2012 Volume 18 Issue 2 Pages 139-151
Purpose : Periodontal mechanoreceptors sense the temporal, spatial, and intensive characteristics of forces exerted on the teeth. These characteristics contribute to the efficient control of jaw movement during mastication. The purpose of this study was to investigate the relationships between the periodontal tactile sensations of the lower premolars and molars and the occlusal loading conditions of the teeth.
The mandibular premolars and molars of 16 healthy adult male volunteers (25.8 ± 1.4 years old) with complete dentition were examined. The tactile detective threshold (TDT) of each tooth was determined using calibrated monofilaments (von Frey hairs). The occlusal force (OF) on each tooth at maximal voluntary clenching was measured with a pressure sensitive film. The occlusal contact area (OCA) of each tooth at the intercuspal position was registered with a silicon check-bite. The OF and OCA distributions for each tooth were calculated as a ratio to the total value on the mandibular arch. Preferred chewing side and main occluding area were determined by using cotton rolls and temporary filling materials, respectively.
The mean TDTs increased from the most anterior to the most posterior tooth. TDTs of the premolars were significantly smaller than those of the molars, although there were no differences between the first and second premolar, or between the first and second molar. The mean TDTs of individual subjects showed no significant correlation with total OFs or total OCAs. In any type of tooth, there was no significant positive correlation between TDT ratios and OF or OCA, although the regression lines between TDT ratio and OF distribution, and between TDT ratio and OCA distribution were diagonally right up. TDTs of the teeth in all directions on the preferred chewing side were significantly higher than those on the contralateral side. TDT of the tooth (molar) included in the main occluding area was significantly lower than that of adjacent molar on the ipsilateral side.
These results indicate periodontal tactile sensation is more closely related to the preferred chewing side and the main occluding area than OF and OCA, which suggests that periodontal tactile sensation might be modified by the functional loading conditions relating with the frequency and magnitude of the occlusal loads during mastication.
