Avaliação da precisão do posicionamento da maxila em cirurgia ortognática maxilomandibular comparando o planejamento cirúrgico no articulador com o planejamento cirúrgico virtual

Abstract

The success of orthognathic surgery depends not only on the technical aspects during the procedure, but also the formulation and execution of a precise surgical planning. The aim of this study was to compare the accuracy of 2 techniques for maxilomandibular orthognathic surgery planning: articulator surgical planning (ASP) and the virtual surgical planning (VSP). A retrospective study was conducted to evaluate the medical records of 30 patients submited to surgery between 2011 and 2015. Inclusion criteria were set as: 1) patients undergoing maxilomandibular orthognathic surgery; 2) availability ofpre- and postoperative computed tomography (CT); 3) availability ofsurgical planning records. Two groups were created, according to the type of surgical planning. Fifteen patients were operated after ASP (control group) and 15 after VSP (test group). The pre- and postoperative CT were superimposed and the linear distance between upper jaw reference points was measured to determine the mean linear difference between the movements planned and obtained. Data were tabulated and the accuracy between methods was determined by the t-test for independent samples. The success criterion adopted was a mean linear difference smaller than 2mm. There was no statistically significant difference between groups regarding gender (p = 0.462) and type of deformity (p = 0.425). The mean linear difference between planned and obtained movements for ASP was 1,27 mm (± 1.05 mm), and for VSP was 1,20mm (± 1,08mm). In ASP, 80% of overlapping reference points had imprecision lower than 2 mm, and 49.1% lower than 1mm. In VSP these values were 83.6% and 48.5%, respectively. There was no statistically significant difference between planning techniques regarding accuracy (p <0.05). The virtual surgical planning is a precise technique for orthognathic surgery planning. When virtual surgical planning was compared to articulator surgical planning, similar accuracy was found.