The dental alveolar bone provides essential support for teeth within the oral cavity. This specialized bone is a component of the jawbones, specifically the maxilla in the upper jaw and the mandible in the lower jaw. Its integrity is closely linked to overall oral health, influencing chewing efficiency and facial aesthetics. Understanding its structure and function is key to maintaining a healthy smile.
Understanding the Dental Alveolar Bone
The dental alveolar bone is part of the jawbone that encases the tooth sockets, often referred to as alveoli. This specialized bone structure is distinct from the basal bone of the jaw, which lies beneath the root apices.
Alveolar bone includes both inorganic and organic materials. Approximately 67% of its weight is inorganic material, primarily calcium and phosphate, found as calcium hydroxyapatite crystals. The remaining 33% consists of organic material, mainly collagen and non-collagenous proteins, along with cellular components like osteoblasts, osteocytes, and osteoclasts. The alveolar bone also contains compact bone plates on its facial and lingual surfaces, and a central spongy or cancellous bone.
Key Roles of the Alveolar Bone
The primary function of the alveolar bone is to provide stable anchorage for the teeth. It forms the sockets that firmly hold each tooth in place. This bone works in conjunction with the periodontal ligament, a network of fibers that connect the tooth root to the bone, ensuring tooth stability.
Beyond anchoring teeth, the alveolar bone also distributes forces generated during chewing. It acts as a shock absorber, helping to dissipate occlusal forces and protect the teeth from excessive stress. The bone is dynamic and can remodel in response to these mechanical demands, adapting its structure to maintain dental health.
Common Issues Affecting the Alveolar Bone
Alveolar bone loss is a common problem, often resulting from periodontal disease, tooth extractions, or trauma. Periodontal disease, a bacterial infection, can lead to chronic inflammation that destroys gum tissue and the underlying alveolar bone. As the disease progresses, the bone supporting the teeth deteriorates, potentially causing teeth to loosen and eventually fall out.
Tooth extractions are a frequent cause of localized bone loss because the bone no longer receives stimulation from chewing, leading to its reabsorption. Trauma, such as a tooth being knocked out or a jaw fracture, can also disrupt bone stimulation and lead to deterioration. Misalignment of teeth, where certain teeth lack opposing structures, can result in uneven pressure on the jawbone, contributing to bone loss in less stimulated areas.
Infections can also affect the alveolar bone. Osteomyelitis, a bacterial infection of the bone and bone marrow, causes inflammation that can reduce blood supply to the bone and lead to its destruction. Abscesses, collections of pus often caused by severe tooth decay or gum disease, can extend into the bone, causing localized bone destruction. Tumors or cysts in the jaw can also destroy bone tissue.
Dental Treatments for Alveolar Bone Health
Dental treatments for alveolar bone issues often involve restoring lost bone or strengthening existing structures. Bone grafting is a common procedure used to replace missing or lost bone in the jaw, frequently performed before dental implant surgery or to address bone loss from infections or trauma. Grafting materials can be sourced from:
The patient’s own bone (autogenous)
Human donor bone (allograft)
Animal bone (xenograft)
Synthetic materials
These materials act as a scaffold, encouraging the body’s natural bone tissue to regenerate and fill the defect.
Dental implants rely on the health and quantity of the alveolar bone for successful integration. These prostheses are surgically placed into the jawbone, where they fuse with the bone through osseointegration. Bone grafting procedures like sinus lifts or ridge augmentations can prepare sites with insufficient bone for implants.
Orthodontic tooth movement also involves the alveolar bone, as teeth move through bone remodeling. The periodontal ligament fibers, stretched during orthodontic forces, stimulate osteoblasts to deposit new alveolar bone. In cases of reduced alveolar bone, such as from periodontitis or long-term tooth loss, bone grafting may be necessary before orthodontic treatment to ensure safe and effective tooth movement.
Managing bone infections, such as osteomyelitis, involves a combination of antibiotics and surgical removal of the affected bone. Following removal of infected bone, bone grafting may be required to restore function and promote new bone growth. These treatments aim to preserve or rebuild the alveolar bone, supporting long-term oral health and function.