Sympathetic Adrenergic Innervation of Permanent Teeth in the Monkey (Macaca Irus)

Abstract

In the young monkey the incisors, canines, premolars and molars from the upper and lower jaws were sympathetically innervated. An adrenergic ground plexus was observed mainly around arterioles, but never all of the arterioles in a pulp were supplied with sympathetic nerve terminals. There was no essential variation in the studied innervation at the different stages of apex closure. In aged teeth the pulpal sympathetic innervation was reduced. This seemed not to be entirely associated with diminished vascularization. The results support earlier suggestions that sympathetic adrenergic nerve fibres are present in all the permanent teeth of many of the higher mammals including man. The possible patho-physiological role of adrenergic innervation in the dental pulp was discussed. Special attention was paid to a proposed connection between the vasoconstrictor innervation and the unusually high tissue fluid pressure in dental pulp.