Access to the jaw angles, whether for aesthetic implant placement or to perform sagittal split osteotomies, uses an incision overlying the external oblique line on the bone. While often viewed as having no significant structures between the mucosa and this bony ridge line this is not entirely accurate. The buccal neurovascular bundle runs in proximity to this incision and it would not be rare to encounter it during surgery. While injury to the buccal artery or vein only poses an intraoperative nuisance , injury to the nerve has no immediate intraoperative effects but may have some postoperative ones.
The buccal nerve is a branch of the anterior division of the trigeminal nerve and is only responsible for sensation. This sensation affects the intraoral buccal mucosa, gums of the lower premolar and molar teeth and some areas of the external cheek skin. The nerve emanates from the mandibular nerve before it heads into the bone, courses between the two heads of the lateral pterygoid muscles, goes under the temporalis muscle tendon below the coronoid process, comes across the anterior border of the ramus of the mandible and then under the buccal mucosa to finally pierce into the buccinator muscle. It is near this terminal end of the nerve where an incision over the external oblique ridge and the nerve’s course may collide.
The key to avoiding injury to the long buccal nerve is not to go too lateral with the incision. While it it important to leave a good medial musculomucosal cuff of tissue for secure incisional closure, getting too far lateral will risk inadvertent transection of the neurovascular bundle since electrocautery is commonly used for the dissection. Or during incisional closure the nerve may become entrapped in the initial muscle closure over the implant.
While cheek numbness would be the usual sequelae of buccal nerve injury it always possible to develop a more painful neuroma. Knowledge of the course of the nerve and awareness of its potential location is the key to avoiding injury to it.
Dr. Barry Eppley
World-Renowned Plastic Surgeon