The effect on the temporomandibular joint morphogenesis and its development by restriction of jaw movement in mice

2001 Fiscal Year Final Research Report Summary

• Project/Area Number: 12671935
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Surgical dentistry
• Research Institution: Shimane Medical University
• Principal Investigator: YOSHIMURA Yasuro School of Medicine, Shimane Medical University, Professor, 医学部, 教授 (50093480)
• Co-Investigator(Kenkyū-buntansha): NAITO Shinichi School of Medicine, Shimane Medical University, Senior Resident, 医学部, 医員 ; OBARA Seiji School of Medicine, Shimane Medical University, Lecturer, 医学部, 講師 (70204279)
• Project Period (FY): 2000 – 2001
• Keywords: Temporomandibular joint / Exo-utero development / Restriction of jaw movement / Growth factor

Research Abstract

By the maxillo-mandibular fixation, no significant systemic growth retardation of the embryo was not detected. But at the temporomandibular portion of the mouth movement restriction, the border between the cartilage of the condylar head and the calcified bone in the neck became unclear and diffuse macroscopically.
Deformed and disarranged cells were found in fee perichondrium of the condylar head, furthermore abnormal ossification was also observed between the proliferating and prehypertrophic zones and therefore discontinuity cell arrangement was characteristic. This finding suggested that jaw movement played an important role in the prenatal development of the temporomandibular joint. From the immunohistochemical staining and western blotting method of basic fibroblast growth factor (b-FGF) and its receptor (FGFR-3) revealed high stainability not in the superficial condylar chondrocytes but rather deeper proliferating and prehypertrophic zones at the embryonic day (E) 15.5, and E17.5. While in adults of both sex, b-FGF and FGFR-3 showed a high stainability in the superficial chondrocyte zone and gradually decreased towards to deeper zones. These molecules seemed to function in the mechanisms of calcification. Western blotting analysis of FGFR-3 in the normal growth showed a high stainability at the E 15.5, E 17.5 and at 11th day birth but in adult it revealed a weak stainability. B-FGF in the control group revealed a similar tendency but in adult at most little staining was observed.