  1. 81 patients in good oral health, perio pockets < 5mm, were part of an estrogen replacement interventional treatment.
  2. Pts received annual prophylaxis. Probing measurements with pressure sensitive probe at 6 sites.
  3. Vertical bitewings were digitized and 6 linear measurements made from CEJ to alveolar crest. Procedures performed at baseline and every year for 3 yrs.
  4. Data was analyzed by site and by patient

R:

  1. Moderately strong correlation between cross-sectional measurements in probing attachment level and radiographic alveolar bone height
  2. Correlations were stronger for patient data than for site data
  3. No relationships were found between longitudinal changes in alveolar bone height and attachment level in either the site data or patient data.
  4. Some sites gained attach and bone height. Estrogen may cause small gains in alveolar bone more likely result of systemic changes in bone health.

BL: Even a healthy mouth is relatively dynamic and may experience sporadic, temporary changes in attachment level and alveolar bone height which are resolved without affecting one another.

Comparison of Techniques

Topic: Lamina dura

Authors: Hausmann

Title: Effect of x-ray beam vertical angulation on radiographic alveolar crest measurement.

Source: J Periodont 1989 Res 24: 8-19

DOI: 10.1111/j.1600-0765.1989.tb00852.x

Type: Discussion

Keywords: alveolar bone, radiology, radiography, panorex, panoramic radiography

Purpose: to examine the effect of the vertical angulation of the x-ray beam on the radiographic image of the alveolar crest in dried human skulls

Methods and Materials:

  • Skulls placed in holding apparatus and x-rays taken of each alveolar crest
    • x-ray beam deviated0-degree, 10-degree, 20-degree, and 30-degree, from the 90-degree baseline.
  • Calculations for crest height were calculated
    • Cusp height score = (lingual cusp tip to CEJ) / (buccal cusp tip to CEJ) x 100%
    • Crest level measurements
      • Ratio method (bone score) = (bone height) / (root length) x 100%
      • Ratio method (bone score) = (bone crest to apex) / (CEJ to apex) x 100%
      • Direct method = crest to CEJ in mm

Results:

  •  the mean of cusp height scores for mx and md molars decreased progressively with a decrease in x-ray beam angulation
    • The scores were higher when determined on bitewings (68% between 125-99%)
    • The scores on PAs were lower (23% between 69-60%)
  • For molars, significant difference between crest level measured at 80-70 degrees versus 90-degrees
    • 95% of md and 68% of mx sites were radiographed with angulation of 90-degrees
  • Reproducibility of crest height measurements decreases as x-ray beam angle deviates from 90-degrees
  • The most accurate reproduction of the object is achieved when x-ray beam is perpendicular to object
  • Greatest frequency and magnitude of beam angulation deviation from 90-degrees occurs in mx PA x-rays
  • x‐ray beam angulation for posterior bitewings ranged between 90° and 60° whereas for posteriorPAs the angulation range was between 90° and 70°
  • it is recommended that, for longitudinal studies of bone height, measurements of the crest to CEJ distance, particularly in the region of the molars, be made using bitewing radiographs.
  • For the premolar and incisor regions, deviation of the vertical angulation of an x‐ray of up to 20° from a 90° baseline resulted in little, if any, change in crest level

Conclusions:

  • 10° shift of the film relative to line of x-ray projection results in only a 1.5% error in the radiographic projection of an anatomical distance between any two points.

Topic: Radiographic Interpretation

Authors: Reed BE, Polson AM

Title: Relationships between bitewing and periapical radiographs in assessing crestal alveolar bone levels.

Source: J. Periodontol. 55:22-27, 1984

Type: Retrospective Study

Rating: Good

Keywords:

P: To study the relationship between measurements of the level of alveolar bone crest obtained from PA’s vs. BW’s of the same interproximal areas.

M&M: 210 patients, 14 PA’s and 4 BW’s were taken on each individual using long cone paralleling tech with Rinn method of positioning the film. Evaluated all interproximal bone levels from the distal of 2 nd molar to distal of canines using projected images and mm rulers. PA and BW measurements were compared under 5.9x magnification.

