Three-dimensional Measurement And Analysis Of Mandibular Growth And Development In Malocclusion Patients With Different Cervical Bone Ages

Objective:To investigate the three-dimensional changes of mandibular growth in patients with skeletal class Ⅰ and Ⅱ malocclusion at different growth stages by using cervical vertebral age staging method,and to predict the trend of mandibular growth in patients with skeletal class Ⅰ and Ⅱ malocclusion at different cervical bone ages,so as to provide reference for early clinical diagnosis and treatment..Methods:A total of 160 untreated patients aged 6-18 years with malocclusion were enrolled.Lateral cephalograms and cone-beam computed tomography(CBCT)were taken at the same time,including 80 patients in skeletal class Ⅰ mean angle group and 80 patients in skeletal class Ⅱ mean angle group.SPSS 26.0 software was used for statistical analysis.Results: The mandibular measurements in different cervical spine bone age groups with Class Ⅱ mean Angle were lower than those in class Ⅰ mean Angle group.The coronal condylar distance at QCVM1 stage,QCVM2 stage and QCVM4 stage was statistically significant(P < 0.05),and the sagittal mandibular length and mandibular body length at QCVM3 stage and QCVM4 stage were statistically significant(P < 0.05).The mandible of patients with bone class Ⅱmean angle group showed an increasing trend with the maturation of cervical vertebra,but the increase was less than that of patients with bone class Ⅰ mean angle group,and there was statistical significance in the sagittal mandible length,mandibular body length,vertical ascending rami height and coracoid process length,and coronal mandible width(P< 0.05).The width of medial condyle,mandibular surface area and mandibular volume were statistically significant(P < 0.05).Conclusions:The growth of mandible in skeletal Class Ⅰ mean angle group was greater than that in skeletal Class Ⅱ mean angle group at the same cervical bone age,mainly reflected in the sagittal and coronal growth.The mandible of skeletal Class Ⅰ and skeletal Class Ⅱ mean angle groups showed an increasing trend at different cervical spine bone ages.The position of condyle in the glenoid fossa was different in skeletal Class Ⅰ and skeletal Class Ⅱ mean angle patients with different cervical spine ages.