Marginal mandibular branch of the facial nerve: An anatomical study

Abstract

Smile is one of the most natural and important expressions of human emotion. Man uses his lips mainly to register his emotions. Thus, the slightest asymmetry or weakness around the lips and mouth may transform this pleasant expression into embarrassment and distortion. The circumoral musculature, the major part of which is supplied by the marginal mandibular branch of the facial nerve, is the main factor in this expression. Therefore, an injury to this nerve during a surgical procedure can distort the expression of the smile as well as other facial expressions. This nerve often gets injured by surgeons in operative procedures in the submandibular region, like excision of the submandibular gland due to lack of accurate knowledge of variations in the course, branches and relations. In the present study, 50 facial halves were dissected to study the origin, entire course, termination, branches, muscles supplied by it, its anastomoses with other branches of facial nerve on the same as well as on the opposite side and its relations with the surrounding structures. The marginal mandibular branch of the facial nerve was found superficial to the facial artery and (anterior) facial vein in all the cases (100%). Thus the facial artery can be used as an important landmark in locating the marginal mandibular nerve during surgical procedures. Such a study can help in planning precise and accurate incisions and in preventing the unrecognized severance of this nerve during surgical procedures.

Terminal Branching Pattern of Facial Nerve Seen in Adult Cadavers: An Anatomical Study

“…The intricate anatomic division pattern of the facial nerve, the dramatic deformities consequentially from its injury and its decisive role in facial expressions have enthused numerous anatomic and exploratory studies on the nerve. [1][2][3] The choice of the surgical approach is very linked to the parotid surgery because the practical significance of the branches of facial nerve and the intense anatomic randomness of the parotideal area. 4 The facial nerve emerges from the base of the skull at the stylomastiod foramen.…”

Triangle of Marginal Mandibular Branch (MMB): Anatomical Zone, Constant Reference of the MMB in Cervical Surgical Position

“…This result is similar to that of Yang et al (2016) (21) carried out on 29 hemifaces who reported that in 82.8% of cases the MMB was less than 5 mm below the angle of the mandible and in 89.7% of the MMB was less than 10 mm below the angle of the mandible. However, the results of Batra et al (2010) (15) are different MMB 52% along the mandibular angle and 16% in the latter.…”

“…This involves searching for the MMB before its intersection with the facial vein, whether before point X, which further reduces the locating area. The study by Batra et al (2010) (15) made on 50 hemifaces human cadavers joins our study and describes the marginal branch of the mandible as a single branch to its origin in 88% of cases, 92% during the course, but It rarely single branch at termination (4% of cases).The MMB was divided into two branches in 12% of the cases at its origin, 8% of cases during the course and 12% of the cases at its termination. In almost all anatomical subjects (84% of cases) the MMB had more than two branches at its termination.…”

“…Woltmann et al (2006) (8) reported that in 40 hemifaces, MMB anastomosed to 22% with cervical branch and 42% oral branch, but 36% showed no MMB anastomoses. (15) reported that in 50 hemifaces of cadavers, the MMB communicated with the cervical branch in 28% of cases and with the buccal branch in 12% of cases. Balagopal et al (2012) (16) noted that in 202 hemifaces, MMB anastomosed to 24% with the cervical branch.…”

“…For this reason, they think that the incision should not be as far as 3-4 cm below LBM. The study by Batra et al (2010) (15) performed on 50 cadavers fixed in formalin, determined that the situation of the MMB farthest LBM was 1.5 cm with a maximum distance of 1.6 cm. Thus, they determine an incision ≥ 1.6 cm.…”