R: 50% of mesial & distal surfaces were SSD from each other with BW measures being larger than PA’s 94% of time. The maxilla was less reproducible than the mandible, maxillary cuspids, mandibular 1 st premolars, and mandibular 1 st molar did not have a SSD between BW & PA for mesial or distal surfaces. The mean % difference between all BW and PA measures was 14.3%.

BL: BW and PA techniques give SSD values in assessing crestal bone levels. Author recommends these techniques not be used interchangeably.

Reviews

Topic: CBCT for diagnosis

Authors: Kim DM, Bassir SH.

Title: When is cone-beam computed tomography imaging appropriate for diagnostic inquiry in the management of inflammatory periodontitis?

Source: J Periodontol 2017;88:978-998

DOI: 10.1902/jop.2017.160505.

Type: Systematic Review

Keywords: Alveolar bone loss; cone-beam computed tomography; furcation defects; imaging, three-dimensional; periodontal disease; periodontitis

Purpose: To determine when cone-beam computed tomography (CBCT) imaging is appropriate for diagnostic inquiry in the management of inflammatory periodontitis.

Methods: Literature was systematically reviewed, with a search in MEDLINE, to answer these questions:

1) Clinical situation: In patients with periodontitis, what (if any) clinical situations/conditions exist where CBCT imaging improves diagnostic acumen and subsequent treatment recommendations compared with two-dimensional radiographic interpretation?

2) Intervention: Does CBCT imaging improve the accuracy of a diagnostic assessment and establishment of a prognosis in the analysis of furcation and/or intrabony defects? Is the execution of therapy improved and facilitated, or is it therapeutically challenged?

3) Outcomes: Does the use of CBCT imaging provide superior short-term or long-term clinical outcomes, more favorable patient-reported outcomes, or more consistent clinical treatment decisions affecting tooth prognosis (as measured by defect fill, improvements in bone anatomy, mobility patterns, and ultimate tooth survival)?

Inclusion Criteria

  • Adult humans with periodontitis
  • CBCT for diagnosis of periodontitis
  • Alternate modality to test validity of CBCT
  • Qualitative measurement of accuracy of CBCT

Exclusion Criteria

  • Non-English published studies
  • In-vitro, ex vivo, animal studies, editorial letters, reviews and case reports

Results:

  • Twelve articles included
    • 6 studies assessed the accuracy of CBCT for detection of Alveolar bone
    • 6 studies assessed the application of CBCT for diagnosis of furcation involvement
  • Periapical radiographs have better image quality than CBCT including contrast, clarity and detail
  • Boney defects comparing CBCT and Intraoral radiographs
    • Intrabonyand furcation defects were the two most commonly discussed
  • Diagnostic aspects of intrabonyand furcation defects can be improved via the use of CBCT
  • Limited evidence supported the use of CBCT improving the execution of therapy for both types of defects.
  • lack of literature to support the use of CBCT imaging for superior short-term or long-term clinical outcomes.
  • None of the literature reported patient-reported outcomes when CBCT imaging was used.

Conclusion: Routine use of CBCT for diagnosis and treatment of moderate-to -severe periodontitis does not appear to be warranted for the amount it cost and the radiation exposure. This may be a good option when the cost and radiation have both decreased.


Topic: Radiographs

Author: Mandelaris GA

Title: American Academy of Periodontology Best Evidence Consensus Statement on Selected Oral Applications for Cone-Beam Computed Tomography

Source: J Periodontol. 2017 Oct;88(10):939-945

Type: Consensus paper

Keywords: Cone-beam computed tomography; consensus; dental implants; orthodontics; periodontal disease; radiation exposure

Purpose: Consensus statement on selected oral applications for CBCT

Discussion:

Benefits of CBCT

  • Offersincreased diagnostic accuracy when compared to 2D digital diagnostic data
  • CBT imaging can be used as a communication tooth with pts and with other dental-medical colleagues involved in complex treatment planning cases

Limitations of CBCT

  • Limited evidence supports use of CBCT for detection of furcation and intrabony defects
  • Cost is also a drawback for CBCT

Potential Risks of CBCT

  • Unknown long-term radiation hazards of effective dose accumulation

Question 1: Should CBCT replace 2-D radiographic analysis of regional anatomy in the surgical management of pts requiring dental implants?

