Maxillary prognathism is a condition characterized by the forward positioning or protrusion of the upper jaw (maxilla) relative to the lower jaw and the rest of the facial skeleton. This skeletal imbalance often results in a Class II malocclusion, where the upper front teeth extend significantly past the lower teeth. Successful treatment depends heavily on the patient’s age and the severity of the discrepancy. The approach differs dramatically for a growing child compared to a skeletally mature adult.
Identifying the Condition and Optimal Treatment Timing
The diagnostic process begins with a comprehensive evaluation by an orthodontist or oral surgeon, including clinical examination, dental molds, and various X-rays. A specialized X-ray called a lateral cephalogram provides a detailed side view of the skull and jaw relationship. Analysis of this image, known as cephalometric analysis, involves measuring specific angles to quantify the jaw positions, such as the SNA angle, which confirms the degree of prognathism.
Determining the patient’s skeletal maturity is a significant factor in treatment planning. Treatment during the growth phase (typically ages 7 to 14) allows for growth modification, which can redirect the development of the jawbones. Once growth is complete, treatment options are more restricted, often necessitating surgical intervention to correct the underlying skeletal structure. Accurate timing dictates whether non-surgical redirection of growth is possible.
Non-Surgical and Growth Modification Treatments
For patients whose facial bones are still developing, treatment focuses on modifying growth patterns to restrict the forward movement of the maxilla. Orthopedic appliances, such as headgear worn primarily at night, apply gentle pressure to the upper jaw, holding it back while the lower jaw continues its natural forward growth. This differential growth helps bring the jaws into better alignment. Functional appliances, which fit inside the mouth, are also used to encourage the mandible (lower jaw) to grow forward, indirectly reducing the upper jaw protrusion.
In skeletally mature patients with only mild prognathism, camouflage orthodontics may be an option. This non-surgical technique does not alter the jawbone position but uses braces or clear aligners to move the teeth within the jawbone, masking the skeletal discrepancy. For example, retracting the upper front teeth into spaces created by premolar extraction can reduce dental protrusion and improve the lip profile. Temporary Anchorage Devices (TADs), which are small mini-implants, provide a fixed anchor point, enhancing the ability of braces to retract the upper teeth with greater precision.
Surgical Correction for Severe Cases
When maxillary protrusion is severe and the patient is skeletally mature, orthognathic surgery is the definitive treatment to correct the underlying bone structure. The most common procedure for repositioning the upper jaw is the Le Fort I osteotomy. This process begins with pre-surgical orthodontics, where braces align the teeth so they will correctly interlock after the jaw repositioning. This preparation is required for a successful outcome and can take many months.
The surgery is performed under general anesthesia. Access to the maxilla is gained through an incision made entirely inside the mouth, ensuring no visible external scarring. Specialized instruments separate the tooth-bearing segment of the maxilla from the facial skeleton. This mobilized segment is then precisely moved backward to its planned position to correct the prognathism. The repositioned maxilla is secured using small titanium plates and screws, which permanently hold the bone in its new alignment.
Initial recovery involves significant facial swelling, peaking around two to three days post-surgery. Most swelling resolves within the first two weeks, though full resolution takes several months. Patients are hospitalized briefly and must adhere to a soft or liquid diet for several weeks to allow the bone to heal. Following surgery, a final stage of post-surgical orthodontics fine-tunes the bite, completing the correction.
Maintaining the Results
The final and longest phase of treatment is retention, necessary after both non-surgical and surgical correction. This stage is required because the surrounding soft tissues need time to reorganize around the newly positioned teeth and bone. Without retention, the teeth and jaw have a strong tendency to revert toward their original alignment, a phenomenon known as relapse.
Retention typically involves using both fixed and removable retainers. Fixed retainers are thin wires bonded permanently to the back surfaces of the front teeth, often used on the upper arch to prevent shifting. Removable retainers, such as clear plastic aligners or Hawley appliances, are worn full-time initially and then transition to nighttime use indefinitely. Long-term commitment to retainer wear is necessary, as the risk of relapse persists throughout life due to natural changes. Regular follow-up appointments monitor the stability of the results and ensure long-term success.