RESUMO
BACKGROUND: The marginal mandibular nerve of the facial nerve is frequently injured during corrective and cosmetic surgery. Recent or emerging techniques such as the injection of filler materials, botulinum toxin, allotransplantation of composite tissues of the face, placement of chin implants, and submental cryolipolysis require in-depth knowledge of this nerve. The studies to date are not in agreement regarding the number of branches of the marginal mandibular nerve and its relationship with the vasculature and other nerves. METHODS: This study involved 62 half-heads from cadavers. RESULTS: In 22.6 percent of the cases, the marginal mandibular nerve of the facial nerve was a single branched entity and lateral to the pedicle, with respect to the facial artery and the facial vein. In 16 cases (29 percent), the marginal mandibular nerve had two branches. In 12.9 percent of the cases, the marginal mandibular nerve gave rise to three branches. In 17 cases (35.48 percent), the marginal mandibular nerve gave rise to between four and more than 10 branches, thereby forming a plexus at its end. Analysis of this collection of cases revealed that the marginal mandibular nerve was more consistently lateral to the facial vein than to the facial artery. The marginal mandibular nerve exhibited connections with other branches of the facial nerve and branches of the trigeminal nerve. CONCLUSIONS: The facial vein had a more consistent relationship with the marginal mandibular nerve than the facial artery. This study provides the anatomical bases of substitution, proprioception, and clinical variations in injuries of the marginal mandibular nerve and in their prognosis.