  • Current evidence supports the use of CBCT for the following:
  • Evaluation of root morphology and associated pathology for extractions and reconstruction
  • Location of relevant anatomic structures and their relation to implant placement
  • Sinus grafting pre-implant evaluation
  • Evaluation of autogenous bone donor sites
  • Fabrication of static surgical guides and dynamic
  • Navigation of implant placement
  • Post-bone augmentation implant planning
  • Complications with previously placed implants
  • Team communication with implant restorative colleagues

Question 2: Is CBCT imaging useful in determining risk to periodontal structures in patients requiring tooth movement?

  • Expert opinion suggests that CBCT may be useful in the management of patients requiring periodontal-ortho therapy in the following scenarios:
  • When the orthodontic patient is skeletally mature and presents with a malocclusion requiring fixed orthodontic appliances for decompensation
  • When the orthodontic patient has a thin dentoalveolar phenotype and dentoalveolar bone deficiencies are suspected
  • When the malocclusion patient requires advanced tooth movement and there is increased risk for positioning the roots outside of the orthodontic boundary conditions
  • When the orthodontic patient is skeletally immature and requires an interdisciplinary approach to treatment (i.e., periodontal-orthodontic-restorative ormulti-specialist care)
  • When the orthodontic patient presents with concomitant mucogingival deformities (recession)
  • When the patient presents with other specific treatment considerations requiring more global analysis (e.g., TMJ disorders, dentofacial disharmonies requiring orthodontic- periodontal-orthognathic approaches for management, congenitally missing teeth, or requirement for skeletal anchorage)

Question 3: Does CBCT imaging add clinical value in diagnostic assessment and treatment planning for the management of periodontitis?

  • Current evidence supports the use of 2D FMX in addition to clinical probing parameters as the gold standards for comprehensively evaluating periodontal structures.
  • Expert opinion suggests that CBCT may be useful in the management of patients with periodontitis according to the following scenarios:
  • When an advanced furcation lesion has been detected and dental implants are being considered as an alternative treatment option
  • When advanced bone loss has encroached on an- atomic structures, such as sinus cavities or the inferior alveolar nerve
  • When there is a questionable root fracture, root re- sorption, or periodontal-endodontic lesion present that could not be identified by 2D imaging and/or clinical evaluation
  • In the retreatment of cases that don’t respond favorably to localized periodontal therapy
  • To enhance the diagnosis and management of peri-implantitis when determined necessary

 

Topic: CBCT

Author: Tyndall, D.A., Price, J.B., Tetradis, S., Ganz, S.D., Hildebolt, C., Scarfe, W.

Title: Position statement of the American Academy of Oral and Maxillofacial Radiology on selection criteria for the use of radiology in dental implantology with emphasis on cone beam computed tomography

Source: Oral Surg Oral Med Oral Pathol Oral Radiol 2012 ;113:817-826

DOI: 10.1016/j.oooo.2012.03.005

Type: Position statement

Keywords: Implantology, radiology, cone beam computed tomography

Purpose: To summarize current knowledge about maxillofacial imaging (with emphasis on CBCT) for dental, endosseous-implant therapy and to provide up-to-date radiographic selection criteria for dental implantology.

Discussion:

Clinical considerations in selection criteria for dental implantology: Proper diagnosis and radiographic examination is important to the long-term success of a dental implant, with particular emphasis on a prosthetically driven approach.

Anatomic considerations: The maxillary anterior region (the esthetic zone) presents both surgical and prosthetic implant-assessment complexities. Decrease in the height and/or width of the alveolar process and the development of a labial concavity often necessitate bone augmentation. The anterior maxilla available bone is limited by:

  • The floor of the nose
  • The nasopalatine canal
  • The anterior extension of the maxillary sinus

The maxillary posterior region has the lowest bone density and the highest implant failure rate. The available residual alveolar ridge in the posterior, maxillary molar region is limited by the floor of the maxillary sinus.

