Cone-beam Computed Tomography Assessment Of Mandibular Asymmetry In Unilateral Cleft Lip And Palate Patients In Mixed Dentition Period

Objective:To analysis whether there is any difference between the unilateral cleft lip and palate(UCLP)and non cleft lip and palate(CLP)patients in mixed dentition period by measuring cone-beam computed tomography(CBCT)image data.To estimate the symmetry\position and reasons.The aim of the study is to provide the theoretical basis and support for orthodontic diagnosis and treatment for patients with unilateral cleft lip and palate in mixed dentition period.Methods: A total of 20 patients with UCLP(12 males and 8 females,the average age was 9.24±1.56 years old and cervical vertebra bone age was 9.13±1.53 years old)were selected as the UCLP group,while 20 non-CLP patients(12 males and 8 females,the average age was 9.22±1.39 years old and cervical vertebra bone age was 9.20±1.46 years old)were selected as control group.All patients were selected from the Department of Orthodontics in the Affiliated Hospital of Qingdao University.Using CBCT scanning all individuals and make 3D reconstruction used by MIMICS17.0 software.26 landmarks were identified on the three-dimensional image,such as Con?Conl?Conm?Cor?F.And to measure the distances of condylar?coronoid?anguular?middle body?chin?ramal?body?canine area height and canine area width?molar area height and molar area width and the volume of ramal and hemi-mandibular.Application of SPSS 22.0 software package for analysis of all measured data.Paired t test were used to analysis UCLP group and control group.Compared the bilateral difference of the length,width,height and volume in UCLP group and control group respectively.To analyze the difference between the UCLP group and the control group.Results:1.The symmetry of mandibular between cleft side and non-cleft side in UCLP group showed that: the measurements of coronoid length ?molar area mandibular height ?ramal volume on cleft side were larger than non-cleft side(P<0.05);Beyond that,the other comparison measurements had no statistically differences(P>0.05).2.The control group showed that there was no statistical meaning in all measurements(P>0.05).Conclusions:1.There were exist asymmetry of the mandibular in mixed dentition period with UCLP patients.The coronoid length,molar area mandibualr height and ramal volume in the cleft side were larger than the non-cleft side.The rest component structure of mandibular were essentially symmetrical in mixed dentition period with UCLP patients.2.The bilateral mandibular of non-CLP patients in mixed dentition period show good symmetry.