Alveolar Bone

The alveolar process is the portion of the mandible and maxilla that contains the teeth and the alveoli in which they are suspended

The alveolar process rests on basal bone

The alveolar bone proper lines the alveolus (or ‘tooth socket’) which is contained within the alveolar process

It is composed of a thin plate of cortical bone with numerous perforations (‘cribriform plate’) that allow the passage of blood vessels between the bone marrow spaces and the periodontal ligament

The coronal rim of the alveolar bone forms the alveolar crest

Radiographically, normal bone patterns include the following:

Crest of alveolar bone should be 1-2mm apical to CEJ

The contour of alveolar bone should follow the contour of CEJ

Intact lamina dura

Periodontal ligament space should be visible and uniform

Radiographic findings of bony destruction:

Horizontal or vertical bone loss

Horizontal loss indicated by >2mm reduction of bone height

Vertical bone loss is angular

Change in furcation involvement

Lamina dura becomes less distinct

Bony Defect/Pocket:

Suprabony defect

Base of pocket is coronal to the alveolar bone; all gingival pockets

Intrabony defect

The base of pocket is apical to crest of alveolar bone

Board Clarification: To understand the terminology better, remember ‘intra’ means within—intrabony defects occur within bone. ‘Supra’ denotes above—suprabony defects occur above the alveolar bone crest. When periodontal infection results in the development of an intrabony defect, the base of the pocket is apical to a wall of bone. By contrast, when a suprabony ‘pocket’ develops, the base of the defect is coronal to the crest and is located above the bone