Correlation Between Temporomandibular Joint Morphology,Condyle Position And Dento-maxillofacial Morphology

Objective In this study,cone-beam CT(CBCT)and Dolphin software were used to measure and analyze the morphological characteristics of temporomandibular joint and dentofacial in adult malocclusion patients,to study the correlation between the morphology of temporomandibular joint,condylar process position,dento-maxillofacial morphology and masticatory function morphology,and to explore the correlation between the morphology and structure of temporomandibular joint and orthodontic treatment,so as to guide the diagnosis and treatment of clinical orthodontics.Methods 50 adult patients with malocclusion,including 32 females and 18 males,with an average age of 24.4 ± 6.1 years(18-45 years).CBCT taken before orthodontic treatment and lateral cephalograms formed by Dolphin software were taken as research objects,and the morphology and structure of temporomandibular joint and dento-maxillofacial morphology were measured by Dolphin software.Bilateral anterior joint space,superior joint space,posterior joint space,joint fossa depth and joint nodule inclination were measured on sagittal joint images,and bilateral external joint space,medial joint space and internal joint space were measured on coronal joint images.The vertical and sagittal correlation indexes and chewing function and morphology related indexes were measured on lateral cephalograms.All data were analyzed by SPSS 25.0 statistical software.Results 1.There was no significant difference between the left and right temporomandibular joint morphology and condyle position(P>0.05).2.There was no significant difference in temporomandibular joint morphology and condyle position between male and female(P>0.05).3.As for the relationship between temporomandibular joint morphology,condyle position and dento-maxillofacial morphology,the superior joint space was negatively correlated with MP-SN.Anterior joint space was positively correlated with ANB.The inclination of joint nodule was positively correlated with MP-OP,PP-MP,ANS-Me/Ar-Go,ANB,Wits,and negatively correlated with SNB.There was a negative correlation between the external joint space and the tangent angle.4.In this study,the condyles of the samples located in the anterior part of the articular fossae were 6%,the median part were 64%,and the posterior part were 30%.Conclusion 1.The condyle position was correlated with the dento-maxillofacial morphology.Compared with other types of malocclusion,the condyles of patients with high angle skeletal Class Ⅱ malocclusion were more posterior and superior in the sagittal direction of the articular fossae.2.The morphology of temporomandibular joint had a great correlation with dento-maxillofacial morphology and structure.Compared with other types of malocclusion,patients with high angle skeletal Class Ⅱ malocclusion had greater condylar leading inclination.3.The position of condyle was correlated with the shape of masticatory function.The greater incisor lead inclination,the more lateral the condyle was in the coronal direction of articular fossa.4.The results of this study can be used as a reference for clinical evaluation of temporomandibular joint morphology and condyle position in patients with malocclusion.When designing orthodontic treatment plan and carrying out treatment,whether there are symptoms and signs related to temporomandibular disorders or not,we should pay close attention to the morphology of temporomandibular joint and condyle position.For patients with high angle skeletal Class Ⅱ malocclusion,lowering posterior teeth and extraction treatment can be considered to compensate for poor occlusal plane inclination and improve condylar position.During the treatment,the occlusal plane should be carefully controlled to avoid clockwise rotation of mandible or elevation of posterior teeth.