Abstract
The usefulness of thermography to one method in the diagnosis of the temporomandibular joint dysfunction (TMD) was evaluated in this study. Thirty-six subjects were divided into three groups: the control group without TMD, a TMD group with unilateral joint sound and a TMD group with unilateral joint pain. Each group consisted of twelve subjects The skin surface temperature on the temporal (TA), masseter (M), sternocleidomastoid muscles and the temporomandibular joint (TMJ) were measured by the thermographic technique at the rest position of the mandible and the period of chewing. The subjects were also examined for mandibular movement and an electromyography. In addition, the blood flow in the TMJ was observed by using a magnetic resonance imaging (MRI). The results were as follows; 1. In the control group, the difference between right and left skin surface temperature at the rest position of mandible was not significantly recognized, in comparison with those of the joint sound group and the joint pain group.2. In the control group, the difference between right and left skin surface temperature at the rest position of mandible by the existence of habitual chewing did not show any significant difference in the TA and M. In the joint sound group and the joint pain group, there was no significant difference between the region of signs and habitual chewing side.3. There was no significant difference between skin surface temperature on the TMJ and the quantity of the blood flow in the interior TMJ using MRI.4. The temperature peak in the region of M during chewing was significantly lower in that of the joint pain group than that of the control group. Therefore, the temperature peak in the region of M during chewing might be useful as a diagnostic method of TMD.5. The coincidence of time until the right and left temperature reached a maximum temperature was not significantly lower in those of the joint sound group and the joint pain group than that of the control group. Furthermore, the time from the start of chewing to the temperature peak was significantly longer in the symptomatic region in the joint pain group than that in the control group. These results suggest that the coincidence of time until the right and left temperature reached a maximum temperature and the time from the start of chewing to the temperature peak might be useful to diagnose TMD.
