A recurrent variant branch of the inferior alveolar nerve: Is it unique?

Abstract

The only named branch of the inferior alveolar nerve (IAN) before it enters the mandibular foramen is the mylohyoid nerve. However, several variations have been reported in the literature. In this study, a recurrent variant branch of the IAN arising just below the origin of the mylohyoid nerve was investigated in adult Indian cadavers allotted for dissection to the first year dental students of Government Dental College, Ahmedabad (India). The dissection was performed by the lateral approach to the infratemporal fossa. The nerve was found in 12 of 35 sides (34.3%) and 8 of 18 cadavers (44.4%). Thus, in our study it was not a rare variation of the IAN, where in most cases it innervated the lateral pterygoid muscle. In some cases, it terminated in the lateral pterygoid muscle. In others, it penetrated the muscle to join the anterior or posterior division of the mandibular nerve or its branches; thus, the variant nerve in such cases might be regarded as an additional root of the IAN. Because the concerned primordia of the nerves and muscles migrate extensively during development and growth, alternative routes of migration may bring about variants like the one under study. The variant appeared to be unique in some of its features. It may be a source of neuropathic and referred pain. Failure of the conventional inferior alveolar nerve block anesthesia and the peripheral neurectomy used for the treatment of trigeminal neuralgia may be partly due to the presence of this variation.