1. Interpretation of Periodontal Disease

2. Components of the Periodontium
Gingiva
Alveolar Bone
Periodontal Ligament
Cementum

3. Description of the Periodontium
Lamina dura
Lamina dura appears as a dense radiopaque line in healthy teeth.
Alveolar crest
This is about 1.5 to 2 mm apical to the CEJ of adjacent healthy teeth.
In anterior teeth, the alveolar crest is pointed and sharp and appears to be very radiopaque.
In posterior teeth, the alveolar crest appears flat and smooth, and parallel to a line between adjacent cementoenamel junctions.
It appears a little less radiopaque than in anterior teeth.
Periodontal ligament space
This appears as a thin radiolucent line between the root of the teeth and the lamina dura.
It is continuous around the root structure and of uniform thickness in healthy teeth.
The periodontium refers to the tissues that invest and support the teeth.

4. Description of Periodontal Disease
Periodontal disease is a group of diseases that affect the tissue around teeth.
May range from superficial inflammation of gingiva to destruction of supporting bone and periodontal ligament.
The gingiva appears swollen, red, and bleeding, with soft tissue pocket formation.
The image appearance is different.
The alveolar crest appears indistinct.
Bone loss is seen.
What should normal, healthy gum tissue look like?

5. Detection of Periodontal Disease
Clinical Examination
Dental Image Examination
Dental images must be used in conjunction with a clinical examination.

6. Dental Image Examination
This provides an overview of the amount of bone present.
Indicates the pattern, distribution, and severity of bone loss.
The periapical image is the image of choice for the evaluation of periodontal disease.
The vertical bite-wing image can be used to examine bone levels in the mouth.
The horizontal bite-wing has limited value in the detection of periodontal disease.
The panoramic image has little diagnostic value in the detection of periodontal disease.
The paralleling technique accurately records the relationship of the height of the crestal bone to the tooth root.

7. Radiographic Examination
Images alone cannot be used to diagnose periodontal disease.
They do not provide information about the condition of soft tissue or early bone changes.
They are two-dimensional representations of three-dimensional objects.
Buccal and lingual areas may be difficult to evaluate.
Bone loss may be difficult to detect in furcation areas.

8. Interpretation of Periodontal Disease on Dental Images
Bone Loss
Classification of Periodontal Disease
Predisposing Factors

9. Interpretation of Periodontal Disease on Dental Images
All images should be
Evaluated for bone loss
Examined for other predisposing factors that may contribute to periodontal disease

10. Bone Loss
Can be estimated as the difference between the physiologic bone level and the height of remaining bone
It can be described in terms of the pattern, distribution, and severity of loss
A radiograph allows the dental professional to view the amount of bone remaining rather than the amount of bone lost.

11. Pattern Described as either horizontal or vertical
Horizontal bone loss
The loss occurs in a plane parallel to the CEJs of adjacent teeth
Vertical bone loss
The loss does not occur in a plane parallel to the CEJs of adjacent teeth
Vertical bone loss is also referred to as angular bone loss.

12. Distribution Described as localized or generalized Localized
Occurs in isolated areas
Generalized
Occurs evenly throughout the dental arches
Localized has less than 30% of the sites involved.
Generalized has more than 30% of the sites involved and occurs evenly throughout the dental arches.

13. Severity Can be classified as mild, moderate, or severe
Mild bone loss: crestal changes
Moderate bone loss: bone loss of 10% to 33%
Severe bone loss: bone loss of 33% or more
Measured by the clinical attachment loss, distance in mm from the CEJ to the base of the sulcus or periodontal pocket.
Measured by a calibrated periodontal probe.

14. Classification of Periodontal Disease
Based on the amount of bone loss, periodontal disease can be classified as ADA case
Type I: gingivitis
Type II: early periodontitis
Type III: moderate periodontitis
Type IV: advanced periodontitis
Each disease type has a specific radiographic appearance.
Radiographs can also be used to detect the contributing factors of periodontal disease, such as calculus and defective restorations.

15. ADA Case Type I Gingivitis No associated bone loss
No change is seen in bone when viewed on a dental image
The crestal lamina dura is present, and the alveolar crest is approximately 1 to 2 mm apical to the CEJ.
Bleeding may or may not be present.
Only the gingival tissues are affected.

16. ADA Case Type II Early periodontitis
Associated with mild crestal changes
The lamina dura becomes unclear and fuzzy and no longer appears to be a continuous radiopaque line.
Horizontal bone loss is seen more often.
Bleeding may occur with probing, pocket depths resulting from attachment loss may be present, and localized areas of recession may also be seen.

17. ADA Case Type III Moderate periodontitis
Is associated with 10% to 33% bone loss.
The pattern may be horizontal or vertical, the distribution may be localized or generalized.
Furcation involvement may be seen.
The alveolar bone level is approximately 4 to 6 mm apical to the CEJs of adjacent teeth.
When the bone in the furcation is destroyed, a radiolucent area is evident on the dental image.
Clinically, pocketing and attachment loss is evident up to 6 mm.
Recession, furcation involvement areas, and slight mobility may also be present.

18. ADA Case Type IV Advanced periodontitis
Associated with more severe bone loss (33% or more)
May be vertical, and the alveolar bone level is 6 mm or great from the CEJ.
Furcation involvement is readily viewed on posterior images.

19. Predisposing Factors
Predisposing factors and local irritants may contribute to periodontal disease
Elimination is important in the management and treatment of periodontal disease
Dental images aid in detection of irritants such as
Calculus
Defective restorations
The effects of certain medications, tobacco use, and conditions such as diabetes are all considered risk factors for periodontal disease.

20. Calculus Results from the mineralization of plaque
Appears white or light on a dental radiograph
Most often appears as a pointed or irregular radiopaque projection extending from proximal root surfaces
May also appear as a
Ring-like opacity
A nodular image projection
A smooth opacity on a root surface
Stonelike concretion that forms on the crowns and roots of teeth due to the calcification of bacterial plaque.

21. Defective Restorations
Faulty restorations may act as food traps and lead to the accumulation of food debris and bacteria
They may be detected both clinically and on dental images
Dental images may allow identification of restorations with
Open or light contacts
Poor contour
Uneven marginal ridges
Overhangs
Inadequate margins