1. 25
The Use of Radiographs in the Evaluation of Periodontal Diseases

2. Objectives Define the key words.
List the uses of radiographs in the assessment of periodontal diseases.
Differentiate between horizontal and vertical bone loss.
Identify three local contributing factors for periodontal disease that radiographs can help locate.

3. Objectives
Explain how imaging anatomical configurations aids in the prognosis of periodontally involved teeth.
List the limitations of radiographs in the assessment of periodontal diseases.
Recognize the role vertical and horizontal angulations play in imaging periodontal diseases.

4. Objectives
Use the appropriate radiographic techniques to best detect and evaluate periodontal diseases.
Describe the radiographic appearance of the normal periodontium.
List four American Academy of Periodontology disease classification case types and describe their radiographic appearance.

5. Key Words Alveolar (crestal) bone Calculus
Cementoenamel junction (CEJ)
Furcation involvement
Generalized bone loss
Gingivitis
Horizontal bone loss
Interdental septa

6. Key Words Lamina dura Local contributing factor Localized bone loss
Occlusal trauma
Pathogens
Periodontal diseases

7. Key Words Periodontal ligament space Periodontitis Periodontium
Triangulation
Vertical (angular) bone loss
Vertical bitewing series

8. Introduction
Dental radiographs play a key role in the diagnosis, prognosis, management, and evaluation of periodontal diseases.
Properly exposed and meticulously processed radiographs are invaluable aids in the diagnosis of periodontal diseases.

9. Introduction
To get the most diagnostic information from radiographs taken to image periodontal status, radiographers should have an extensive knowledge of the radiographic techniques that will produce quality images.

10. Radiographic Appearance of Periodontal Diseases
Gingivitis
Periodontitis

11. Radiographic Examination
Uses
Limitations

12. BOX 25-1 Periodontal Bone Changes Recorded by Radiographs

13. Figure 25-1 Drawing illustrating horizontal bone loss
Figure Drawing illustrating horizontal bone loss. (A) Normal (physiologic) level of bone (alveolar bone parallel to the cementoenamel junction) and (B) Bone level of patient with periodontal disease. Horizontal bone loss is the difference between (A) and (B) (shaded area).

14. Figure 25-2 Horizontal bone loss
Figure Horizontal bone loss. Arrows show bone level of patient with periodontal disease. Note that the level of bone loss is parallel to an imaginary line drawn between the cementoenamel junctions of the adjacent teeth.

15. Figure 25-3 Drawing illustrating vertical bone loss
Figure Drawing illustrating vertical bone loss. Vertical bone loss appears angular where the resorption is greater on the side of one tooth than on the side of the adjacent tooth.

16. Figure 25-4 Vertical bone loss
Figure Vertical bone loss. Arrows show bone level of patient with periodontal disease.

17. Figure 25-5 Comparison of horizontal and verical bone loss
Figure Comparison of horizontal and verical bone loss. Use the CEJ of adjacent teeth as a guideline. (1) Horizontal bone loss. (2) Vertical bone loss.

18. Figure 25-6 Furcation involvement
Figure Furcation involvement. Note the radiolucency in between the roots of these multirooted teeth.

19. Figure 25-7 Local contributing factors
Figure Local contributing factors. Calculus (arrow) and amalgam overhang (circled) are likely to collect bacterial pathogens that can contribute to the progression of periodontal diseases.

20. Figure 25-8 Calculus. (1) large deposits around the necks of the teeth
Figure Calculus. (1) large deposits around the necks of the teeth. (2) Height of alveolar bone remaining as a result of periodontal disease.

21. Figure 25-9 Triangulation
Figure Triangulation. Widening of the periodontal ligament space indicative of occlusal trauma.

22. Figure 25-10 Root length and root-to-crown ratio
Figure Root length and root-to-crown ratio. Although the bone loss observed on this radiograph is significant, the longer than normal, dilacerated root improves the prognosis for the canine.

23. Figure Comparsion of bitewing and periapcial radiographs imaging the periodontium. (A) Vertical bitewing. (B) Horizontal bitewing. (C) Periapical.

24. Figure 25-12 Correct and incorrect vertical angulation
Figure Correct and incorrect vertical angulation. (A) Correct vertical angulation accurately records crestal bone indicating no bone loss between the mandibular first and second molars. (B) Incorrect vertical angulation produces a radiolucent, cupping-out appearance of the lamina dura falsely indicating bone loss between these same teeth. (Thomson, E. M., & Tolle, S. L. (1994). A practical guide for using radiographs in the assessment of periodontal diseases. Part 2: Interpretation and future advances. Journal of Practical Hygiene, 3(2), 12. Permission from Montage Media.)

