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O ameloblastoma é um tumor dentário comum, tem um comportamento localmente agressivo e é capaz de causar um extenso envolvimento das mandíbulas. A lesão freqüentemente afeta a mandíbula, especialmente a região molar e o ângulo mandibular. No exame radiográfico, geralmente tem aspecto radiolúcido e multilocular, apresentando na maioria dos casos, expansão cortical e reabsorção radicular dos dentes adjacentes. O objetivo deste artigo é relatar um caso de um paciente de 72 anos, do sexo masculino, leucodermia, com treta no serviço de Cirurgia Oral e Maxilo-facial do Hospital Pedro Ernesto. Na primeira visita, o paciente teve um aumento assintomático de volume no lado direito da face e intraoral. A tomografia computadorizada, havia imagem hipodensa, multiloculada, com perfuração da cortical, estendendo-se da porção posterior do corpo mandibular até o pescoço do côndilo e o processo coronoide à direita. Foi realizada uma biópsia incisional que mostrou o resultado do ameloblastoma multicístico. A equipe decidiu realizar a ressecção do bloco lesional com desmontagem e reconstrução com prótese TMJ personalizada. Devido à burocracia e ao tempo necessário para a aquisição desta prótese, o tratamento foi necessário para a realização de dois tempos cirúrgicos. Portanto, foi decidido ressecar a lesão e realizar a reconstrução temporária do defeito com placa de reconstrução 2,4mm, parafusos bicorticais e polimetilmetacrilato na porção do ramo mandibular e do côndilo. Aproximadamente 6 meses após a cirurgia da lesão para remover a reconstrução final foi realizada com prótese personalizada da ATM. Atualmente, o paciente está com 5 anos de pós-operatório a segunda cirurgia sem evidência de recidiva ou infecção. Apresenta-se com o contorno facial devolvido e função mastigatória satisfatória.

The aim of this study was to determine whether virtual surgical planning (VSP) is an accurate method for positioning the maxilla when compared to conventional articulator model surgery (CMS), through the superimposition of computed tomography (CT) images. This retrospective study included the records of 30 adult patients submitted to bimaxillary orthognathic surgery. Two groups were created according to the treatment planning performed: CMS and VSP. The treatment planning protocol was the same for all patients. Pre- and postoperative CT images were superimposed and the linear distances between upper jaw reference points were measured. Measurements were then compared to the treatment planning, and the difference in accuracy between CMS and VSP was determined using the t-test for independent samples. The success criterion adopted was a mean linear difference of2mm. The mean linear difference between planned and obtained movements for CMS was 1.27±1.05mm, and for VSP was 1.20±1.08mm. With CMS, 80% of overlapping reference points had a difference of2mm, while for VSP this value was 83.6%. There was no statistically significant difference between the two techniques regarding accuracy (P0.05).

Purpose To determine whether gastric aspiration performed after orthognathic surgery, in conjunction with a prophylactic protocol, could prevent postoperative nausea and vomiting (PONV). Patients and Methods Twenty-four consecutive patients treated at a single academic institution were included in this double-blinded randomized control trial and were divided into control (n = 12) and study (n = 12) groups. Patients underwent orthognathic surgery, and the same anesthetic protocol was used for the 2 groups. The only difference between groups was the performance of gastric aspiration in the study group. Patients were observed during the first postoperative day, and information concerning PONV was collected and statistically analyzed. Results The 2 groups were similar in age, gender, and medical history. There was no statistically relevant difference between the control and study groups in the overall incidence of PONV (33.3 vs 33.3%). However, there was a significant correlation between the presence of PONV after turbinectomy (P = .011) and patient dissatisfaction (P = .049). Conclusion The results of this study could not associate the performance of gastric aspiration with a decrease in the incidence of PONV after orthognathic surgery.

Background 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 iterative closest point (ICP) algorithm and generated color maps. Material and Methods Construction of planning and postoperative 3D models in STL files format (M0 and M1, respectively) from CBCT of 25 subjects who had been submitted to bimaxillary orthognathic surgery was performed. M0 and M1 were sent to Geomagic software in semi-automatic alignment surface mesh order of M0 and M1 for registration using ICP algorithm to calculate mean deviation (MD, MD+, MD-, SD) and root mean square (RMS – 3D Error). Color maps were generated to assess qualitative congruence between M0 and M1. From deviation analysis, 3D Error was defined as accuracy measurement. To assess the reproducibility, the workflow was performed by two evaluators multiple times. t-tests were used to assess whether all means of MD, MD+, MD-, SD and 3D Error values would be ≤ - 2 mm and ≥ 2 mm. Results High intra and inter evaluators correlation were found, supporting the reproducibility of the workflow. t-tests proved that all MDs and 3D Error values were > - 2 mm and < 2 mm. Conclusions 3D error mean was within the standards of clinical success lower than 2 mm. ICP algorithm provided a reproducible method of alignment between 3D models and generated color maps to evaluate 3D congruence but did not answer all methodological parameters regarding the assessment of accuracy in orthognathic surgery. Key words:Accuracy, Cone-Beam computed tomography, CAD-CAM, Orthognathic surgery, three-dimensional imaging.