Three dimensional evaluatr of dental and skeletal asymmetry of patient with Class I, Class II and Class III malocclusion

The aim of this study is to three dimensional evaluate of dental and skeletal asymmetry of patients with Class I, Class II and Class III malocclusion. The material of this study is consisted of CBCT (Cone beam computer tomography) images of 20 Class I (mean age: 24,9 ± 3,5), 20 Class II (mean age: 20,9 ± 3,7) and 20 Class III (mean age: 21,2 ± 2,3) patients. The data obtained from the CBCT images were transferred to the Dolphin 3D software. A total of 97 parameters (89 linear and 8 angular) were studied. SPSS (Statistical Package for Social Sciences) for Windows 15.0 software were used for statistical analysis. One-way ANOVA test was used to evaluate the between group differences. When any significant differences were observed between groups, Tukey HSD test was used to identify the group which is the cause of the differences. Paired-t test was used to compare the right and left parameters within groups. According to the statistically data obtained from the study, not significant asymmetry were observed between the right and left dental parameters. According to the intergroup evaluation of the right anterior-posterior molar difference and overjet parameters, differences which correspond with the characteristic features of groups were observed (p?0.01). Significant asymmetry was observed between the right and left ramus, corpus length and mandibular plane angle parameters of Class I and Class III groups (p?0.01). Significant differences were observed between right and left mandibular, ramus length and gonial angle parameters of Class II group (p?0.01). Significant differences were observed from the comparison of most of the maxillary and the mandibular asymmetry related parameters among Class I, II and III groups (p?0.01). According to the condyler asymmetry evaluation, significant differences were observed between the right and left 3D anteroposterior length of the condyler head in Class I group and 3D upper condyler space in Class II group. However, no significant asymmetry was observed in Class III group. 3D anteroposterior length of the condyler head in the right and left side of Class I group was found significantly larger than Class II and III groups. Angle between the plane intersection by the right and the left mediolateral points and coronal plane was found smaller in Class II group than Class III group. The distance of the right and left medial, lateral and posterior point of the condyler head to the sagittal plane was found greater in Class I group than the other groups. According to the evaluation of orthogonal asymmetry to the coronal plane, no significant differences were found between the right and left parameters in Class I, II and III groups. Orthogonal asymmetry to the coronal plane to the right and left by the comparison between the groups in the distance of the lowest point of the articular eminence, the back, front and the top point of the condyle head to the coronal plane class I and class III were found to be more than class III group. The distance from the coronal plane to the pogonion point, class III group was found to be longer than class I and class II group. According to the evaluation of orthogonal asymmetry to the axial plane, class I-II and III groups were symmetrical in terms of left and right parameters. The distance of the right and left the front, the back point of the condyle head and the bottom point of the articular eminence, of the axial plane between the groups is determined as not symmetrical. As a result, in group dental asymmetry was not observed in all three groups. With skeletal, condylar evaloation, orthogonal asymmetry to the coronal plane, and less commonly orthogonal asymmetry to the axial plane, there were determined some differences. Comparasions between groups, differences were found due to its own characteristic feature. Key Words: Computed tomography, 3D cephalometry, asymmetry, ClassI, ClassII, Class III malocclusion.