title: Three-dimensional structure of Tomes' processes and enamel prism formation in the kitten.
abstract: The Tomes' processes of ameloblasts in the kitten were examined with both transmission and scanning electron microscopes and their three-dimensional structure demonstrated. In general, Tomes' process can be envisaged as the upper part of a diagonally cut column. It was established that the flat crescent face of the process which is slanted cervically, it is the secretory surface (S-face) and the curved crescent surface which is cuspally directed, is the nonsecretory surface (N-face). The cervical border of the S-face is confluent with the free apical surfaces of cervically adjacent ameloblasts. Only the S-face and the adjoining small part of the next ameloblasts produce enamel and arrange crystallites into prisms as evidenced by the perpendicular orientation of crystallites to the S-face of Tomes' process and the free ameloblast surface. Crystallite arrangement within prisms and prism arrangement within enamel are determined by the three-dimensional morphology of the Tomes' processes. The processes are schematically represented and their relationship to other ultrastructural features as seen in sections is discussed.
mesh_terms: D000565:Ameloblasts / Q000648:ultrastructure*; D000818:Animals; D002415:Cats; D003743:Dental Enamel / Q000648:ultrastructure*; D008854:Microscopy, Electron; D013499:Surface Properties