A SCANNING ELECTRON-MICROSCOPIC STUDY OF DEVELOPING HUMAN DECIDUOUS ENAMEL ON THE DEPENDENCE OF THE OUTLINE OF SURFACE PITS ANGLE OF OBSERVATION

On the developing enamel surfaces of fetal human deciduous teeth, many of the surface pits were arcade-shaped with the arcade preferentially pointing in a cervical direction. The configuration of the interprism ridges between the pits contributed to this appearance. Surface crack s allowed verification of an incisal inclination of the subsurface pri sms. This apparent paradox was solved when the specimens were tilted s o that the pits were viewed in the direction of the prisms, giving the pits a compressed arcade-shape with the arcades pointing incisally. I t is recommended that care should be exercised and due attention paid to the angle of observation when determining the orientation of pit ar cades. Pit entry direction seems to be a more reliable feature for inf erring the direction of tangential ameloblast movement. (C) 1998 Elsev ier Science Ltd. All rights reserved.