Correlation Between Temporomandibular Joint Morphological Structure And Occlusal Characteristics In Adults With Skeletal Class Ⅰ Malocclusion

Purpose:In this study,cone-beam computer tomography(CBCT)and Mimics Medical20.0 software are used to measure the morphological data of temporomandibular joint(TMJ)in adults with skeletal classⅠmalocclusion,analyze the correlation between TMJ morphology and tooth occlusal characteristics,and explore whether different tooth occlusal characteristics will affect the morphological structure of TMJ.Methods:A total of 69 volunteers in line with the study design were strictly screened,and each volunteer had CBCT and lateral cephalogram taken.The CBCT images were stored in DICOM format and imported into Mimics Medical 20.0 software for three-dimensional reconstruction of equal proportions.The reconstructed condyle surface area and volume were calculated after head position was adjusted.The layer with the maximum transverse area of the axial epicondyle was selected as the cross section,and the oblique sagittal plane and oblique coronal plane of the condyle center were intercepted on this plane as the reference plane for measurement.The maximum axial area of the condyle、long axis of the condyle、minor axis of the condyle、condylar axis angle were measured in cross section.Superior space、anterior space、posterior space、height of the fossa、width of the fossa、articular eminence inclination、anterior inclination of the condyle and posterior inclination of the condyle were measured on the oblique sagittal plane of condyle center.Medial space、central space、lateral space、medial inclination of the condyle and lateral inclination of the condyle were measured on the oblique coronal plane of condylar center.Uceph-4.2.1 software was used to measure the incisal guidance angle,the occlusal plane angle,overbite,overjet and mandibular plane angle.All data were analyzed by IBM SPSS Statistics25.0 software.Results:There was a certain correlation between TMJ morphological structure and tooth occlusal characteristics:1.The condyle volume,condyle surface area,long axis of the condyle,medial space and central space of the sample were negatively correlated with the occlusal plane angle.The anterior joint space was positively correlated with the occlusal plane angle.2.The condylar axis angle was negatively correlated with the incisal guidance angle.The anterior space,articular eminence inclination and anterior inclination of the condyle were positively correlated with the incisal guidance angle.3.Condylar axis angle was positively correlated with overbite.4.There was a negative correlation between anterior space and overjet.Conclusion:There was a certain correlation between TMJ morphological structure and tooth occlusal characteristics:1.The larger the incisor guide angle,the larger the anterior articular space,the steeper the anterior slope of condyle,and the steeper the articular tubercle morphology.2.The steeper the occlusal plane,the larger the anterior joint space and the smaller the condyle volume.3.The larger the covejet,the smaller the anterior joint space;4.The larger the overbite,the smaller the angle between the long axis of the condyle and the sagittal axis.