25. Figure 25-13 Correct and incorrect vertical angulation
Figure Correct and incorrect vertical angulation. (A) Correct vertical angulation accurately records crestal bone indicating bone loss mesial and distal to the maxillary first molar,. (B) Incorrect vertical angulation produces a false appearance to the level of bone in these same areas. (Thomson, E. M., & Tolle, S. L. (1994). A practical guide for using radiographs in the assessment of periodontal diseases. Part 2: Interpretation and future advances. Journal of Practical Hygiene, 3(2), 12. Permission from Montage Media.)

26. Figure 25-14 Example of varying horizontal angulation
Figure Example of varying horizontal angulation. (A) Correct horizontal angulation, but image does not reveal the vertical (angular) defect on the mesial of the maxillary first molar. (B). Slightly varied horizontal angulation of the same region now reveals the vertical bony defect. (Thomson, E. M., & Tolle, S. L. (1994). A practical guide for using radiographs in the assessment of periodontal diseases. Part 2: Interpretation and future advances. Journal of Practical Hygiene, 3(2), 13. Permission from Montage Media.)

27. TABLE 25-1 American Academy of Periodontal Disease Classification

28. PROCEDURE 25-1 Radiographic interpretation for periodontal disease

29. Figure 25-15 Drawing illustrating Case Type I: Gingivitis
Figure Drawing illustrating Case Type I: Gingivitis. Alveolar crest located 1.5 to 2.0 mm apical to the cementoenamel junctions (CEJ) of the teeth.

30. Figure 25-16 Case Type I: Gingivitis-anterior region
Figure Case Type I: Gingivitis-anterior region. Note the normal pointed radiopaque appearance of the lamina dura and thin radiolucent line of the periodontal ligament space.

31. Figure 25-17 Case Type I: Gingivitis-posterior region
Figure Case Type I: Gingivitis-posterior region. Note the normal radiopaque flat appearance of the lamina dura and thin radiolucent line of the periodontal ligament space.

32. Figure 25-18 Drawing illustrating Case Type II: Slight Chronic Periodontitis.

33. Figure Case Type II: Slight Chronic Periodontitisposterior region. Note the slight radiolucent cupping-out of the lamina dura, especially visible between the mandibular first and second molars. Radiopaque calculus is visible on the proximal surfaces of the teeth.

34. Figure Case Type II: Slight Chronic Periodontitis-anterior region. Note the blunting of the lamina dura and slight radiolucent widening of the periodontal ligament space. Slightly radiopaque calculus is visible.

35. Figure Case Type II: Slight Chronic Periodontitis-anterior region. Note the blunting of the lamina dura and slight radiolucent widening of the periodontal ligament space. Slightly radiopaque calculus is visible.

36. Figure Case Type III: Moderate Chronic or Aggressive Periodontitis-anterior region. Note the 30–50 percent bone level resorption.

37. Figure Case Type III: Moderate Chronic or Aggressive Periodontitis-posterior region. Note the 30–50 percent bone level resorption and radiolucency in the furca of the mandibular molars indicating furcation involvement.

38. Figure 25-24 Drawing illustrating Case Type IV: Advanced Chronic or Aggressive Periodontitis.

39. Figure Case Type IV: Advanced Chronic or Aggressive Periodontitis-anterior region. Note the 50 percent or greater bone level resorption.

40. Figure Case Type IV: Advanced Chronic or Aggressive Periodontitis-posterior region. Note the 50 percent or greater bone level resorption and obvious furcation involvement.

41. Review: Chapter Summary
Periodontal diseases are diseases that affect both soft tissues (gingivitis) and bone around the teeth (periodontitis).

42. Review: Chapter Summary
The uses of radiographs in the evaluation and treatment of periodontal diseases include imaging the supporting bone, locating local contributing factors, imaging anatomical configurations; evaluating prognosis and treatment intervention needs; and serving as a baseline for identifying and documenting the progression of the disease and the results of treatment.

43. Recall: Study Questions
General
Chapter Review

44. Reflect: Case Study
Describe what radiographic changes in the periodontium you would expect to observe on a seven-image series of vertical bitewings on the following patients classified according to the American Academy of Periodontology Disease Classification:

45. Reflect: Case Study Case Type I: Gingivitis
Case Type II: Slight Chronic Periodontitis
Case Type III: Moderate Chronic or Aggressive Periodontitis
Case Type IV: Advanced Chronic or Aggressive Periodontitis

46. Relate: Laboratory Application
Proceed to Chapter 25, Laboratory Application, to complete this activity.