The mandibular marginal ramus of the facial nerve: an anatomic and clinical study.

Injury to the mandibular marginal ramus of the facial n. constitutes a risk in cervicofacial surgery. The aims of this study were to define the origin of this nerve branch and its course and relations, especially with the lower border of the mandible and the facial vessels. Our observations revealed differences from the classical description of a single nerve branch traveling on the outer aspect of the body of the mandible above its lower border. We found several marginal branches, which become closely related to the facial pedicle, particularly the intermediate ramus, which can form a neural plexus around the facial a. They may follow a submandibular course, before but also after crossing the facial vessels. They are difficult to classify because of their great variability.