[Expressions of calcitonin gene -related peptide in rats with occlusal reconstruction]

To investigate the expressions of calcitonin gene-related peptide (CGRP) in rats with occlusal reconstruction.

30 Wistar male rats were randomly divided into 3 experimental groups and 3 control groups, 5 rats in each group. The molar of the right maxilla and mandible of rats in the experimental groups were ground to the gingival level without occlusal contact. The occlusal contact was recovered by stopping grounding molar of the rats in two of the experimental groups. The section of the disc and articular capsule Was subject to immunohistological study to evaluate the expressions of CGRP by using SABC method. Light microscope and microscopic photo analytic software were employed to detect calcitonin gene-related peptide-like immunoreactive (CGRP-LI) nerve fibers in frozen section of TMJs in 30 rats. SPSS10.0 software package were used for statistical analysis.

The areas of CGRP-LI nerve fibers in unilateral chew group were significantly larger than those in the control group (P < 0.01, P < 0.05). The increment in the non-chewing side was significantly higher than that in the chewing side (P < 0.05). There was no significant difference in the areas of CGRP-LI nerve fibers between the early occlusal reconstruction group and the control group (P > 0.05) and there was no significant difference between the non-chewing side and the chewing side (P > 0.05). There was significant difference in the areas of CGRP-LI nerve fibers between the later occlusal reconstruction group and the control group (P < 0.01), while no significant difference was found between the non-chewing side and the chewing side (P > 0.05).

The expressions of CGRP can recover normal in early occlusal reconstruction but not in later occlusal reconstruction.CGRP might participate in the histopathogenesis of temporomandibular joint disorders. Supported by Research Fund from Science and Technology Bureau of Taian City (Grant No.2003-52).