Maxillomandibular Characteristics Related To Mandibular Asymmetry In Brazilian Adolescents With Different Sagittal Skeletal Patterns

Objective: evaluate maxillomandibular characteristics associated to mandibular asymmetries in brazilian adolescents who present different sagittal skeletal patterns using cone beam computed tomography (CBCT). Methods: tomographic images of 210 patients were selected and divided into three groups of 70 individuals each (Class I; Class II; and Class III). The groups were subdivided into three categories according to the degree of the lateral chin (gnathion) deviation 1) relative symmetry; 2) moderate asymmetry; and 3) severe asymmetry. Three planes of reference were established in the CBCT images and several measures were taken to compare bilateral skeletal differences within asymmetry degrees for the different sagittal skeletal patterns. Results: In the transverse plane, Gn-MSP and Go-MSP showed statistical differences, different from J-PSM (P>0,05). In the sagittal plane, Go-Coronal (dif) showed a significant difference in the severe asymmetry in Class III individuals. However, GoGn (dif) presented significant difference in the asymmetry for all the sagittal skeletal patterns. Evaluations on the vertical plane showed that CoGo (dif) was significantly different in Class I and II individuals with severe asymmetry, and in Class III individuals, for all mandibular asymmetries. When comparing Class I, II and III individuals regarding the different asymmetry intensities, it became evident that one sagittal plane measure, Go-Coronal (dif), and one vertical measure, J-Camper (dif) were significantly different in Class II and III sagittal skeletal patterns, respectively, in individuals with severe asymmetry. Conclusion: lateral chin deviation was not the only skeletal alteration found in patients with asymmetry; there was variation of the bilateral differences among the degrees of asymmetry and sagittal skeletal patterns; bilateral differences of the maxilla position followed the mandibular ones only in the vertical direction and in Class II and III patients. Keywords : Facial Asymmetry, Cone-Beam Computed Tomography, Adolescent