Detection methods for marginal mandibular branch of facial nerve: a literature review

Abstract

Purpose After orofacial surgery, some patients’ quality of life are lowered due to iatrogenic injury of the marginal mandibular branch (MMB). Therefore, methods that can localize and protect the MMB before or during orofacial surgery were reviewed through a literature review.

Material and Methods Total of ten documents were sourced through a PubMed search. Depending on the methods that can navigate the MMB, the studies were categorized into landmarks’ utilization, ultrasound scanning techniques, nerve stimulators, and fluorescent dye techniques.

Results In the cases of using landmarks, there were methods that used a layer with facial artery and facial vein. Also, the location of MMB inferred by making the triangle based on mouth commissure, sternocleidomastoid muscle, mandibular groove, mastoid, and mastoid apophysis. There was also a technique for visualizing an MMB via ultrasound scanning. The portable and disposable nerve simulator enabled an accurate MMB identification. Moreover, MMB mapping using a stimulator could help in the security and protection of the nerve during surgery. Finally, using a fluorescent dye (which is currently limited to animal study) could make visualization of MMB and micro branches.

Conclusion Most orofacial surgeries still rely on landmarks to search for the MMB. However, it is believed that damage to the MMB can be reduced by using the various techniques identified in this review paper in clinical practice.