Alveolar bone loss is the gradual deterioration of the bone supporting the teeth. Also known as periodontal bone loss, this condition can lead to various complications if left unaddressed. Understanding its development and available interventions is important for maintaining oral health and preventing further issues.
What is Alveolar Bone Loss?
Alveolar bone is the specialized part of the jawbone that encases and supports tooth roots. It forms thickened ridges in the upper (maxillary) and lower (mandibular) jaws, creating sockets where teeth are held. This bone constantly undergoes natural resorption by osteoclasts and renewal by osteogenic cells.
The health of alveolar bone is directly linked to the presence and function of the teeth it supports. Chewing and biting stimulate the bone, which helps maintain its density and structure.
Alveolar bone loss occurs when bone resorption outpaces new bone formation, reducing its height and density. This can lead to the bone shrinking and exposing more tooth surface, making teeth appear longer.
Common Causes of Bone Loss
Periodontal disease is the primary reason for alveolar bone loss. It begins with plaque, a bacterial biofilm that accumulates on teeth, leading to gingivitis (gum inflammation). If untreated, gingivitis can progress to periodontitis, where bacterial infection and the body’s immune response destroy the periodontal ligament and underlying alveolar bone. This inflammation produces cytokines that promote bone resorption by osteoclasts.
Tooth extractions also contribute significantly to alveolar bone loss. When a tooth is removed, the bone that once supported it no longer receives chewing stimulation, causing it to atrophy and resorb. Research indicates that approximately 25% of the bone can be lost within the first year following an extraction, with this process continuing over time. Unanchored dentures and bridgework, which do not directly stimulate the underlying bone, can also lead to bone resorption.
Other factors also play a role in alveolar bone deterioration. Trauma to the teeth or jaw, such as a knocked-out tooth or jaw fractures, can result in bone loss. Misaligned teeth (malocclusion) can create uneven pressure on the jawbone, leading to reduced stimulation and subsequent bone deterioration. Systemic conditions like osteoporosis, which affects overall bone density, and poorly controlled diabetes, can also impact alveolar bone health. Additionally, infections, tumors, or cysts in the jaw can directly damage bone tissue.
Detecting Alveolar Bone Loss
Recognizing the signs of alveolar bone loss aids early intervention. Individuals might notice symptoms such as receding gums, where the gum tissue pulls back from the tooth surface, making teeth appear longer. Loose or shifting teeth are another indicator, as the supporting bone deteriorates. Changes in bite or difficulty chewing comfortably may also suggest underlying bone loss.
Dental professionals diagnose alveolar bone loss through a comprehensive clinical examination. This includes measuring gum pockets, also known as probing depths, using a small ruler to assess the space between the tooth and gum. Deeper pockets often indicate bone loss and inflammation.
Various imaging techniques are then employed to visualize the bone structure. Dental X-rays, such as periapical radiographs, panoramic X-rays, and cone-beam computed tomography (CBCT), provide detailed images of the jawbone and the extent of bone loss. These images allow dentists to evaluate the vertical distance between the cemento-enamel junction (CEJ) of the tooth and the alveolar crest, which helps quantify bone loss.
Treatment Options
Treatment aims to halt progression and, in some instances, regenerate lost bone. Non-surgical treatments are often the first line of defense, particularly for periodontal disease. Scaling and root planing is a deep cleaning procedure that removes plaque and tartar from below the gum line and smooths tooth roots to reduce bacterial buildup. Topical or oral antibiotics may be prescribed to help eliminate bacteria contributing to inflammation and bone loss.
Surgical interventions become necessary for more advanced cases. Flap surgery, also known as pocket reduction surgery, involves lifting the gum tissue for thorough cleaning and removal of diseased tissue, then repositioning gums to reduce pocket depth.
Bone grafting is a common surgical procedure where bone material is placed in areas of loss to encourage new bone formation. Different types of grafts can be used:
Autografts (bone from the patient’s own body, such as the jaw or hip)
Allografts (donor bone from a tissue bank)
Synthetic materials that mimic natural bone
These grafts integrate with existing bone over several months to restore strength and volume.
Guided tissue regeneration (GTR) is another surgical technique where a barrier membrane is placed between the gum tissue and the bone. This prevents faster-growing soft tissue from filling the bone defect, allowing slower-growing bone cells to regenerate. Sinus lift surgery, or sinus augmentation, is performed when there is insufficient bone in the upper jaw, particularly near the molars, by lifting the sinus membrane and placing grafting material. These treatments aim to stabilize teeth and prepare the jaw for potential dental implants.
Preventing Bone Loss
Proactive measures minimize or prevent alveolar bone loss. Maintaining excellent oral hygiene is foundational, including brushing teeth thoroughly twice a day and flossing daily to remove plaque and food particles. Regular dental check-ups and professional cleanings, typically every six months, allow dental professionals to remove hardened plaque (tartar) and detect early signs of gum disease before it progresses to bone loss.
Addressing underlying systemic health issues also plays a role in prevention. Managing conditions like diabetes effectively can reduce the risk of periodontal disease and associated bone loss. Avoiding risk factors such as smoking is also important, as it can increase the rate of alveolar bone loss and create an environment conducive to harmful bacteria.
Prompt treatment of any gum disease signs, such as red, swollen, or bleeding gums, can prevent the condition from advancing to periodontitis and causing bone damage. If a tooth is extracted, preserving the extraction site with a bone graft can help maintain bone density and integrity, preparing the area for future restoration like a dental implant. Dental implants, by replacing the tooth root, provide necessary stimulation to the jawbone, which helps prevent further bone resorption.