The mode of origin, termination, course and number of branches of the marginal mandibular branch of the facial nerve were noted. Its relationship with the angle. This condition, known as " marginal mandibular nerve pseudoparalysis, " is caused by a lack of platysma depressive action on elevator muscles, giving an. Injury to the marginal mandibular nerve is present as an adverse outcome in mandibular nerve in relation to the inferior border of the mandible. . result in a pseudo-paralysis of the marginal mandibular nerve that usually.
It is due to paralysis of muscles of the lower lip of that side. The correction of resultant deformity may require complex surgical procedures like transfer of anterior belly of digastric muscle or extensor digitorum brevis.
Fifty facial halves were taken from adult embalmed cadavers irrespective of age and sex. A submandibular incision was given, extending posteroinferiorly from the tragus of the ear up to the symphysis menti, running below and parallel to the lower border of the mandible. After reflection of skin flap and fascia, the platysma muscle was separated from the underlying structures by blunt dissection.Marginal mandibular branch of the facial nerve - Know It ALL 🔊✅
Facial artery and the anterior facial vein were identified near the antero-inferior angle of the masseter muscle. The nerve was then traced from the vessel posteriorly up to the antero-inferior border of the parotid gland and anteriorly to its termination near the midline where it merges with fibres of muscles of the lower lip.
The mode of origin, termination, course and number of branches of the marginal mandibular branch of the facial nerve were noted.
Its relationship with the angle and inferior border of the mandible, with facial artery, with anterior facial vein and other surrounding structures was recorded.
Marginal mandibular branch of the facial nerve: An anatomical study
Its peripheral anastomoses with other branches of the facial nerve of the same and the opposite side were observed. This showed that branches were more at termination than the origin and course of the nerve.
Table 1 Number of branches of the marginal mandibular branch of the facial nerve at various levels No. There were no significant difference in position with respect to age and left versus right comparisons. Conclusion The marginal mandibular nerve MMN is significantly higher than previously published. The location of the nerve on the right does not correlate with the left. Marginal mandibular nerve MMNAngle of the mandible, Inferior border of the mandible, Subplatysmal flap, Neck dissection, Oral cancer Background The facial or VII cranial nerve is a mixed nerve composed of both motor and sensory branches and is responsible for the motor innervations of facial expression muscles, lachrymal secretion and partial control of the gustatory sensation [ 1 ].
The facial nerve enters the posteromedial surface of the parotid gland, crosses superficial to the external carotid artery and the retromandibular vein, divides into a number of branches that emerge separately from the gland and passes to supply the muscles of facial expression. Identification and preservation of the marginal mandibular nerve remains a critical step in otolaryngologic, cosmetic and oncologic head and neck surgery.
Iatrogenic injury to the marginal mandibular branch MMB during surgery of the neck often results in disorders of facial expression and has been an important reason of medicolegal actions [ 8 ].
Intraoperative localization of the marginal mandibular nerve: a landmark study
Injury to the marginal mandibular nerve is present as an adverse outcome in many surgical procedures. The resultant cosmetic deficit, manifesting lower lip asymmetry and imbalance, is readily noticeable especially during opening of the mouth [ 9 ]. The marginal mandibular branch supplies the muscles of facial expression that pull and close the angle of the mouth and pulls the lower lip downward depressor labii inferioris and depressor anguli oris.
The nerve passes along the inferior border of the mandible, often looping down into the neck, deep to the platysma and depressor anguli oris [ 10 ]. Due to its location, this branch can occasionally be damaged during cervical surgeries, parotidectomies, open reductions of mandibular angle fractures, rhytidoplasties and other surgeries confined to the submandibular region [ 12 ]. Also this higher incidence of injury to the marginal mandibular branch may be related to the proportionately greater number of operations in the region of the mandible, but must also be related to the lack of an accurate description of the course of this nerve in the anatomical textbooks [ 1314 ].
This is why the knowledge of the course and anatomic relations of the marginal mandibular nerve in the upper neck is important in avoiding injury [ 15 ]. Unrecognized or inadvertent injury results in a significant cosmetic deformity flattening and inversion of the ipsilateral lip that is very difficult to correct [ 8 ].
Distortion of the position of the facial nerve due to parotid tumors will also affect the position and anatomy of the marginal mandibular branch.
- Marginal mandibular branch of the facial nerve: An anatomical study
Perhaps one of the most challenging situations is associated with a displaced facial nerve in large or vascular tumors. It is important for the surgeon to maintain a hemostatic field to identify the nerve accurately.