The Study On Symmetry Of Temporomandibular Joint In Patients With Mandibular Asymmetry Including Curvature Analysis

Objective: To investigate the symmetry of bilateral temporomandibular joints in patients with mandibular asymmetry by cone beam computed tomography(CBCT).The mandibular condylar symmetry,bilateral condylar position and construction of bilateral glenoid fossa,all these three aspects were analyzed to compare the morphological characteristics of bilateral temporomandibular joint,and to investigate the effects of mandibular asymmetry on the bilateral temporomandibular joint.Methods: 35 patients with mandibular asymmetry were included as a study group,and 30 normal patients were selected randomly as the control group.Both groups were scanned by Planmeca(Finland)CBCT.Mimics 19,Geomagic,CATIA and other software were used to perform 3D reconstruction and analyze the image.The volume,surface,curvature of the condyles,and the inclination of the anterior and posterior slops of the condyles were measured to study the structure of the condyles.The curvature,height and the inclination of the anterior and posterior slops of the glenoid fossa were used to study the structure of the glenoid fossa.The measurement of the widths of joint space was used to evaluate the position of the condyle.Results: 1.The difference of condlys between deviation and nondeviation side were statistically significant(p<0.05).Compared with the control group,the volume,surface,curvature of the anterior and posterior slopes,and the inclination of the anterior slope of the condlye in nondeviation side were larger than those of the normal population(p<0.05).whereas the inclination of the posterior slope of the condyles in nondeviation side was smaller(p<0.05).2.The bilateral glenoid fossa in patients with mandibular asymmetry was basically symmetrical.Compared with the normal population,the height of the articular eminence in patients with mandibular asymmetry was significantly higher than that in the normal population(p<0.05).3.In mandibular deviation group,the anterior joint space of the deviation side were significantly greater than that of the nondeviation side,while the superior and posterior joint space were smaller(p<0.05).Compared with the normal population,the condylar position of the deviation side was posterior,and the condylar position of the nondeviation side was anterior(p<0.05).Conclusion: Construction and position changes caused by mandibular asymmetry of the condyles was more obvious than that of glenoid fossa.Compared with the normal population,changes of deviation side was greater than that of the nondeviation side.The condylar position of the deviation side was posterior,and the condylar position of the nondeviation side was anterior and inferior.