Headache

AFFERENT impulses from the teeth are carried by branches of the second and third divisions of the fifth cranial nerve. Through the apex of the tooth, nerves enter the pulp accompanying the larger vessels and form an almost complete mantle around the arteries.¹Vascular walls in the tooth pulp are innervated by unmyelinated fibers. Nerve fibers from the tooth pulp form a complicated network between the odontoblasts and then pass into the partially calcified layer of the dentine, and sometimes into the inner margin of the calcified dentine itself²(fig. 1). Brashear³found that the pulp nerves in human teeth contain more than 50 per cent of unmyelinated and small myelinated nerve fibers less than 6 microns in diameter. The rest vary in size up to 10 microns. No pulp fibers were found to be more than 10 microns in diameter. He observed that thermal, mechanical or