Characteristics of periodontal mechanoreceptors supplying reimplanted canine teeth in cats.

These characteristics were investigated 12 weeks and one year after tooth reimplantation. Electrophysiological recordings were made from single mechanosensitive units dissected from the inferior alveolar nerve and each unit was characterized by applying forces to the crown of the tooth. The characteristics were compared with those of receptors innervating normal teeth. The periodontal mechanoreceptors supplying teeth reimplanted 12 weeks earlier responded to applied forces over a narrower range of directions, had higher force thresholds, lower discharge frequencies and adapted more rapidly than controls. One year after reimplantation their characteristics were nearer to normal but they remained significantly different from those of control units. It seems likely that the altered receptor characteristics could have resulted from a combination of changes in tooth mobility, disorganisation of the collagen matrix and direct injury to the nerve terminals.