What Is a Sagittal Split Osteotomy?

A sagittal split osteotomy is an oral surgery procedure that is done to correct any serious misalignment of the upper and lower teeth. The bone on the sagittal — or side — of the lower mandible of the jaw is cut on each side to form a split. This allows the front part of the mandible to slide backward or forward until the teeth are aligned. The bones are then held in place with screws and allowed to heal. Patients with a severe overbite or underbite may benefit from the sagittal split osteotomy.

Misalignment of the upper and lower teeth can occur when the mandible is either too long or too short. Patients with this condition may experience difficulty chewing, or they may have pain in the joint. They may also have a receding chin line. Surgery of the jaw, also known as orthognathic surgery, may provide some relief while improving the appearance of the face. Specifically, the sagittal split osteotomy is done to align the upper and lower teeth.

The dentist, orthodontist, and the maxillofacial surgeon need to evaluate the patient carefully and plan the surgical approach. Patients must have previously had their wisdom teeth or third molars removed. The dentist may also have the patient wear braces for up to six months prior to surgery in order to straighten the teeth. Planning the surgery also involves having x-rays of the entire mouth.

A sagittal split osteotomy is performed by a maxillofacial surgeon while the patient is under general anesthesia. Braces applied prior to surgery usually remain on the teeth during the procedure. All surgical incisions are made through the mouth so there is no visible scarring on the face after the procedure. The surgeon will begin by making an incision to expose the bone on each side of the mouth behind the last molars. A surgical saw will be used to slice the bone of the mandible lengthwise from the back of the jaw to the area beneath the second molars.

The front of the mandible is separated from the rear portion that extends to the ear. Large flat areas of the mandible bone are still in contact, which aids in the healing. Once the bone is cut on both sides, the front of the jaw can either be made to slide forward or backward to get the teeth aligned. Metal screws are then placed in the mandible to reattach the bone and allow healing to occur. New bone should form over top of the screws, so they should not need to be removed.

A full recovery following a sagittal split osteotomy may take several months. During the first week after the procedure, patients may need to take pain medication and antibiotics. Swelling in the jaw area may also be present for a few weeks. A diet in soft foods, good oral hygiene, and ice packs for the swelling can aid in recovery.