Orthognathic surgery, commonly known as jaw surgery, is a complex corrective procedure designed to realign the upper jaw (maxilla) and/or the lower jaw (mandible) to correct irregularities causing functional problems. While orthodontics is effective for aligning teeth, surgery becomes necessary when the underlying skeletal structure is incorrectly positioned. This serious procedure is typically reserved for cases where less invasive treatments, such as braces or aligners, cannot resolve structural issues affecting speaking, chewing, and breathing.
Daily Functional Indicators
The primary signs suggesting a need for jaw surgery are those that interfere with daily functions. One common indicator is persistent difficulty with mastication, including biting, chewing, or swallowing food. When teeth do not meet correctly, uneven biting force can lead to premature tooth wear and digestive issues due to poorly broken-down food.
Chronic discomfort in the temporomandibular joint (TMJ) is another frequent sign. This pain, often felt near the ears, can include clicking, popping, or a locking sensation when the mouth is opened or closed. If non-surgical methods like splints, physical therapy, or medication fail to relieve this joint strain, the underlying skeletal misalignment may be the source.
Functional problems also manifest as challenges with speech articulation. A severe structural misalignment, such as an open bite, can interfere with the tongue’s ability to form specific sounds, potentially causing a lisp or slurred speech. The inability to naturally bring the lips together without visible straining (lip incompetence) suggests a skeletal disproportion too large for the surrounding soft tissues.
Diagnosing Severe Skeletal Misalignment
The need for surgery is confirmed by specific clinical findings pointing to a fundamental issue with the jaw bones themselves. These structural conditions involve discrepancies in the size or position of the maxilla and mandible, which cannot be corrected by simply moving the teeth with braces. Orthodontics is highly effective for dental misalignment, but only surgery can reposition the skeleton.
One key indicator is severe malocclusion, specifically Class II or Class III bite discrepancies, which are skeletal in origin. Class II malocclusion (retrognathism) involves a lower jaw positioned significantly behind the upper jaw, leading to a recessed chin appearance. Conversely, Class III malocclusion (prognathism) is characterized by a prominent lower jaw that sits too far forward, often resulting in an underbite.
Another structural problem requiring surgical intervention is a significant open bite, where a space remains between the upper and lower teeth even when the back teeth are closed. This prevents the ability to bite and tear food. Severe facial asymmetry, where one side of the face is noticeably different due to uneven jaw growth, also requires surgical correction to restore balance and function.
Critical Health Reasons Beyond Alignment
Jaw surgery is sometimes used primarily to manage serious health conditions, with bite correction being secondary. Maxillomandibular Advancement (MMA) is frequently recommended for treating severe Obstructive Sleep Apnea (OSA), which involves repeated episodes of airway collapse during sleep. For patients unresponsive to non-surgical treatments like Continuous Positive Airway Pressure (CPAP), MMA moves both the upper and lower jaws forward. This action pulls the soft tissues and tongue base forward, permanently increasing the size of the upper airway, stabilizing the breathing passage, and resolving the apnea.
Jaw surgery is also required for reconstruction following severe facial trauma that has displaced the jaw bones. Individuals with significant congenital defects, such as a severe cleft palate or other craniofacial anomalies, may require orthognathic surgery once skeletal growth is complete to restore proper function and structure. Surgery may also be considered for severe temporomandibular joint disorders that are unresponsive to conservative management, especially if the joint shows signs of advanced deterioration or chronic locking.
The Pre-Surgical Evaluation and Planning Process
The decision to proceed with jaw surgery results from a rigorous, multi-stage evaluation involving specialized healthcare professionals. The treatment is interdisciplinary, requiring close collaboration between an orthodontist and an oral and maxillofacial surgeon. The orthodontist aligns the teeth within each jaw, while the surgeon focuses on repositioning the jaw bones.
The planning phase relies heavily on advanced diagnostic imaging. This includes specialized X-rays, such as cephalometric radiographs, and three-dimensional Cone-Beam CT scans to accurately visualize the skeletal structure. Analysis of these images allows the surgical team to perform virtual surgical planning, calculating the exact movements of the maxilla and mandible to a fraction of a millimeter.
Preparation involves pre-surgical orthodontics, a phase typically lasting between 12 and 18 months. During this time, the orthodontist uses braces to move the teeth into the precise positions they will need to be in after the skeletal correction. This temporary dental alignment often makes the bite appear worse before surgery, but it is necessary to ensure the teeth fit together correctly once the jaws are surgically realigned.