Avaliação da morfologia craniofaciall de indivíduos com deformidades dentofaciais de classe III por meio de tomografias computadorizadas de feixe cônico / Evaluation of the craniofacial morphology of subjects with dentofacial Class III deformities using cone beam computed tomography

AUTOR(ES)
DATA DE PUBLICAÇÃO

2009

RESUMO

Class III dentofacial deformity is associated with important functional, psychologic and aesthetics changes. The objective of this study was to evaluate the craniofacial morphology of adults, with Class III dentofacial deformity comparing them with a group of subjects with harmonious faces for diagnosis and prognosis in orthodontic and surgical cases. This study evaluated 50 subjects that were submitted to the cone beam computed tomography (i-Cat®/ Cone beam 3-D Dental Imaging System, Imaging Sciences International, Hatfield, USA) with the purpose of diagnosis. The sample was divided in two groups, one with 25 subjects with harmonious faces and excellent occlusion and another with 25 subjects with Class III malocclusion, that are in treatment in the orthodontic clinic for orthognathic surgery in the Faculty of Dentistry of University of São Paulo. After the digital archives were obtained, the 3D reconstruction of images were performed with the softwares Dolphin 3D® (Dolphin Imaging and Management Solutions, Chatsworth, CA EUA) and Maxilim® (Medicim- Medical Image Computing, Mechelen-Bélgica). After demarcation of the reference points, linear, angular and proportional measurements were made and represented in statistical analysis, by mean and standard deviation. To determine the error of method, intraclass correlations were calculated, and Dahlbergs formula was used. To compare both groups the Variance Analyses was applied (ANOVA) with two factors, representing occlusion and gender. When statistical significant differences were observed, Tukeys multiple comparison was performed to evaluate in which gender the variance happened. The level of significance adopted was 5%. The error of method showed high reproducibility for intra-operator evaluation in Dolphin 3D® and Maxilim® softwares. Cephalometric 3D evaluation of the groups, showed significant differences (p<0,05), and the group with Class III dentofacial deformity showed changes in the relationship of height and width, associated with an augmented height of the lower face; clock-wise rotation of the mandible related to an increase of the inclination of the mandible body and ramus and a greater anterior facial height in relation to the posterior facial height; decrease in the size and angulation of the cranial base; compensation in height of dentoalveolar maxilla; predominant mandibular size in anterior-posterior configuration of the facial skull and vertical dentoalveolar compensations that reduced to alveolar level the structural skeletal unbalance.

ASSUNTO(S)

ortodontia orthodontics tomografia computadorizada de feixe cônico cone beam computed tomography cephalometry cefalometria

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