Extended vestibular incisions
A transoral approach is used for the majority of angle and ramus osteotomies.
The standard approach is a vestibular incision approximately 5 mm away from the attached gingiva, which is extended posteriorly along the anterior border of the ascending ramus.
For vertical ramus osteotomies some surgeons prefer transcutaneous approaches.
Sensory buccal nerve
The sensory buccal nerve crosses the upper anterior rim of the mandibular ascending ramus at the level of the coronoid notch. It is usually between the mucosa and the temporalis muscle fibers. When the posterior vestibular incision is carried sharply along the bony rim, the buccal nerve is at risk of transsection, followed by numbness in the buccal mucosal region. Therefore, to protect the nerve, the posterior dissection should be extended bluntly.
The photograph shows the sensory buccal nerve.
Unless contraindicated, infiltrate the area with a local anesthetic containing a vasoconstrictor.
Make an incision through the mucosa and periosteum in the vestibule approximately 5 mm away from the attached gingiva (in the mucogingival junction), extending up the external oblique ridge.
For adequate exposure of the ascending ramus the soft tissues have to be elevated from the bone in a subperiosteal plane. The lateral aspect of the mandible is exposed from the lower border to almost the sigmoid notch. On the medial aspect of the mandible only the area above the mandibular foramen is exposed to avoid damage to the inferior alveolar nerve.
For a standard bilateral sagittal split procedure (BSSO) the posterior border of the ascending ramus has to be freed from soft tissues. To create a working cavity and to protect the surrounding soft tissues special retractors are used.
The use of a transbuccal trocar may be necessary to assist in the placement of internal fixation hardware when using the extended vestibular approach.
Click here for a detailed description of the transbuccal technique.
After checking for hemostasis the wound is sutured in a single muco-periosteal layer.
A facial cooling mask is used to diminish postoperative swelling and associated pain.