Abstract:

Objective To investigate the differences of condylar position in patients with temporomandibular disorders(TMD), and to further explore the effects of condylar position displacement and malocclusion factors on TMD. Methods According to the inclusion criteria, normal occlusion subjects without TMD(group A, n=10), normal occlusion subjects with TMD(group B, n=8), malocclusion subjects without TMD(group C, n=9) and malocclusion subjects with TMD(group D, n=20) were collected. Condylar position measurement(CPM) and Cadiax Ⅳ were used to locate the position of condyle in RP and ICP, and the displacement and direction of condyle in three-dimensional direction from RP to ICP were measured by vernier caliper. All the data were averaged three times and analyzed by SPSS26.0 statistical software. Results In the sagittal direction, the condylar displacement of group A and group B, group C and group D, and group A and group D had statistical differences(P<0.01). The displacement of the right condyle in the vertical direction of group D was greater than that of group A, and the difference was statistically significant(P<0.05). The difference among other groups was not statistically significant. There was no significant difference in the lateral displacement of condyle between the four groups. In group A and group D, the largest proportion of condyle deviation was anterior up, while in group B and group C, the largest proportion of condyle deviation was posterior up. Conclusion RP-ICP condylar sagittal displacement is common in people with TMD. The condyle displacement of RP-ICP in malocclusion patients without TMD is not significantly different from that in normal occlusion patients without TMD. Patients with TMD malocclusion are more likely to have condylar displacement in sagittal direction and vertical direction than normal occlusion without TMD.

Key words: temporomandibular disorders, jaw position, condylar position displacement