In the mandible, the anterior region is susceptible to hemorrhage or neuroscensory disturbance if anatomy is not respected. In the posterior mandible, there are several anatomic structures that can compromise prosthetically driven, dental-implant placement.

  • The lingual concavity (submandibular gland fossa, submandibular fossa) below the mylohyoid ridge
  • the inferior alveolar (mandibular) canal

Imaging strategies: Clinicians commonly use 2 or more examinations. Each examination has specific indications, advantages, and disadvantages. A perfect imaging examination for dental-implant treatment planning does not exist.

Intraoral radiography: Periapical intraoral radiography provides images of limited dentoalveolar regions. These images have excellent spatial and contrast resolution with minimal distortions. The technique is the most widely available, inexpensive, and most common initial dental radiographic examination for implant-site assessment. The technique, however, is highly operator dependent and requires a moderate level of patient compliance to provide images with minimal geometrical distortions.

Cephalometic radiography:

Rotational panoramic radiography: This is the most commonly used extraoral imaging modality in implant dentistry. Panoramic radiography is commonly available, is relatively low cost, provides information on both dental arches, and is useful in the initial diagnostic phase of implant planning.

Cross-sectional imaging techniques: Cross-sectional images can be produced with conventional tomography, panoramic-based scanography and tomography, CBCT, and computed tomography (CT). Tomographic techniques produce multiple, contiguous image sections (slices) with minimal distortions, and uniform thicknesses and magnifications. In addition, images can be reconstructed such that they are perpendicular to each other. The main advantage of these images for implant dentistry is that they minimize or eliminate anatomic superimposition. Image sections perpendicular to the long axis of the region (object) of interest (e.g., the mandibular arch) are referred to as cross-sectional trans-axial images. Cross-sectional images provide optimal accuracy for visualizing the bony architecture of the jaws.

Conventional tomography: Unimodal machines capable of conventional tomography for the assessment of implant sites gained increasing popularity throughout the 1980s and 1990s. In conventional tomography, the x-ray source and the receptor move in synchrony and in opposite directions to each other about a fixed fulcrum, and this results in the blurring of structures outside the image plane, which is at the level of the fulcrum. A limitation of this technique is that it produces images of limited regions (a few teeth) of a single dental arch.

Panoramic-based tomography: Although this technique can be helpful in preliminary evaluations of specific implant sites, the technique is time-consuming and multiple inter- or intra-arch implant site assessments require multiple exposures.

Computed tomography: Data acquisition in CT has evolved over the past 4 decades with 4 generations of CT scanners. The most advanced systems use fan-beam radiation and multiple detector arrays. Usually, one source of fan-beam radiation is used. The user makes selections to define the spatial resolution, field of view (FOV), and image sharpness. As the object being scanned is translated through the CT scanner, the object attenuates the x-ray beam, and the attenuated x-ray beam data are collected by detector arrays. From the volume of data that is collected, mathematical formulas are used to recon- struct volumetric and/or multiplanar images. New techniques are being introduced for exposure reductions with the use of CT. CT is relatively expensive and usually available in hospitals and medical imaging centers only.

Cone beam computed tomography: CBCT differs from CT in that it uses a single x-ray source that produces a cone beam of radiation (rather than a fan beam, as with CT). CBCT imaging is performed using a rotating platform to which the x-ray source and detector are fixed. The x-ray source and detector rotate around the object being scanned and multiple, sequential, planar projection images are acquired in an arc of 180° or greater and are mathematically reconstructed into a volumetric dataset. Although CBCT images have high spatial resolution, the data from which images are created contains considerable noise caused by scattered radiation.

Magnetic resonance imaging: The limitations of these images for dental-implant imaging are the increased imaging scan times, dentists’ unfamiliarity with MR images, and higher costs. For dental- implant imaging, MR images are of research and educational interest only.

Radiation dose considerations: Appropriate selection criteria must be used with the minimum radiation exposures that result in images of acceptable diagnostic qualities. This concept is known as ALARA (as low as reasonably achievable). Although CBCT usually results in lower doses than CT, both result in substantially higher doses to patients than do other dental-implant imaging methods. With both CT and CBCT, there is wide variability in doses among different systems and among different imaging protocols (slice thickness, FOV, mAs, kVp, scan time).

