Periodontal Disease- Patterns Of Bone Loss

Although periodontal disease is an infectious disease of the gingival tissue, changes in the bone are
crucial because bone destruction eventually leads to tooth loss.
The height and density of the alveolar bone is maintained by a balance between bone formation and bone
destruction

DIFFERENT PATTERNS OF BONE DEFECTS SEEN IN PERIODONTAL DISEASE

Different types of bone deformities can result from periodontal disease. They can be easily detected on
radiograph, but careful probing and surgical exposure of the areas are needed to confirm the exact
dimensions.

Horizontal Bone Loss
It is the most common bone loss pattern seen in periodontitis.
The bone level is reduced, but the bony margins remain perpendicular to the tooth surface.
The facial and lingual bony plates, and the interdental septa are affected but not necessarily to an equal
degree around the same tooth.

Vertical or angular defects
They occur in an oblique direction leaving a trough along side the root.
The base of the defect is located apical to the surrounding bone.
They are classified on the basis of the no. of osseous walls absent.
They are called as 1,2 3 walled defects.
The 3 walled angular defect is also called a hemiseptal defect which indicates the presence of 1 bony
wall. Such defects ensure poor prognosis.

Osseous Craters
These are concavities in the crest of the interdental bone confined within the facial and lingual walls.
Commonly seen in mandibular posterior segments.

Bulbous bone contours
These are bony enlargments caused by exostoses, adaptation ta funtion by tressing bone formation,
found more frequently in the maxilla.

Reversed architecture
Produced by loss of intedental bones including facial and lingual plates and excluding loss of radicular
bones
This leads to reversing the bony architecture.
Commonly seen in the maxilla.

Ledges
These are plateau like bony margins caused by resorption of thickend bony plates.

Furcation involvement
This refers to the invasion of the bifurcation and trifurcation of multi rooted teeth by periodontal disease.
Furcation involvements can be classified as GradesI,II,III,IV depending on the amount of tissue
destruction.