| Objective:Bone classⅡ,division 1,is a common malocclusion in clinical practice,and the three-dimensional growth and development of condyle has an important influence on the formulation of orthodontic treatment plan and the outcome of treatment.In this study,the three-dimensional structure of temporomandibular joint was measured by CBCT,and the position and morphological changes of condyle process between different growth and development stages and different sexes were studied,providing a more sufficient theoretical basis for clinical treatment.Methods:A total of 60 cases with ClassⅡ-1 classification without temporo-mandibular joint disease were selected,including 30 males and 30 females aged 11-16 years old,and were divided into pre-peak growth(15 males and 15 females)and post-peak growth(15males and 15 females)groups according to the quantitative stage method of cervical bone age.CBCT was taken and analyzed by Mimics 17.0 software in both groups to measure the morphology and position of condyles.Statistical analysis software SPSS 25.0 was used for data analysis,and independent sample T-test,paired sample T-test and chi-square test were used to compare the differences of sample data.Results:1.Bilateral condylar symmetry analysis:In this study,paired T-test was performed on the symmetry of the left and right temporomandibular joint of the included subjects,and it was found that there was no statistical significance between the measurement indicators(P>0.05).There was no significant difference in the morphology and location of condyle in both temporomandibular joint.2.Analysis of gender differences:before the peak of growth and development,the long axial diameter,anteropodylar diameter and condylar head width of male patients were all larger than those of female patients;the anterior articular space of male patients was smaller than that of female patients,and the posterior articular space was larger,with statistically significant differences(P<0.05).After the peak of growth and development,the length of the condyle axis,the depth of the articular fossa,the height of the condyle head,the supracondylar space,the anterior articular space and the posterior articular space in male patients were all larger than those in female patients,and the differences were statistically significant(P<0.05).There was no sex difference in slant degree and fossa width after articular nodule.3.Morphological differences of condyle between growth and development stages:after the peak of growth and development,the longitudinal diameter of condyle,the height of condyle head,the depth of articular fossa,and the width of the articular fossa were larger than those before the peak of growth and development,with statistically significant differences(P<0.05).After the growth peak,the anterior and posterior diameter of the condyle increased and the supracondylar space decreased compared with that before the growth peak,and the difference was statistically significant(P<0.05).There was a statistically significant difference(P<0.05)between the post-tubercular and post-tubercular slopes after the peak growth and development.4.Difference in condylar position between growth and development stages:more condylar positions were in the posterior position before the peak of growth and development,and more condylar positions were in the anterior position after the peak of growth and development,and the difference was statistically significant(χ~2=6.172,P=0.046).Conclusion:1.Male joint space is larger than female.2.After the peak of growth and development,the long axial diameter of the condyle,the height of the condyle head and the depth of the articular fossa in male patients were all larger than those in female patients3.Male condyles have more vertical growth than female condyles.4.After the peak of growth and development,patients with condyle in the anterior position tend to be more,so it is necessary to restore the normal position of condyle before orthodontic-orthognathic combined treatment. |
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