BONE DESTRUCTION PATTERNS IN

PERIODONTAL DISEASE

S. MANEESH AHAMEDROLL NO : 12FINAL YEAR PART 1

• INTRODUCTION• OSSEOUS DEFECTS• CLASSIFICATION OF OSSEOUS DEFECTS• HORIZONTAL BONE LOSS• VERTICAL/ANGULAR BONE LOSS - TYPES OF ANGULAR BONE LOSS• OSSEOUS CRATERS• BULBOUS BONY CONTOURS•LEDGES•FURCATION INVOLVEMENT - CLASSIFICATION OF FURCATION INVOLVEMENT•CONCLUSION•BIBLIOGRAPHY

CONTENTS

•Extension of inflammation from the marginal gingiva into the supporting periodontal tissues marks the transition from gingivitis to periodontitis.

INTRODUCTION

•Periodontal disease alters the morphologic features of the bone in addition to reducing bone height

•Understanding of the nature and pathogenesis of these alterations is essential for effective diagnosis and treatment plan.

•Level of bone is the consequence of past pathologic experiences.

OSSEOUS DEFECTS•Different types of bone deformities can result from periodontal disease.

•These usually occur in adults but have also been reported in human skulls with deciduous dentitions.

•Their presence may be identified in radiographs, but careful probing and surgical exposure of the areas are required to determine their exact conformation.

CLASSIFICATION ACCORDING TO GLICKMAN (1964)

1. Osseous craters2. Hemiseptal defects3. Infrabony defects4. Bulbous bone contours 5. Inconsistent margins and Ledges6. Reversed architecture

ACCORDING TO PRICHARD (1967)

He expanded Glickman’s classification by including furcation involvement, anatomic aberrations of alveolar process, exostoses & tori, dehisence & fenestrations.

ACCORDING TO GOLDMAN AND COHEN (1958)

Supra bony pocket Infra bony pocket > Infra bony defect 1. one walled defect 2. two walled defect 3. three walled defect 4.combined defect > Craters

Inter radicular defects > Horizontal defects (Glickman’s) 1. Class I 2. Class II 3. Class III > Vertical defects (Tarnow & Fletcher) 1. Sub-class A 2. Sub-class B 3. Sub-class C

•Most common pattern of bone loss

•Bone is reduced in such a way that the bone margin is approximately perpendicular to the teeth surface

•Interdental septa and facial and lingual plates of bone are affected, but necessarily to an equal degree around the same tooth.

HORIZONTAL BONE LOSS

VERTICAL OR ANGULAR DEFECTS•Vertical/ Angular defects occur in a oblique direction.

•This creates a hollowed-out trough in the bone alongside the root.

•The base of the defect is located apical to the surrounding bone.

•In most instances, angular defects have an accompanying intrabony periodontal pockets.

TYPES OF ANGULAR DEFECTS

Classified based on the number of osseous walls…. (Goldman & Cohen)

1. ONE WALLED DEFECTS

2. TWO WALLED DEFECTS

3. THREE WALLED DEFECTS

4. COMBINED OSSEOUS DEFECTS

A. THREE WALLED DEFECT

(INTRABONY DEFECT)

B. TWO WALLED DEFECT

C. ONE WALLED DEFECT

(HEMISEPTUM)

D. COMBINED OSSEOUS DEFECT

•Vertical defects occurring interdentally can generally be seen on the radiograph.

•Thick bony plates sometimes may obscure them.

•Angular defects of facial and lingual or palatal surfaces are not seen on radiographs

•Surgical exposure is the only way to determine the presence and configuration of vertical osseous defects

•Vertical defects increases with age.

•Approximately 60% of persons with interdental angular defects have only single defect.

•Radiographically detected defects appear most often on the distal and mesial surfaces

•However, three-wall defects are more frequently found on the mesial surfaces of upper and lower molars.

OSSEOUS CRATERS•Osseous craters are concavities in the crest of the interdental bone confined within the facial and lingual walls

•Craters have been found to make up about one-third of all defects and about two-thirds of all mandibular defects.

•They occur twice as often in posterior segments as in anterior segments.

Heights of facial and lingual crests of the crater: Equal in 85% cases Facial > Lingual in 6.5% Lingual > Facial in 6.5%

The high frequency of interdental craters have been attributed to:

1. The interdental area collects plaque and is difficult to clean

2. The normal flat or even slightly concave faciolingual shape of the interdental septum in lower molars may favor crater formation.

3. Vascular patterns from the gingiva to the centre of the crest may provide a pathway for inflammation.

BULBOUS BONE CONTOURS•Bulbous bone contours are bony enlargements caused by exostoses, adaptation to function, or buttressing bone formation.

•They are found more frequently in the maxilla than in the mandible.

•Exostoses are outgrowths of bone of varied size and shape. •The can occur as small nodules, large nodules, sharp ridges, spike like projections, or any combination of these.

•Bone formation occurs in an attempt to buttress bony trabaculae weakened by resorption.

•When it occurs within the jaw, it is termed as central buttressing bone formation.

•When it occurs in external surface, it is referred to as peripheral buttressing bone formation.

•The latter may cause bulging of the bone contour, termed as lipping, which some times accompanies the production of osseous craters and angular defects.

REVERSED ARCHITECTURE•They are produced by loss of interdental bone, including the facial plates, without concomitant loss of radicular bone.

•The normal architecture of bone is thus reversed

•These defects are more commonly seen in the maxilla

LEDGES•Ledges are plateau like bone margins caused by resorption of thickened bony plates

FURCATION INVOLVEMENT•The term Furcation involvement refers to the invasion of the bifurcation and trifurcation of multi-rooted teeth by periodontal disease.

•Denuded furcation may be visible clinically or covered by the wall of pocket.

•Extend of involvement is determined by exploration with a blunt probe, along with a simultaneous blast of warm air to facilitate visualization.

CLASSIFICATION CLASSIFICATION BY GLICKMAN -1958 (Horizontal)

Grade I - Incipient bone loss Grade II - Partial bone loss (cul-de-sac) Grade III - Total bone loss - through-and through Grade IV - Bone loss similar to grade III with gingival recession. exposing the furcation area.

CLASSIFICATION BY TARNOW & FLETCHER-1984 (vertical)

1. Sub-class A (0-3mm) 2. Sub-class B (4-6mm) 3. Sub-class C (>7mm)

•Microscopically, furcation exhibits no unique pathologic features.

•Furcation involvement is a stage of progressive periodontal disease and has its same etiology.

•The difficulty and some times impossibility of controlling plaque is responsible for the presence of lesions in this area.

•Trauma from occlusion has been suspected as a contributing etiologic factor in cases of furcation involvement with crater like or angular deformities in the bone especially when bone destruction is localized in one of the roots.

•Other factors that may play a role are: > presence of enamel projections into the furcation > Proximity of the furcation to the cementoenamel junction > Presence of accessory pulpal canals in the furcation area.

CONCLUSION Periodontal disease cause alteration in the morphologic pattern of the alveolar bone. They usually follow definite clinical or pathological patterns. A good understanding of the nature and pathogenesis of these alterations will help in effective diagnosis and treatment of the disease.

BIBLIOGRAPHY

• Carranza’s Clinical Periodontology 10th Edition•Clinical Periodontology an dental Implantology - Lindhe