An Experimental Study on the Change of Autonomic Function under Occlusal Interference

I. The Change of Blood Pressure Induced by Unilateral Bite-Raising

抄録

Effects of occlusal interference on blood pressure were examined in 47 unanaethetized rats. The occlusal interference was produced by insertion of unilateral bite-raising splints (1, 2 or 3 mm in vertical dimension). The splints were set on the upper teeth for 20 days. The systolic blood pressure was measured from the caudal artery by the tail-cuff method before, during and after insertion of the splints. The blood pressure of the 1 mm unilateral bite-raising group did not change significantly between before and during insertion of the splints. In the 2 and 3 mm bite-raising groups, the blood pressure during insertion of the splints increased significantly as compared with that before insertion of the splints; after removal of the splints, the increased blood pressure returned to the pre-insertion level. Reproducibility in the increase of blood pressure was observed when the insertion of the splints was applied repetitively. Unilateral bite-raising also produced a statistically significant reduction of body weight during insertion of the splints. However, when the effect of fasting on the blood pressure was examined, the blood pressure did not change significantly, whereas the body weight decreased remarkably during fasting. This indicates that the increase of blood pressure depends primarily on unilateral bite-raising. The results of the present study suggest that activation of the autonomic nervous system is involved in the increase of blood pressure induced by insertion of unilateral bite-raising splints, and that occlusal interference activates the autonomic nervous system as a stressor.