Anatomical Variations of Mylohyoid Nerve and Its Clinical Significance: A Cadaveric Study with Review of Literature.

Abstract

Purpose: Inferior alveolar nerve is commonly encountered by the dental and maxillofacial surgeons in their routine dental practice. This nerve usually gives off a mylohyoid branch before it enters the mandibular foramen. Though predominantly considered to be motor nerve, mylohyoid nerve has also sensory innervations to inferior part of chin and aids in speaking, chewing and swallowing. This paper attempts to throw an insight into the various anatomical patterns of inferior alveolar nerve in infratemporal fossa as observed in cadaveric dissection of 40 specimens.

Methods: The study involved bilateral dissection of 20 human heads comprising a total of 40 dissected sides of infratemporal fossa to observe the nerve pattern.

Results: The inferior alveolar nerve followed its regular anatomical pattern in 37 specimens. Anomalies in its branching pattern were noted with respect to mylohyoid nerve in 3 of 40 specimens-7.5%. Two specimens had mylohyoid nerve branching directly from mandibular nerve, and one specimen had medial branching pattern of mylohyoid nerve.

Conclusion: Anatomical variations are rare but can occur. Variations in relation to branching patterns of mylohyoid nerve have been described in this article with review of literature. Knowledge and understanding about these anatomical variations are essential for the dental surgeons to identify the cause of failure after local anesthetic injections, to recognize the signs and symptoms of nerve damage and for the preservation of nerve during major surgical procedures.