The aim of this study was to investigate the relationship between parameters of facial morphology, maximal voluntary mouth opening ability, and condylar movements in 21 adult females, aged between 20 and 24 years. The subjects had a normal occlusion without sign or symptoms of temporomandibular joint (TMJ) dysfunction. Mandibular movements were recorded using an opto-electric jaw movement recording system with six degrees of freedom under a series of maximal mouth opening-closing movements. Maximal jaw opening and coincident condylar movement were measured three-dimensionally. The mean values of the incisor and condylar path were 41.1 +/- 3.5 mm (range 35.6-50.9 mm) and 12.8 +/- 2.8 mm (range 8.1-19.2 mm), respectively. Although the positive correlation between maximal jaw opening and facial morphology was significant, none of the variables significantly differed between the value of the condylar path and facial morphology. The length of the path of maximum incisor movement and the condylar path during mandibular movement also did not correlate. Stepwise multiple regression analysis indicated a positive association between the maximal length of the incisor path and the cephalometric value of mandibular ramus inclination (R2 value was 0.369). The results of this study suggest that facial morphology size has a limited effect on maximal voluntary mandibular opening and condylar movements in normal adult female subjects.

Original paper Application of Thermography in Dentistry-Visualization of Temperature Distribution on Oral Tissues-Manabu KOMORIYAMA, Rie NOMOTO, Rin TANAKA1), Noriyasu HOSOYA2), Kazuhiro GOMI2), Fumiaki IINO2), Akihiro YASHIMA2), Yasuko TAKAYAMA3), Masahiko TSURUTA4), Hajime TOKIWA4), Kenzo KAWASAKI1), Takashi ARAI2), Toshio HOSOI3), Ayao HIRASHITA4) and Susumu HIRANO The purpose of this study was to devise and propose appropriate conditions for the photographing of thermal images in the oral cavity and to evaluate which thermography techniques can be applied to dentistry by evaluating the differences in temperature among oral tissues. Thermal images of oral cavities of 20 volunteers in normal oral condition were taken according to the guidelines of the Japanese Society of Thermography, with five added items for oral observation. The use of a mirror made it possible to take thermal images of the posterior portion or palate. Teeth, free gingiva, attached gingiva and alveolar mucosa were identified on thermal images. There were differences in temperature between teeth, free gingiva, attached gingiva and alveolar mucosa. These were nearly in agreement with the anatomical view. Thermography need no longer be restricted to the anterior portion using a mirror, and can now be applied to the dental region.

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Objective: To clarify whether the concept of main occluding area, where hard food is initially crushed, exists in patients who have a jaw deformity. Materials and Methods: Nineteen subjects with normal occlusion, 18 patients with mandibular prognathism, and 11 patients with mandibular prognathism who had undergone orthognathic surgery participated in this study. The main occluding area was identified by clenching Temporary Stopping. The coincidence, location of the main occluding area, and distance from the first molars to main occluding area were examined. Results: High coincidence of the main occluding area was obtained in all groups, signifying that the main occluding area exists even in these patients. Mandibular main occluding area was located on the first molar in all groups. Maxillary main occluding area in subjects with normal occlusion was located on the first molar. However, it was located on the second premolar and first molar in patients with mandibular prognathism, and on the first and second molars in patients with mandibular prognathism who had undergone orthognathic surgery. There was a statistically significant difference in distance from the maxillary first molar to the main occluding area among groups, but there was no difference in the distance from the mandibular first molar among groups. Conclusion: The main occluding area is more stable on the mandibular first molar than the maxilla in all groups. (Angle Orthod. 2016;86:87-93.)

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