Double Jaw Surgery is a specialized medical procedure used to correct significant functional and aesthetic issues related to misaligned jaws. This intervention is typically reserved for cases where orthodontic treatment alone is insufficient to achieve proper alignment and bite. The surgery involves repositioning both the upper and lower facial bones to create a harmonious skeletal foundation. This process is a coordinated effort between an oral and maxillofacial surgeon and an orthodontist, often spanning an extended period of treatment.
Defining Double Jaw Surgery
The procedure commonly referred to as Double Jaw Surgery is technically known as bi-maxillary or two-jaw Orthognathic Surgery. This name reflects the two primary components of the operation: repositioning of the maxilla, or upper jaw, and the mandible, or lower jaw. The upper jaw is often moved using a Le Fort I osteotomy, while the lower jaw is typically repositioned through a bilateral sagittal split osteotomy (BSSO). The goal of this combined approach is to establish correct skeletal harmony and achieve proper dental occlusion.
Unlike single jaw surgery, the bi-maxillary approach allows the surgeon to correct complex three-dimensional discrepancies, including vertical, horizontal, and transverse alignment issues. By moving both jaws, the entire facial structure can be optimized for both function and appearance.
Conditions It Corrects
Double jaw surgery is indicated for individuals with dentofacial deformities that are too severe for braces or other non-surgical treatments to resolve. One of the most common reasons is severe malocclusion, specifically skeletal Class II (overbite) or Class III (underbite) relationships, where the bones themselves are mismatched in size or position. These skeletal issues can result in a significant overjet, underbite, or an open bite where the front teeth do not touch, impairing the ability to bite and chew food effectively.
Beyond bite mechanics, the surgery addresses significant facial disproportion or asymmetry. Functional impairments are also a major concern, including chronic difficulty with chewing, swallowing, or speaking clearly due to the misalignment. Furthermore, the procedure is highly effective in treating severe obstructive sleep apnea (OSA) caused by a retruded or small jaw structure. By moving the jaws forward, the surgeon expands the upper airway space, which can alleviate the obstruction that causes sleep-disordered breathing.
The Surgical Process and Preparation
The complete treatment timeline for double jaw surgery is a multi-stage process that often spans 18 to 24 months, with the surgery itself being only one phase. The initial stage involves pre-surgical orthodontics, where braces or aligners are used to position the teeth correctly over their respective jaw bones. This preparation, sometimes called “decompensation,” can temporarily make the malocclusion appear worse, but it is necessary to ensure the teeth fit perfectly after the jaws are moved.
Following the orthodontic preparation, the surgical planning phase utilizes advanced technology for precision. High-resolution computed tomography (CT) scans are used to create a three-dimensional composite skull model of the patient’s anatomy. Surgeons then use virtual surgical planning (VSP) software to simulate the exact movements of the maxilla and mandible, creating a highly accurate blueprint for the operation.
The surgery is performed under general anesthesia, typically lasting three to four hours in a hospital setting. The surgeon accesses the jawbones through incisions made entirely inside the mouth, meaning there are no visible external scars. Specialized tools are used to make precise bone cuts, known as osteotomies, which mobilize the upper and lower jaws. The jaws are then repositioned according to the pre-operative plan and held securely in their new position using small titanium plates and screws.
Post-Operative Healing and Management
The immediate post-operative period involves a brief hospital stay, usually one to four days. Patients should expect significant facial swelling, which typically peaks around the third day following the procedure. Pain is managed with prescribed medication, and the initial recovery often involves the use of elastic bands to guide the jaws into their final bite position.
A strict dietary regimen is implemented to allow the bone segments time to heal and consolidate. For the first four to six weeks, the diet must be entirely liquid or pureed, requiring no chewing. Patients must then progress to a non-chew or soft-food diet for several more weeks before gradually reintroducing firmer foods. Chewing too soon can disrupt the fixation and compromise the healing process.
Most patients can return to work or school within two to four weeks, though the face may still show residual swelling. Full bone consolidation takes several months. Following the bone healing, the final stage involves post-surgical orthodontics, typically lasting six to twelve months, to make minor adjustments and perfect the final dental alignment.