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.

Cranial Nerves N‐VI

“…Finally, the inferior alveolar nerve can be doubled in its course from the mandibular canal unilaterally or bilaterally. This variation usually indicated the presence of accessory nerves (Anderson et al 1991;Buch and Agnihotri 2012;DeSantis and Liebow 1996).…”

“…The inferior alveolar nerve may travel through bifid mandibular canals that rejoin in the ramus of the mandible both unilaterally and bilaterally (Buch and Agnihotri 2012). A trifid mandibular canal has been observed in one study (de OliveiraSantos et al 2012).…”

“…The normal nerve supplying the lateral pterygoid is present in this variation (Buch and Agnihotri 2012). Another type of recurrent branch may course superficial or deep to the lower head of the lateral pterygoid muscle (Buch and Agnihotri 2012).…”

“…The normal nerve supplying the lateral pterygoid is present in this variation (Buch and Agnihotri 2012). Another type of recurrent branch may course superficial or deep to the lower head of the lateral pterygoid muscle (Buch and Agnihotri 2012). Further variation includes a recurrent branch communicating with the anterior division of the mandibular nerve arising just below the origin of the mylohyoid nerve (Buch and Agnihotri 2012).…”

“…Further variation includes a recurrent branch communicating with the anterior division of the mandibular nerve arising just below the origin of the mylohyoid nerve (Buch and Agnihotri 2012). One final variation includes a recurrent branch of the inferior alveolar nerve communicating with the posterior division of the mandibular nerve and rejoining with the proximal inferior alveolar nerve or auricotemporal nerve (Buch and Agnihotri 2012).…”