Principles of imaging for dental-implant assessment: Images should have appropriate diagnostic quality and not contain artifacts that compromise anatomic-structure assessments. Images should extend be- yond the immediate area of interest to include areas that could be affected by implant placements.

Conclusions: The AAOMR recommends

The decision to perform a CBCT examination must be clinically justified and based on professional judgment (that is, the judgment of the clinician is that the use of CBCT will potentially provide information needed for prosthetic treatment planning, implant selection, and/or surgical placement). The CBCT imaging protocol should include the smallest FOV necessary and available and optimize exposure parameters. For periodic, postoperative implant monitoring, periapical and, in some cases, panoramic images provide adequate imaging. All CBCT volumes, regardless of clinical application, should be systematically evaluated for signs of abnormalities. This can be performed by the referring dentist or specialist (such as an oral and maxillofacial radiologist) competent in the interpretation of CBCT.

Topic: radiographic reliability

Authors: Benn DK. J.

Title: A review of the reliability of radiographic measurements in estimating alveolar bone changes.

Source: Clin. Periodontol. 17:14-21, 1990.

DOI: 10.1111/j.1600-051X.1990.tb01041.x

Type: review

Keywords: radiographs; periodontal disease’ measurement error; rate of bone loss; monitoring systems.

P: to identify those factors which influence the accuracy of radiographic measurement, to calculate the range of time required to detect bone loss with different measurement errors and intervals, to examine the clinical applications for monitoring bone changes.

D:

Factors affecting a radiographic monitoring system:

  • Irradiation geometry
    • Unstandardized film positioning and root anatomy.
    • Ideal radiograph would contain an excellent view of the interdental crest including the periodontal membrane spaces
  • Sensing devices: AgBr films, xenoradiography, solid state sensing devices
  • Film technique: extra oral (Pano) vs. intraoral x-rays.
    • 4mm of crestal bone loss – use a single horizontal BW
    • more extensive bone loss – use vertical BWs
  • Reliability of references: CEJ to Crest
  • Intervals for routine RG examination:
    • A baseline set of BWs were taken at 12 yo (time of peak caries) and a further set 1 year later, rapid bone loss or caries progression should be detectable.
  • Possible solutions:
    • Standardized film holders are needed to reduce irradiation geometry errors in images.

C: the current measurement techniques are insufficiently sensitive to measure true bone loss until at least 1mm BL has occurred. Radiography is an accurate method for longitudinal monitor of alveolar bone loss. However, it will not provide evidence of current disease. More accurate methods need to be developed.

Topic: Radiographs

Author: Jeffcoat MK.

Title: Radiographic methods for the detection of progressive alveolar bone loss.

Source: J Periodontol 63: (Suppl 4) 367-372, 1992

Type: Review

Rating: Good

Keywords: Bone resorption/diagnosis; bone/radiograph; periodontal disease/diagnosis; radiography, digital subtraction; periodontitis/diagnosis; periodontal attachment

P: To review radiographic techniques for the assessment of periodontal disease progression. Also to address the relationship of bone loss as detected by digital subtraction radiography and periodontal disease progression as measured with a sensitive automated periodontal probe.

M&M: 30 patients with untreated periodontal disease & pockets of > 5mm at the experimental site, and 8 healthy patients without bone loss or periodontal disease (any patient with systemic disease was excluded). This study looked at 5 posterior sites in each patient using an automated probe to measure attachment levels at 0,2,4,6 months & DSR to detect progressive bone loss at 0 and 6 months. The Automated probe-instrument retracts when a force of 35gm felt at base of pocket. Standardized radiographs were taken at baseline and 6 months.

R:

-No site in a control patient lost bone or attachment over the 6 months of the study.

-According to DSR, 38% of sites in 76% of the patients were considered to have active bone loss.

-When probing attachment level was assessed, 35% of sites were considered active, observed in 79% of patients.

-A concordance of the results of the subtraction radiography and automated probing attachment level examinations was found in 82.1% of sites, showing these patients had active loss of attachment.

C: There is a high degree of concordance between sites of disease activity detected by automated probing & digital radiography.

