Abstract
In order to develop an objective evaluation for the stability of the masticatory movement path in patients with temporomandibular disorders (TMD), 20 healthy subjects and 20 TMD patients were asked to masticate three types of food with varying textures. A piece of chewing gum, one peanut, and a slice of crispy bread were used as test foods. The movement of the incisal point while masticating the test food for 10 seconds on the habitual side was recorded. Ten cycles beginning with the fifth cycle of mastication were analyzed. The stability of the masticatory movement path was determined by calculating the SD/OD (standard deviation/opening distance) of the opening lateral component, closing lateral component, and vertical component. All results were compared between the healthy subject group and the TMD patient group. The masticatory movement path of the healthy subject group was more stable than that of the TMD patient group for all test foods. There were significant differences between the two groups in the opening lateral component (gum: t=4.78, p<0.01, peanut: t=3.73, p<0.01, bread: t=2.60, p<0.05), closing lateral component (gum: t=4.37, p<0.01, peanut: t=2.61, p<0.05, bread: t=2.97, p<0.01), vertical component (gum: t=6.25, p<0.01, peanut: t=3.15, p<0.01, bread: t=2.57, p<0.05) respectively. These results confirmed that the masticatory movement path of TMD patients is less stable than that of healthy subjects.
