Nerve plexuses in the oral mucosa

Abstract

Oral nerve plexuses were studied in the mucosa of the tongue, hard palate, cheek and gingiva of rabbits, cats and monkeys. Whole thickness methylene blue preparations, frozen sections of tissue impregnated with silver and photographic reconstructions were used to assess the topographical arrangement and density of nervous plexuses. In the various regions a coarse submucous plexus and a much finer subepithelial network were identified, and these were associated with sensory nerve terminations. Plexus formations were found to have greatest density in the dorsum of the tongue, hard palate and gingiva, particularly in the anterior part of the mouth. Myelinated somatic fibres predominated in the plexuses but, from a consideration of nerve fibre diameters, it was concluded that autonomic fibres contribute to the formation of oral nerve networks. The findings lend further support to the view that sensory discrimination largely depends on a complex pattern of nerve impulses reaching higher centres.