Research for the Animal Models with Cranio-Facial Deformities

1991 Fiscal Year Final Research Report Summary

• Project/Area Number: 02670919
• Research Category: Grant-in-Aid for General Scientific Research (C)
• Allocation Type: Single-year Grants
• Research Field: 小児・社会系歯学
• Research Institution: Department of Dentistry, Tokyo Medical and Dental University
• Principal Investigator: OHYAMA Kimie Tokyo Medical and Dental University, Dentistry, Associate Professor, 歯学部, 助教授 (90014216)
• Co-Investigator(Kenkyū-buntansha): SIZUKI Shoichi Tokyo Medical and Dental University, Dentistry, Assistant, 歯学部, 助手 (90187732)
• Project Period (FY): 1990 – 1991
• Keywords: teratogen / alkylating agent / fetal surgery / rat

Research Abstract

General review of study achievements(Summarizing the final year-term)
This study was done in an object to research of an individual specific growth and development by producing an experimental animal with deformities originated from crania-facial hypoplasia.
Initially, the effect of inducing deformities with a teratogenic drug was tested and their deformed aspects were observed and growing after birth was discussed. In this study, the rat on day 13-15 was given an injection of alkylating agent. After macroscopic observation of the new bornes to identify their induced deformities, they were double stained and cleared for precise observation of deformed site. As results, some samples had cleft palate, small mandible and seemingly serious systematic organ deformities which did not survive them after birth.
Further, fetal surgery procedure were performed in the rat on day 17 of gestation in an object to produce deformity limited to their maxillofacial areas. After laparotomy, a fetus snout was exposed through a tiny hysterotomy, and its upper lip and maxillary alveolar area were burnt with a heated steelwire and then returned for suturing. After spontaneous delivery per vagina, the litter was examined to identify the operated and control newbones. No difference was found in body structure, weight and behaviour between the operated and control newbornes except artificial cleft lip in the operated newbones. Histological observation in the operated newbones revealed partial defects in maxillary bone, alveolar bone and upper incisal tooth germ, as well as partially nasal and oral communication.
These results were indicated available for certain of cleft lip animal model. The operated pups did not do sucking and died in two days after birth but an artificial incubation seemed possible. Therefore, this method was considered valid in future to use for researching growth and development of an experimental animal with craniofacial deformities.