Orthognathic surgery, commonly known as jaw surgery, is a treatment designed to correct severe skeletal discrepancies between the upper and lower jaws that cannot be resolved with orthodontics alone. This procedure involves repositioning the jaw bones to improve facial balance, chewing function, and oral health. Since the underlying structure of the face is physically altered, the standard approach involves using braces to prepare the teeth for the surgical change. While braces are a near-universal part of the process, the precise timing—before or after the procedure—varies depending on the patient’s specific needs and the chosen treatment method.
The Purpose of Pre-Surgical Orthodontics
The primary goal of wearing braces before jaw surgery is dental decompensation. Skeletal issues, such as an underbite or overbite, often cause the teeth to naturally tilt and move into positions that camouflage the underlying jaw problem, known as dentoalveolar compensation. For example, in a person with a small lower jaw, the lower front teeth may lean forward in an attempt to make contact with the upper teeth.
Pre-surgical orthodontics works to “undo” this natural compensation by moving the teeth into their ideal, stable positions relative to their jaw bone. This movement is necessary because the surgeon relies on the teeth being correctly aligned over the bone to accurately plan and execute the jaw repositioning. The teeth must be straight on their respective jaw to ensure they meet correctly after the bone is repositioned.
This phase often temporarily makes the patient’s bite look significantly worse, as the teeth are moved out of their camouflaged alignment and into their true skeletal positions. This worsening of the malocclusion is a necessary step that reveals the full extent of the skeletal discrepancy the surgery must correct.
The preparatory phase typically requires between 12 to 18 months of active orthodontic treatment. This time is used to achieve leveling and alignment of the dental arches, eliminate occlusal interferences, and coordinate the width of the upper and lower arches.
The fixed orthodontic appliances applied during this time are used for tooth movement and serve a structural purpose during the operation. The braces provide a rigid foundation for the surgeon to stabilize the jaws immediately after the bone is repositioned. This collaboration between the orthodontist and the oral surgeon is crucial, ensuring the teeth are positioned to allow the planned skeletal movements to achieve the best functional and aesthetic result.
When Braces Are Not Needed First
While the conventional approach involves pre-surgical orthodontics, the “Surgery-First Approach” (SFA) offers an alternative sequencing. This technique bypasses the lengthy preparatory phase, proceeding directly to the jaw surgery. The skeletal correction is performed immediately, and the orthodontic alignment begins days or weeks after the operation.
The main advantage of SFA is a faster initial improvement in facial appearance, addressing the patient’s primary concern sooner in the treatment timeline. Performing the surgery first also takes advantage of the Regional Acceleratory Phenomenon (RAP), a period of heightened biological activity in the bone following surgery. This phenomenon is thought to speed up post-operative tooth movement, which can significantly shorten the time a patient spends in braces.
However, the surgery-first approach is not suitable for everyone and requires careful patient selection. Ideal candidates have minimal dental crowding and only minor dental discrepancies in the vertical or transverse planes. Cases requiring tooth extractions or those with severe dental compensation are more difficult to manage with SFA.
The primary challenge of SFA is that the patient experiences a more pronounced bite discrepancy immediately following the surgery. Because the teeth were not pre-aligned, they do not interdigitate well after the jaws are moved, requiring the orthodontist to work with a non-ideal “transitional occlusion.” This sequencing demands highly precise planning, as the surgeon cannot rely on the pre-aligned teeth to guide the final jaw position.
Refining the Bite After Surgery
Following the surgical procedure, the patient enters the final phase of treatment, focusing on refining the dental occlusion. Once the jaw bones are stable, the orthodontist begins the post-surgical tooth movement, which typically lasts between six to twelve months. This stage is dedicated to achieving the final fit between the upper and lower teeth.
A major component of this phase is the use of intermaxillary elastics, commonly known as rubber bands, worn between the upper and lower braces. These elastics apply light, continuous force to settle the bite, ensuring each cusp of the tooth fits precisely into the opposing groove. They are also used to correct minor shifts or rotations that may have occurred during the recovery period.
The goal is to achieve maximal intercuspation, where the teeth lock together securely, providing long-term stability and functional efficiency. Once the ideal bite is achieved, the braces are removed, and the final step begins: retention. Retention is necessary to prevent the teeth from gradually shifting back toward their original positions.
Retention involves the use of retainers, which may be fixed wires bonded behind the front teeth or removable clear appliances worn primarily at night. Since the bone surrounding the teeth undergoes remodeling for up to a year after surgery, retention is important to stabilize the result achieved by the surgery and the orthodontics. The long-term success of orthognathic treatment depends heavily on consistent retainer wear to maintain the new skeletal and dental alignment.