Changes with age in canine tooth pulp-nerve fibres of the cat.

Light microscopical observations have been made on teased pulpal nerve fibres from mandibular canine teeth of cats aged 3 years or more. Both internodal lengths and external fibre diameters appeared to be reduced compared to the young adult. Qualitative myelin sheath changes were commonly observed. These consisted of extremely short, smooth or distorted intercalated internodes, myelin wrinkling, nodal lengthening and formation of myelin ovoids. Features suggesting de-myelination were also present. These findings should be considered when functional aspects of pulpal axons in the ageing tooth are discussed.