Bone loss around the teeth, specifically alveolar bone loss, is a common concern for people considering orthodontic treatment. The alveolar bone is the specialized structure that supports the roots of the teeth and must be healthy for successful tooth movement. Orthodontic alignment works through bone remodeling, where forces applied by braces or aligners stimulate cells to break down bone on one side and rebuild it on the other, allowing the tooth to shift. When a tooth lacks adequate bone support, this remodeling process is compromised, increasing the risk of complications. Despite these challenges, reduced bone support does not automatically prevent treatment; orthodontic correction is often achievable with specific modifications and careful planning.
Prerequisites: Stabilizing Underlying Bone Loss
Before any tooth movement begins, the primary cause of bone loss, typically uncontrolled periodontal disease, must be fully arrested and stable. Stabilization is the first step because active inflammation accelerates bone destruction during orthodontic treatment. This phase requires a comprehensive assessment, often including detailed full-mouth X-rays or a Cone-Beam Computed Tomography (CBCT) scan, to accurately measure the remaining bone level around each tooth.
The patient must receive clearance from a periodontist, confirming that the disease is under control and the gum tissues are healthy. This involves thorough deep cleaning procedures like scaling and root planing to remove plaque and tartar deposits below the gum line. Maintaining meticulous oral hygiene is mandatory throughout the entire orthodontic process, as appliances can make cleaning more difficult and encourage inflammation. Only when the periodontium is deemed healthy and stable can active tooth movement proceed.
Specialized Orthodontic Techniques for Reduced Bone
Moving teeth with reduced bone support requires a different biomechanical approach to minimize stress on the compromised roots. The primary modification involves using significantly lighter, sustained forces, proportional to the reduced root surface area still embedded in bone. For example, the ideal force for an intrusive movement in a tooth with bone loss is typically between 5 and 10 grams per tooth, which is much lower than the forces used in a healthy mouth.
This light force delivery is often achieved through specialized appliance designs, such as segmental arch techniques, which allow the orthodontist to apply highly localized forces. Clear aligner systems can also be a suitable option because they deliver gentler, incremental forces that promote gradual movement. For cases requiring more complex movements, Temporary Anchorage Devices (TADs)—small, temporary implants placed in the bone—can be employed strategically. TADs provide stable anchor points, which helps prevent unwanted movement in teeth that already have reduced support.
Managing Treatment Risks and Ensuring Long-Term Retention
Orthodontic treatment on a reduced periodontium carries specific, elevated risks that must be understood before starting. One primary concern is the potential for external apical root resorption, which is the shortening of the tooth root. While minor root shortening is common in all orthodontic cases, the risk is higher in a compromised environment, and excessive movement, particularly intrusion, can exacerbate this issue.
Another consideration is the heightened risk of relapse, where corrected teeth shift back toward their original position after the braces are removed. Teeth with less surrounding bone are naturally less stable, making the long-term retention phase mandatory for maintaining alignment. This typically involves the use of permanent, bonded retainers—thin wires attached to the back surfaces of the teeth—often supplemented by removable retainers worn at night. Ongoing, regular periodontal maintenance appointments are crucial after treatment to monitor the stability of bone and gum health over time.