Prenatal Development of Incisors in the Egyptian Buffalo (Bos bubalis)

Abstract

Objective: The teeth play important roles in food mastication, prehension and defense against predators. Although several studies demonstrated the development of teeth in different mammalian species, no data are, to our knowledge, available in Egyptian buffalos. Therefore, the present investigation was conducted to study the development of incisor teeth in buffaloe. Design: Descriptive study. Animals: seventeen buffalo embryos and fetuses of both sexes were used. Their crown vertebral rump lengths (CVRL) ranged from 2 to 46 cm (equivalent to 38 - 177 days old). Procedure: Embryos and fetuses were fixed in 10% neutral buffered formalin and decalcified by 14% EDTA solution for several weeks. The samples were dehydrated, cleared and embedded in paraffin wax using standard techniques. Sections were cut on Leitz microtome and mounted on uncoated slides. For general histological structure, a selection of slides was routinely stained with haematoxylin–eosin and examined by the light microscope. Result: The present study reported for the first time that the prenatal development of incisors in buffalo passes through three sequential stages: the bud, cap and bell stages. Although each stage was easily differentiated based on its form and its distinct developmental features, the three stages were overlapped with each other’s. Generally, the bud stage was observed in 11 cm CVRL buffalo fetuses, meanwhile the cap and bell stages were detected in 23 cm and 30 cm CVRL fetuses respectively. Conclusion and clinical relevance: These results can be used as inductive index for determination of the ages of buffalo embryos and fetuses.

Prenatal and postnatal development of the New Zealand white rabbit (Oryctolagus cuniculus) teeth: An emphasis on histological and computed tomography aspects

“…Likewise, the teeth appeared rst on the 19th day of prenatal embryonic age (E19), as an ectodermal epithelial thickening on each side of the entrance opening to the mouth consisted of undifferentiated epithelium cellular collections that represented the rst sign of tooth development in rabbits. These obtained results came in agreement with [29] in 2cm CVRL in the Egyptian buffalo embryos and with [30] in the molecular determinants of mouse tooth development. In the interim [31], expressed that, the rst tooth appeared in the jugal region at 16-day prenatal embryo life (E16), the bud stage appeared from 17-19-day prenatal embryo age (E17-19), the cap stage on 20-day prenatal embryo age (E20), the early bell stage at 25-day prenatal embryo age (E25), and the late bell, the cusps on 28-30-day prenatal embryo age (E28-30), and the beginning of dentinogenesis, amelogenesis, and cementogenesis from 15 to 30.…”

“…The enamel consisted of three layers: the external and internal enamel epithelium and the stellate reticulum. These perceptions match [29] in 11 and 21 cm CVRL buffalo embryos. Our ndings at 23-day prenatal embryonic age (E23) demonstrated that the typical tooth structure is formed from the enamel layer, the dentin, and the pulp cavity, which are surrounded by trabecular bony plates of the maxilla and mandible (which appear within the alveolar bone, either the maxillary bone or the mandible).…”