Occlusal Contact and Mechanosensitive Threshold in Patient with Uncomfortable Occlusion

Objectives: The purpose of this study is pursuing the pathogenesis in patients with uncomfortable occlusion. Methods: Firstly, in order to set the reference ranges for the periodontal mechanosensitive thresholds (PMT), 40 people with healthy teeth and jaws (26 males, 14 females, with a mean age of 25.3±2.6) who didn't indicate abnormal occlusal contacts in the intercuspal position (ICP) with the add-picture method were selected. Measurement of the PMT were performed using von Frey's hair (North Coast Medical). The reference ranges for the PMT were calculated by parametric methods. Secondly, six people (2 males, 4 females, with a mean age of 43.3±10.7) who came to our hospital complained of discomfort at time of occlusion were selected. Occlusal contacts in ICP were observed by add-picture method. PMT was measured in the abovementioned manner. The measurement of static and moving two-point discrimination thresholds (s-2PD, m-2PD) and the Semmes-Weinstein monofilament test were performed using 2-PD discriminator (North Coast Medical) and von Frey's hair. The measurement sites were upper and lower lips on both sides, mental, tongue, and index fingers of upper limbs. Results: The reference ranges of PMT were revealed respectively. No patient with uncomfortable occlusion indicated any simultaneous bilateral equal contact of molars. In addition, in comparison with the reference ranges of PMT, one patient with deviations on both maxilla and mandibular (group-A), one patient with deviations only on the maxilla (group-B), and four patients without any deviation from the reference ranges (group-C) were observed. Moreover, group-A indicated significant deviations from the reference ranges of s-2PD and m-2PD in all rami labiales superiors, labiales inferiors and mentales. group-B also indicated significant deviations from the reference ranges of s-2PD and m-2PD, but only in rami mentales. Conclusions: These results suggested that some patients with uncomfortable occlusion have perceptual problems.