An asymmetrical jaw, or mandibular asymmetry, is a condition where the lower jaw or other craniofacial structures lack balance between the left and right sides. This difference can stem from issues with the teeth, surrounding musculature, or the underlying skeletal structure of the face. Because causes vary widely, from minor dental misalignment to significant bone discrepancy, the appropriate correction depends entirely on accurately identifying the specific origin of the imbalance.
Diagnosing the Source of Asymmetry
Determining the source of asymmetry is the foundational step before treatment begins. Specialists, such as orthodontists and oral and maxillofacial surgeons, collaborate to perform a comprehensive clinical examination. This process involves assessing facial proportions, evaluating dental occlusion, and checking for signs of temporomandibular joint disorder (TMD), which often involves muscular imbalances.
Imaging techniques provide objective data to quantify skeletal and dental deviations. Standard two-dimensional X-rays, such as panoramic and cephalometric images, offer initial views of the bone structure and teeth. For detailed, three-dimensional analysis, Cone-Beam Computed Tomography (CBCT) scanning is the preferred method. CBCT allows for precise measurement of size, shape, and spatial orientation differences. This imaging confirms whether the issue is primarily dental (malocclusion), muscular, or skeletal (dentofacial deformity).
Non-Surgical and Conservative Treatments
When the asymmetry is mild or moderate, non-surgical approaches are often considered first to correct or mask the imbalance. This category includes orthodontic camouflage, which focuses on manipulating the position of the teeth to compensate for a minor underlying jaw discrepancy. Using braces or clear aligners, the orthodontist moves teeth asymmetrically to align the dental midlines and improve the overall bite. This technique is a viable alternative for patients who have completed growth or whose skeletal imbalance does not warrant major intervention. Successful camouflage often requires careful asymmetric tooth movement, sometimes involving tooth extractions or temporary anchorage devices like mini-screws, to create a functional and visually balanced bite.
Asymmetry can also be significantly influenced by muscular factors, particularly those related to the temporomandibular joints. In these cases, orofacial myofunctional therapy (OMT) addresses muscle imbalances and improper tongue posture that contribute to the jaw’s resting position and function. Through a series of targeted exercises, OMT helps retrain the muscles of the face, mouth, and tongue to promote proper function and relieve strain on the jaw joints. OMT is an effective treatment for TMD symptoms, such as chronic jaw pain or clenching. By strengthening weakened muscles and improving coordination, OMT aims to normalize jaw movement and position, leading to a gradual improvement in functional asymmetry.
Orthognathic Surgery and Structural Correction
For patients with significant skeletal asymmetry, often termed dentofacial deformity, the definitive treatment is orthognathic surgery, commonly known as corrective jaw surgery. This complex procedure is necessary when the size or position of the upper jaw (maxilla) or lower jaw (mandible) is too divergent for orthodontics alone to correct. The surgery physically repositions the jawbones to achieve proper alignment and facial balance.
The process is a collaboration between the oral and maxillofacial surgeon and the orthodontist, beginning with pre-surgical orthodontics that typically lasts 12 to 18 months. During this time, teeth are moved into alignment over their respective jawbones, which often makes the bite temporarily appear worse before surgery. Advanced three-dimensional planning, called Virtual Surgical Planning (VSP), uses CBCT scans to precisely map out the required bone movements.
During the surgery, performed under general anesthesia, the surgeon makes controlled cuts, called osteotomies, in the jawbones. Depending on the specific asymmetry, this may involve a single-jaw surgery, such as a bilateral sagittal split osteotomy (BSSO) on the mandible, or a double-jaw surgery, combining a BSSO with a Le Fort I osteotomy on the maxilla. The jaw segments are then repositioned into the planned, corrected location and secured with small titanium plates and screws, which typically remain permanently in the bone.
Following the procedure, the patient begins recovery involving a liquid or non-chew diet for approximately four weeks to allow for initial bone healing. The initial recovery period lasts about six weeks, though full bone remodeling and final healing can take several months. This surgery is the most powerful method for correcting severe skeletal imbalances, providing both functional bite correction and significant improvement in facial symmetry.
Life After Treatment and Maintaining Results
Maintaining the stability of the new jaw and bite position is paramount. For surgical patients, a post-operative phase of orthodontics begins approximately six to eight weeks after the operation to fine-tune the final bite relationship. This phase typically lasts an additional three to six months to ensure the teeth interlock perfectly in the newly established jaw position.
Once active treatment is complete, long-term stability relies heavily on the consistent use of retainers for both the upper and lower arches. Retainers are passive appliances that prevent the teeth from gradually shifting back toward their original positions, a phenomenon known as orthodontic relapse. Fixed retainers, which are thin wires bonded to the back of the front teeth, are often used in combination with removable retainers worn at night.
Regular follow-up appointments with specialists are necessary to monitor the occlusion and ensure the results remain stable. For patients treated for TMD, continued adherence to prescribed muscle exercises or lifestyle modifications, such as managing clenching habits, is important. While major repositioning movements tend to be more stable, subtle changes can occur, making long-term retention protocols essential for preserving corrected symmetry.