Avaliação cefalométrica do espaço orofaríngeo e do osso hióide em pacientes submetidos a cirurgia ortognática mandibular

• Autor(a) principal: Avelar, Rafael Linard
• Data de Publicação: 2013
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da PUC_RS
• Texto Completo: http://tede2.pucrs.br/tede2/handle/tede/1232
• topic: ODONTOLOGIA; CIRURGIA BUCOMAXILOFACIAL; CIRURGIA ORTOGNÁTICA; CEFALOMETRIA; CNPQ::CIENCIAS DA SAUDE::ODONTOLOGIA

OBJECTIVE: To evaluate and compare the differences and check the correlation that exists between the hyoid bone, the airways and the point B, in short and medium term preoperative and postoperative periods, after the mandibular setback and advancement surgery has taken place. MATERIAL AND METHOD: Preoperative radiography (T1), postoperative up to 3 months (T2), and postoperative after 12 months (T3) from 79 patients with facial pattern class II and III who had undergone orthognathic surgery. These radiographies were scanned, digitalized and inserted in the Dolphin Imaging 3D v. 11.0 (Dolphin Imaging Software, Canoga Park, California, EUA) to the evaluation of 6 points. All outlines were made by two evaluators and 10 % of them were repeated after two months. In order to verify the normality of the data it was used the non-parametric Kolomogorov-Smirnov test. It was considered the index of significance (p<0.05) and the GraphPad Prism statistic software was used for all analyses. RESULTS: It has been identified significant changes in all points of soft and hard tissue between the preoperative and the two postoperative periods (T2-T1) and a significant level of accommodation of tissues (T3-T1) on the hyoid bone and airways. In T3-T1 (accommodation movement of the hyoid bone) it is observed a gradual return of the hyoid bone after the realization of the orthognathic surgery, mainly in movements above 3mm (p<0.05). During the 12 months of monitoring, it was observed a posterior movement of the hyoid bone in setback jaw surgery and anterior movement in forward jaw surgery (p<0.05), with a consequent return to the preoperative position 12 months after the surgery. Regarding the airways, the medium and minimum setback did not show significant variation in long term period (p>0.05), what happened differently of the lower airway, in which there was a shortening of the airways after one year of monitoring (p<0.05). In the foward jaw movement there was a widening of airways, showing a return close to the initial one, 12 months after the surgery (p<0.05). CONCLUSION: It has been observed in this study that the hyoid bone tends to return to the original position, mainly when it is present a setback above 3 mm and greater ones. The same holds true regarding the airways, in which it is observed a shortening of the airways in greater mandibular setbacks; and widening of the airways in greater mandibular forward movement, with a gradual return after 12 months. The Pogonion point and the B point showed a far posterior positioning, presenting a greater recidivism when the mandibular movements were bigger. The opposite happened in the mandibular forward movement cases.