Details of the intralingual topography and morphology of the lingual nerve

The lingual nerve supplies the tongue with trigeminal sensory fibers and sensory fibers that originate from the chorda tympani. The aim of this study was to investigate, by dissection, the anatomical features of the lingual nerve at the level of the tongue and to correlate the findings with existing data. Six human adult cadavers dissected bilaterally and 6 specimens of tongue–pharynx–larynx from autopsied adult cadavers were studied. The lingual nerve gives off its terminal branches at the anterior border of the hyoglossus muscle where the anastomotic loops between the lingual and hypoglossal nerves are found. Two morphological types of terminal division of the lingual nerve were seen: a single primary trunk or two primary trunks, a medial one distributed in the middle third of the tongue and a lateral one for the anterior third of the tongue. The primary terminal branches of the lingual nerve were located on the outer surface of the genioglossus muscle, forming a nervous layer over the deep artery of the tongue. The following emerged from the primary trunk(s): thin branches for the ipsilateral mucosa of the ventral surface of the tongue and 4–9 thick secondary trunks, with palisade disposition and translingual courses that followed the outer surface of the genioglossus muscle towards the dorsal mucosa of the ipsilateral part of the tongue, anterior to the circumvallate papillae.