The formation of Sharpey's fibres in the hamster under nonfunctional conditions

Abstract

Mandibular second molar buds from 2-day-old hamsters were transplanted subcutaneously to the cheek area of adult hamsters and allowed to develop for 28 days. Tooth size and shape were consistent with those of control animals. Those elements derived from the dental papilla, namely the cementum, dentine and pulp cavity, were essentially normal; however, there was generally a lack of enamel formation. In addition to development of the tooth, a periodontal ligament and shell of alveolar bone formed around the roots of the tooth. Sharpey's fibres were found inserting into the cementum of the external root surfaces, and these fibres were continuous with the principal fibre bundles of the periodontal ligament. No Sharpey's fibres were found inserting into the cementum or alveolar bone in the apical or interradicular areas. Sharpey's fibres do form under nonstress or nonfunctional conditions, and are not completely dependent on external forces for their development.