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Objetivo: este estudo retrospectivo avaliou a acurácia entre os resultados obtidos e o planejamento assistido por computador (PAC) em cirurgia ortognática por meio do uso de modelos de superfície tridimensionais (3D) para aplicação em algoritmo de proximidade iterativa de pontos (PIP) e produção de mapas de cores por meio de programa computacional de engenharia reversa. Material e Métodos: a partir de arquivos de tomografia computadorizada cone-beam (TCFC) de 25 pacientes submetidos à cirurgia ortognática bimaxilar, foram gerados modelos 3D do PAC e pós-operatório em formato de arquivos STL (M0 e M1, respectivamente). Os M0 e M1 foram importados para programa computacional Geomagic Wrap, sendo aplicada a função de registro por meio do algoritmo PIP para alinhamento automático e cálculos dos desvios médios (MD, MD +, MD -, SD) e quadrado médio da raiz (RMS). Os mapas de cores foram gerados para avaliar a congruência qualitativa entre M0 e M1. A partir da análise dos desvios, os RMS(s) foram definidos como ‘3D Error’ que foi utilizado como indicador de mensuração de acurácia. As características da amostra foram apresentadas por análises de estatística descritiva. Para avaliar a reprodutibilidade do método, o fluxo de trabalho foi realizado por dois avaliadores independentes. Os testes t foram utilizados para avaliar as médias de MD, MD +, MD-, SD e ‘3D Error’, segundo a hipótese de todos os valores fossem menores ou igual a - 2 mm e maiores ou igual a 2 mm. Resultados: foram encontradas altas correlações intra e inter-avaliadores, favorecendo a reprodutibilidade do fluxo de trabalho no Geomagic Wrap. Testes t rejeitaram a hipótese de que os valores MDs e ‘3D Error’ eram menores que - 2 mm e maiores que 2 mm. Conclusão: este estudo apresentou a média de ‘3D Error’ (1,27 mm) estava dentro dos padrões de sucesso clínico inferior a 2 mm. O algoritmo PIP no Geomagic Wrap forneceu um método reprodutível para relacionar as malhas de superfície dos modelos 3D, e mapas de cores foram gerados para avaliar a congruência 3D. No entanto, não há respostas para todos os parâmetros metodológicos em relação à avaliação da acurácia em cirurgia ortognática. Purpose: The aim of this retrospective study was to evaluate the accuracy between actual outcomes and virtual surgical planning (VSP) in orthognathic surgery regarding the use of three-dimensional (3D) surface models for registration using ICP algorithm and color maps by reverse engineering software. Materials and Methods: Construction of planning and postoperative 3D models in STL files format (M0 and M1, respectively) from CBCTs of 25 subjects who had been submitted to bimaxillary orthognathic surgery was performed. The M0 and M1 were sent to Geomagic Wrap Software in automatic alignment surface meshes order of M0 and M1 for registration using the ICP algorithm to calculate mean deviation (MD, MD+, MD-, SD) and root mean square (RMS). Color maps were generated to assess qualitative congruence between M0 and M1. From deviation analysis, the RMS(s) were defined as 3D Error which behaved as a measurement indicator of accuracy. The sample characteristics were shown by descriptive statistics. To evaluate the reproducibility of this method, the workflow was performed by two independent evaluators multiple times. t tests were used to assess whether all means of MD, MD+, MD-, SD and 3D Error values would be lower than - 2 mm and greater than 2 mm. Results: high intra and inter evaluators correlation were found, supporting the reproducibility of the workflow in Geomagic Wrap software. t tests proved that all MD(s) and 3D Error values were greater than - 2 mm and lower than 2 mm. Conclusion: This study showed 3D error mean (1,27 mm) within the standards of clinical success lower than 2 mm. ICP algorithm in Geomagic Wrap software provided a reproducible method of alignment between 3D models (surface meshes) and generated color maps to evaluate 3D congruence, but did not answer all methodological parameters regarding the assessment of accuracy in orthognathic surgery.

Dentofacial deformities (DFD) presenting mainly as Class III malocclusions that require orthognathic surgery as a part of definitive treatment. Class III patients can have obvious signs such as increasing the chin projection and chin throat length, nasolabial folds, reverse overjet, and lack of upper lip support. However, Class III patients can present different facial patterns depending on the angulation of occlusal plane (OP), and only bite correction does not always lead to the improvement of the facial esthetic. We described two Class III patients with different clinical features and inclination of OP and had undergone different treatment planning based on 6 clinical features: (I) facial type; (II) upper incisor display at rest; (III) dental and gingival display on smile; (IV) soft tissue support; (V) chin projection; and (VI) lower lip projection. These patients were submitted to orthognathic surgery with different treatment plannings: a clockwise rotation and counterclockwise rotation of OP according to their facial features. The clinical features and OP inclination helped to define treatment planning by clockwise and counterclockwise rotations of the maxillomandibular complex, and two patients undergone to bimaxillary orthognathic surgery showed harmonic outcomes and stables after 2 years of follow-up.