Topic: Radiography

Authors: Tugnait A, Clerehugh V, Hirschmann PN ARTICLE

Title: The usefulness of radiographs in diagnosis and management of periodontal diseases: a review

Source: J Dent 28:219-226, 2000

Type: Review

Rating: Good

Keywords: dental radiography, periodontal disease, diagnosis, management, clinical effectiveness

P: To review the periodontically significant information obtainable from conventional radiographs and the stages during patient management when this information may assist care.

C: Role of radiographs in the assessment and diagnosis of a periodontal condition: Radiographs provide information about the bone levels and pattern of bone loss that cannot be gained through clinical examination. Position of bony crest, horizontal or vertical bone loss, and location of vertical defects can be identified. Subjective information on bone quality can be gained as well as crown to root ratio. Distance from the CEJ to the bone crest between 0.4-2mm (according to some studies even 3mm) is considered normal with no clinical attachment loss, but clinical estimation of attachment loss is more accurate and precedes radiographic bone loss. Furcation involvements, calculus deposits and anatomical defects such as enamel pearls can also be seen in radiographic images. Bone loss is underestimated in initial periodontal disease, relatively accurate in moderate disease, and overestimated in the advanced stages. The addition of bite wings to panoramic and periapical radiographs increases the detection rate of vertical and furcation defects. Radiographs are highly specific but of limited sensitivity, therefore they are not suitable means of detecting calculus. Radiation risk is lower for a panorex than a full mouth periapical series.

Role of radiographs in management of periodontal diseases: Radiographs are useful in all phases of periodontal treatment. They provide information in the initial therapy (bone loss, determination of hopeless teeth, apical status, and status of restorations) as well as before surgical therapy. In supportive therapy there are no specific intervals for repetition of the radiographs. They depend on the type of periodontal disease (aggressive, chronic) and on the clinical findings during the maintenance visits.

Value added by radiographs: Literature is limited in this field. Treatment decisions are altered when radiographs are taken into account with the clinical findings mostly in relation to extractions, restorative and prosthodontic treatment (43, 40 and 31% respectively) and less in periodontal treatment (15.6%).

B: Conventional radiographs provide information relevant to the diagnosis and management of the periodontal diseases. This information assists in the overall management of the patients. It is less obvious to what extent radiographs truly influence the treatment provided and its ultimate success. It is possible that clinical assessments alone are appropriate for some groups of patients, with radiographs used as a second phase diagnostic test in specific situations or sites rather than routinely due to the risk of exposure to unneeded radiation.

Topic: Radiographic Guidelines

Authors: Kim IH, Mupparapu M

Title: Dental radiographic guidelines: a review.

Source: Quintessence Int. 2009 May;40(5):389-98.
Type: Review

Rating: Good

Keywords: Guidelines, dental radiographic
P: To review history of dental radiographic guidelines and rationale for existence. The literature was also reviewed for its utilization and the North American and European guidelines were compared.

D:

  • FDA advised in 1985 to have nonemergency radiographic exam of teeth and surrounding structures based off of the presence of suspected lesions and the likelihood of disease. Updates since that time (FDA and ADA guidelines from 1997, 1999, and 2004) have not had many changes.
  • The ADA guidelines recommend that radiographs be taken to achieve images of high diagnostic quality in a short time with a minimal dose of radiation. The foundation of this is the ALARA principle (as low as reasonably achievable).
  • Existing guidelines do recommend taking radiographs on pregnant patients with careful adherence to selection criteria as it is known that dental disease left untreated during pregnancy can be problematic for mother and fetus.
  • It is also recommended to take XR on patients undergoing head and neck radiation without any special precautions.
  • XR are traditionally prescribed to evaluate caries and periodontal condition, but guidelines state they can also be taken to screen for other orofacial and clinical conditions, to evaluate treatment options, to assess pathology, to evaluate restorative and endodontic needs, and to use in implant placement or evaluation.
  • At this time, there are neither proposed or published guidelines for the use of CBCT in dentistry.
  • There is a 2007 International Commission on Radiologic Protection that takes into account different types of CT scans and possible sequelae of these radiographic images.