Analysis Of The Patients With Temporomandibular Disorder Accompanied By Deep Overbite Evaluated With Cone-beam Computed Tomography

Objective:To identify differences in temporomandibular morphology and joint space between subjects with temporomandibular disorder accompanied by deep overbite and individual normal occlusion subjects by cone-beam CT.To investigate the morphological characteristics of temporomandibular disorder accompanied by deep overbite.To discuss the role of deep overbite in TMD and provide references for diagnosis and early prevention for TMD.Methods:30 subjects who were diagnosed with TMD with anterior teeth deep overbite in were chosen as the experimental group.30 individual normal occlusion subjects with healthy temporomandibular joints were chosen as the control group.Both subjects of the experimental group and the control group were selected to scan the TMJ areas with New Tom 5G CBCT.NNT-Viewer software was used to process and reconstruct the CT images.Chose axial,saggital and coronal planes as measuring planes.SPSS 19.0 software was used to analyze the data statistically.Results:1.No significant differences were found between the TMJs of the right and left side of the individual normal occlusion group.2.In experimental group,the average depth of glenoid fossa of the right TMJ was 8.76 ± 0.87mm,the average depth of glenoid fossa of the left TMJ was 8.35 ±1.01mm.And there were statistically significant differences in height of glenoid fossa of bilateral TMJs(P<0.05).Other statistics of the bilateral TMJ showed no significant differences.3.When used Vitral methods,the average anterior joint space of the control group was 2.01 ± 0.65mm,while the average anterior joint space of the experimental group was 2.37 ± 0.60mm,and the difference was statistically significant(P<0.05).The average superior joint space of the control group is 3.04±0.65mm,while the average superior joint space of the experimental group was 2.55 ± 0.62mm,and the difference was statistically significant(P<0.05).The average posterior joint space of the control group was 1.91 ±0.69mm,while the average posterior joint space of the experimental group was 1.64 ±0.42mm,and the difference was statistically significant(P<0.05).When used Zhang Zhenkang methods to measure TMJ joint space,the average anterior,superior,posterior joint space of the control group were 2.09±0.66mm,3.05 ± 0.67mm,2.06 ± 0.70mm respectively.The average anterior,superior,posterior joint space of the experimental group were 2.50 ±0.62mm,2.56 ±0.94mm,1.81±0.47mm respectively.All measures between the control group and the experimental group were statistically significant(P<0.05).In the experimental group,anterior joint space were significantly higher than the control group(P<0.05),but superior joint space and posterior joint space of were significantly lower than control group(P<0.05).Conclusion:The positions and morphology of bilateral condyles were relatively symmetry in individual normal occlusion group.There were morphological differences of the bilateral TMJs of the experimental group.Position of condyles of patients with TMD accompanied by deep overbite tends to be superior and posterior.The changes of bone structure and joint space can be well showed by CBCT.