〔Abstract〕 Objective To study the correlation between occlusal contacts from over-erupted third molar and temporomandibular disorders(TMD). Methods 45 patients with TMD were selected as experimental group: 15 cases(group A) with unilateral mandibular third molar over-eruption, 15 cases(group B) with unilateral maxillary third molar over-eruption, 15 cases(group C) with unilateral mandibular and the contralateral maxillary third molar over-eruption, and 15 cases with normal occlusion as control group. Data of occlusal contacts were recorded with T-scan Ⅲ. Craniomandibular index(CMI), visual analogue scale(VAS) and mandibular motor function before and after the extraction were evaluated. Results In each experimental group, the movement of center of force increased, and the closure time, lateral disclosure time and protrusive disclosure time were longer than those in the control group(P<0.05). The asymmetry index of contact in each experimental group increased(P<0.05). The incidence of premature contact, protrusive interference and lateral interference in each experimental group were significantly higher than those in normal control group(P<0.05), and there was no significant difference in the incidence of premature contact and lateral interference between experimental group and control group after extraction(P<0.05). The CMI and VAS of TMD patients decreased significantly 1 month after the extraction.The maximum vertical opening, protrusive and lateral distance increased(P<0.05). Conclusion Bilateral occlusal symmetry and balance are poor in patients with third molar(s) over-eruption. Occlusal interference caused by the over-erupted third molar(s) is closely related to the clinical symptoms of TMD. Removing the over-erupted third molar(s) can better improve the opening type and vertical opening of the patients with TMD, and relieve the joint noise and pain to a certain extent.