Marginal mandibular branch of the facial nerve
{{Short description|Nerve of the lower lip and chin}}
{{Infobox nerve
| Name = Marginal mandibular branch of the facial nerve
| Latin = ramus marginalis mandibularis nervi facialis
| Image = Gray788.png
| Caption = Plan of the facial and intermediate nerves and their communication with other nerves. (Labeled at center bottom, second from bottom, as "Mandibular".)
| Image2 = Ramusmarginalismandibularisnervifacialis.png
| Caption2 = The nerves of the scalp, face, and side of neck.
| Innervates =
| BranchFrom = Facial nerve
| BranchTo =
}}The marginal mandibular branch of the facial nerve arises from the facial nerve (CN VII) in the parotid gland at the parotid plexus. It passes anterior-ward deep to the platysma and depressor anguli oris muscles. It provides motor innervation to muscles of the lower lip and chin: the depressor labii inferioris muscle, depressor anguli oris muscle, and mentalis muscle.{{cite book |last=Drake |first=Richard |title=Gray's Anatomy of students |publisher=Churchill Livingstone elseveier |year=2010 |isbn=978-0-443-06952-9 |location=Philadelphia |pages=855–866}} It communicates with the mental branch of the inferior alveolar nerve.{{Citation needed|date=July 2023}}
Clinical significance
= Iatrogenic damage =
The marginal mandibular nerve may be injured during surgery in the neck region, especially during excision of the submandibular salivary gland or during neck dissections due to lack of accurate knowledge of variations in the course, branches and relations. An injury to this nerve during a surgical procedure can distort the expression of the smile as well as other facial expressions. The marginal mandibular branch of the facial nerve is found superficial to the facial artery and (anterior) facial vein. Thus the facial artery can be used as an important landmark in locating the marginal mandibular nerve during surgical procedures.Batra APS, Mahajan A, Gupta K. Marginal mandibular branch of the facial nerve: An anatomical study. Indian Journal of Plastic Surgery : Official Publication of the Association of Plastic Surgeons of India. 2010;43(1):60-64. doi:10.4103/0970-0358.63968. Damage can cause paralysis of the three muscles it supplies, which can cause an asymmetrical smile due to lack of contraction of the depressor labii inferioris muscle.{{Cite journal|last1=Hussain|first1=G|last2=Manktelow|first2=R.T|last3=Tomat|first3=L.R|date=September 2004|title=Depressor labii inferioris resection: an effective treatment for marginal mandibular nerve paralysis|url=https://doi.org/10.1016/j.bjps.2004.04.003|journal=British Journal of Plastic Surgery|volume=57|issue=6|pages=502–510|doi=10.1016/j.bjps.2004.04.003|pmid=15308395|issn=0007-1226|url-access=subscription}} This may be corrected with resection of the muscle, which tends to be successful.
Additional images
File:Lateral head anatomy detail.jpg|Lateral head anatomy detail
File:Slide1BAB.JPG|Lateral head anatomy detail. Neonatal dissection.
References
{{Gray's}}
{{Reflist}}
External links
- {{SUNYAnatomyLabs|23|06|01|03}} - "Branches of Facial Nerve (CN VII)"
- {{NormanAnatomy|lesson4}} ({{NormanAnatomyFig|parotid3}})
- {{NormanAnatomy|cranialnerves}} ({{NormanAnatomyFig|VII}})
- http://www.dartmouth.edu/~humananatomy/figures/chapter_47/47-5.HTM
{{Cranial nerves}}
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