The alveolus (plural: alveoli) is the specialized bony socket within the maxilla or mandible that houses and supports the root of each tooth. These precisely contoured cavities form the structural foundation of tooth anchorage, working in direct concert with the periodontal ligament and cementum to hold teeth securely in position.

Structure and Key Components

Each alveolus is composed of two bone layers and several anatomically distinct features:

• Cortical (compact) bone: the dense outer shell, visible on radiographs as the lamina dura — a bright white line that traces the contour of the root
• Cancellous (trabecular) bone: the spongy inner lattice that provides structural support while accommodating blood vessels and nerves
• Alveolar crest: the coronal rim of the socket, typically the first region to show bone loss in periodontal disease
• Cribriform plate: the perforated inner socket wall through which Sharpey’s fibers of the periodontal ligament embed into the bone

Clinical Significance

The condition of the alveolus is a direct indicator of periodontal health. In active periodontal disease, bacterial inflammation drives bone resorption that erodes alveolar walls — a process visible on radiographs as blunting of the alveolar crest and fading of the lamina dura. Unchecked, this resorption destroys the periodontal ligament attachment, causing progressive tooth mobility and, ultimately, tooth loss.

After an extraction, the empty alveolus undergoes a predictable healing sequence: clot formation, granulation tissue deposition, woven bone formation, and finally maturation into lamellar bone. Without intervention, this remodeling typically reduces ridge width by up to 50% within the first year. Socket preservation — packing the alveolus with bone graft material at the time of extraction — significantly limits dimensional loss and maintains a viable site for future dental implant placement.

Implant success depends entirely on alveolar bone volume and density, as osseointegration requires direct contact between the implant surface and living bone. Preserving a healthy alveolus from the outset remains the most reliable strategy for expanding long-term tooth replacement options.

Addressing periodontal disease early and choosing socket preservation when extractions are necessary are the most effective ways to protect the alveolus and maintain the jaw’s structural foundation for years to come.