Orthognathic surgery, or jaw surgery, realigns the jaws and teeth to improve their function and the facial proportion. Surgery performed on the upper jaw is often referred to as LeFort 1, and surgery on the lower jaw is bilateral sagittal split osteotomy (BSSO). Orthognathic surgery is often performed in patients with malocclusion (poor teeth alignment when the jaws are closed) including patients with cleft lip/palate, Piere Robin Sequence, hemifacial microsomia, Treacher Collins, or other major craniofacial abnormalities. Commonly treated malocclusions are underbite (lower teeth is in front of upper teeth), overbite (upper teeth is in front of lower teeth), crossbite (upper teeth cross behind lower teeth), and anterior open bite (front upper and lower teeth cannot touch when the jaws are closed). Surgical correction is indicated with orthodontia alone cannot correct teeth malocclusion.
Jaw surgery can also be performed to increase the size of the airway to treat patients with obstructive sleep apnea.
LeFort 1 and BSSO are the most common orthognathic surgery. Some patients require upper jaw expansion in addition to jaw movement. Expansion can often be accomplished with palatal expansion. However, on some occasion, Surgically assisted maxillary expansion (SAME) may be necessary.
For optimal correction, pre-op and post-op orthodontia treatment is strongly recommended. When both jaws require surgery, virtual surgical planning (VSP) based on patient’s teeth model and Computed Tomography (CT) images is performed to account for and address all abnormalities.
Who is a good candidate for orthognathic surgery?
Corrective jaw surgery is performed after growth stops, usually around ages 14 to 16 years for females and ages 17 to 21 years for males. Patients with medical problems are candidates for surgery as long as they are in their optimal health and are well informed of their peri-operative risks. For patients who seek correction of misaligned jaws, orthodontia treatment is often necessary before and after surgery.
How is the surgery performed?
Jaw surgery are performed through incisions hidden inside the mouth and can be done to just single jaw or both jaws. Most surgeries are planned virtually along with the orthodontists to optimize outcome and reduce orthodontia treatment time. If teeth alignment is not the main concern, the advancement of both jaws are also virtually planned to maximize the airway without compromising post-op speech. During surgery, cuts are made in the bone to allow for free movement of the teeth bearing segments. The segments are then fixed in place with plate and screw based on the pre-op planning. Orthognathic surgery can be combined with genioplasty to correct any residual asymmetry of the lower jaw bone.
What is the recovery?
Most patients requires one overnight stay in the hospital or surgery center for monitoring and pain control. Significant swelling of the face is expected in the first week and often resolved by one month. After surgery, elastic bands may be present to guide the alignment of the jaws. Patients are recommended to have soft diet for 3-4 weeks and are expected to lose 10-15 pounds post-operatively due to diet restriction and discomfort. Close follow up and continued treatment with orthodontists are vital to surgical success for jaw realignment.