The marginal mandibular nerve of the face, vascular and nerve relations: anatomy and clinical relevance

Background: The marginal mandibular nerve (MMN) is the branch of the facial nerve that is injured most frequently 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 the anatomy of the MMN. The studies to date are not in agreement regarding the number of branches of the MMN and its relationship with the vasculature and other nerves. Methods: This study involved dissection of 62 half-heads from cadavers. Results: In 22.58% 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%), the MMN had two branches. In 12.9% of the cases, the MMN gave rise to three branches. In 17 cases (35.48%), the MMN gave rise to between four and more than ten branches, thereby forming a plexus at its end. Analysis of this collection of cases revealed that the MMN was more consistently lateral to the facial vein than to the facial artery. The MMN exhibited connections with other branches of the facial nerve and branches of the trigeminal nerve. Conclusion: The facial vein had a more consistent relationship with the MMN than the facial artery. This study provides the anatomical bases of substitution, proprioception, and clinical variations in injuries of the MMN and in their prognosis. Financial disclosure: The authors have no conflicts of interest or specific sources of funding to declare. Acknowledgements: The author thanks those who donated their bodies for anatomical research and the Laboratoire d'anatomie, Paris. Acknowledgments: The authors thank those who donated their bodies for anatomical research and the Laboratoire d'anatomie, Paris. Author Participation : GT conceived of and chose the topic to be investigated and the methodology, performed the dissections, and wrote the manuscript. He discussed these various aspects with the coauthors. MKTF, TR, SV, and VP participated in dissection sessions and in the bibliographic research. CV participated in writing-up the study and preparation of the manuscript. Corresponding author: Gaoussou Touré, Service de chirurgie maxillofaciale–chirurgie plastique, Centre hospitalier intercommunal, 40 allée de la source, Villeneuve Saint-Georges 94195, France. Email:gaoussou.toure@chiv.fr; gtoure1@gmail.com ©2018American Society of Plastic Surgeons

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