Bone loss in the teeth, properly termed alveolar bone loss, refers to the erosion of the jawbone that supports the roots of the teeth. This loss of physical support is progressive and does not reverse naturally. When the bone structure deteriorates, it compromises the stability of the teeth, leading to mobility and ultimately, tooth loss. Addressing this condition requires professional intervention to halt the destruction and, in some cases, attempt to regenerate the lost tissue.
Understanding Alveolar Bone Loss
The alveolar bone is the specialized bony ridge in the upper and lower jaws that contains the sockets, or alveoli, which physically anchor the roots of the teeth. Its primary function is to provide the necessary support for the forces generated during chewing and biting. This bone is unique because its existence is dependent on the presence of the teeth it surrounds.
When bone loss occurs, it is categorized by the pattern of destruction observed on dental X-rays. Horizontal bone loss describes a uniform reduction in the height of the bone along the entire arch. Conversely, vertical bone loss, also known as angular defects, involves localized, wedge-shaped areas of destruction adjacent to a specific tooth root. Unlike systemic bone conditions, alveolar bone loss is typically a localized inflammatory process triggered by a local bacterial infection.
How Periodontal Disease Causes Bone Deterioration
The primary cause of alveolar bone loss is chronic periodontal disease, which begins with the accumulation of a bacterial film called plaque. If plaque is not removed, it hardens into tartar, providing a rough surface where more bacteria thrive, leading to gingivitis, a reversible inflammation of the gums. If this inflammation persists without treatment, it progresses into periodontitis, which is characterized by irreversible destruction of the supporting structures.
In periodontitis, bacteria release toxins that provoke a strong immune response. This attempt to eliminate the infection leads to chronic inflammation, causing the destruction of the periodontal ligament and bone. Immune cells produce pro-inflammatory signaling molecules, which manipulate the body’s bone remodeling system.
This destructive process involves the body’s bone remodeling system. While bone resorption and formation are normally balanced, chronic inflammation stimulates the activation of osteoclasts. Osteoclasts are the cells responsible for breaking down and resorbing bone tissue. This sustained, uncontrolled activity leads to a net loss of alveolar bone mass.
Recognizing the Signs of Advanced Bone Loss
The symptoms of advancing periodontal disease can be subtle initially, but they become more noticeable as supporting bone is lost. A common early sign is persistent bad breath (halitosis) and gums that bleed easily when brushing or flossing. Patients may notice that their teeth appear longer than they used to, which is caused by gum recession as the soft tissue pulls away from the root surface.
As the underlying bone continues to disappear, spaces can begin to appear between the teeth, often referred to as “black triangles.” The loss of supporting bone structure eventually causes the teeth to become unstable. This instability manifests as tooth mobility, or loose teeth, which is a late-stage symptom indicating a severe reduction in structural support.
To confirm the presence and extent of bone loss, dental professionals rely on two main diagnostic tools. A small instrument is used to measure the depth of the periodontal pockets between the tooth and the gum line; depths greater than 5 millimeters suggest significant disease activity and tissue detachment. This clinical measurement is supplemented by dental X-rays, or radiographs, which provide a visual representation of the bone level and pattern of loss, distinguishing between horizontal and vertical defects.
Treatment Strategies for Stabilization and Repair
The initial intervention for bone loss is always focused on stabilization, which involves eliminating the bacterial cause of the inflammation. The non-surgical procedure known as Scaling and Root Planing (SRP) is performed to achieve a deep cleaning below the gum line. Scaling removes the plaque and hardened tartar from the tooth surface and the root, while root planing smooths the root surface to remove bacterial toxins and discourage future bacterial accumulation.
If the disease is too advanced or pockets remain deep after SRP, surgical options are considered to access the deeper disease sites and attempt regeneration. Flap surgery involves lifting the gum tissue to allow the periodontist to fully clean the root surfaces and reshape the bone before suturing the gums back into place. For defects where regeneration is possible, Guided Tissue Regeneration (GTR) or Guided Bone Regeneration (GBR) techniques are used.
These regenerative procedures often involve the placement of a bone graft material into the defect to stimulate new bone growth. Graft materials can include bone harvested from the patient (autogenous), human donors (allografts), animal sources (xenografts), or synthetic materials. A physical barrier membrane is frequently placed over the graft to block fast-growing soft tissue cells from migrating into the space, reserving the area for slow-growing bone cells. Achieving long-term success requires strict post-treatment maintenance, involving frequent professional visits to monitor pocket depths and ensure the disease does not recur.