Histology, Embryology and Gross Morphology of The Mandibular Dentition in Mule Deer

Abstract

Histologic development of the dentition of the mule deer, Odocoileus hemionus hemionus , is similar to that of other mammalian species. In the dentin the incremental lines and the lines of Owen appear to be the result of one or more of four factors: minute and simultaneous deviation of the dentinal tubules; slight bulges in the dentinal tubules with a localized flourish of branches; differential effect of transmitted or reflected light unaccompanied by variation in the dentinal tubules; interglobular dentin consistent with the incremental pattern. A thin layer of cementum is continuous over the crowns of the cheek teeth. The fibers of the periodontal membrane surrounding the incisors and canines are modified to compensate for the moment imposed upon them by their position. Blood sinuses are conspicuous by their numbers and extent in the periodontal membrane. Both the incisors and the canines are incisiform teeth; the deciduous and permanent second and third premolars are lophodont; the deciduous and permanent fourth premolar and the molars are selenodont. In the selenodont teeth, the enamel dips sharply, separating the cusps to a level deep within the crown. Although the crowns are somewhat hypsodont, these teeth are actually brachyodont.