Guías y miniplacas personalizadas: un protocolo guiado para cirugía ortognática / Customised guides and mini-plates: a guided-protocol for orthognathic surgery

Introducción. Los avances tecnológicos en planificación e impresión 3D permiten sinterizar productos sanitarios personalizados mediante un flujo de trabajo completamente digital. El objetivo de este trabajo es presentar y evaluar un nuevo sistema posicionador para cirugía ortognática (SPO), basado en el uso de una guía hueso-soportada y una miniplaca personalizada, que permite posicionar el fragmento maxilar sin la necesidad de una férula oclusal intermaxilar. Material y métodos. Se trata de un estudio prospectivo observacional sobre 10 casos de cirugía bimaxilar en los que se ha seguido un protocolo de planificación inversa. Tanto la guía como la miniplaca personalizada fueron diseñadas con tecnología computer aided-desing/manufacturing (CAD-CAM) y fabricadas por sinterizado láser de polvo de titanio puro comercial. Para analizar la precisión obtenida, se realizó un estudio comparativo superponiendo la planificación con una tomografía computarizada realizada un mes posterior a la cirugía. Resultados. El SPO se pudo aplicar con éxito en todos los casos sin observarse fenómenos de intolerancia al material. Permitió simplificar notablemente el procedimiento y reducir los tiempos quirúrgicos, al evitar la fijación intermaxilar, el moldeado de la miniplaca y la necesidad de realizar mediciones intraoperatorias. En el estudio postoperatorio se obtuvo una precisión media del 68,1% ±1mm. Conclusiones. Los sistemas de posicionamiento para cirugía ortognática que incluyan sistemas personalizados de osteosíntesis pueden ser una opción de futuro que permita incrementar la precisión y la seguridad del procedimiento, así como reducir los tiempos quirúrgicos (AU)

Introduction. Technological advances in preoperative planning and 3D printing allow custom-made biomedical devices to be synthesised using a completely digital workflow. The aim of this paper is to present and critically evaluate a new Orthognathic Positioning System (OPS) for Orthognathic Surgery. The OPS used bone-supported guides and a custom mini-plate to allow maxillary fragment positioning and fixation without the need for an inter-maxillary occlusal splint. Materials and methods. A prospective observational study was conducted on 10 cases of bimaxillary surgery using an inverse planning protocol. The guide and the custom-made mini-plate were designed using CAD-CAM software and synthesised by laser from commercially pure titanium powder. Accuracy was evaluated by overlap comparison of the virtual planning and 1-month postoperative CT scan. Operation times, complications, and overall safety profile were analysed. Results. The OPS was successfully applied to all cases, and was well tolerated. Operation times were reduced by avoiding inter-maxillary fixation, mini-plate bending, and obviating the need for intra-operative measurements. A mean postoperative accuracy of 1mm was obtained in 68.1% of cases. Conclusions. The positioning systems for orthognathic surgery that involve custom made systems of osteosynthesis, can be a future option that could increase accuracy and the safety of the procedure, as well as the surgical times. We believe this novel technology is a step forward in optimising and improving the delivery of orthognathic surgery care (AU)

Custom-Machined Miniplates and Bone-Supported Guides for Orthognathic Surgery: A New Surgical Procedure.

PURPOSE: Several surgical strategies exist to improve accuracy in orthognathic surgery, but ideal planning and treatment have yet to be described. The purpose of this study was to present and assess the accuracy of a virtual orthognathic positioning system (OPS), based on the use of bone-supported guides for placement of custom, highly rigid, machined titanium miniplates produced using computer-aided design and computer-aided manufacturing technology. MATERIALS AND METHODS: An institutional review board-approved prospective observational study was designed to evaluate our early experience with the OPS. The inclusion criteria were as follows: adult patients who were classified as skeletal Class II or III patients and as candidates for orthognathic surgery or who were candidates for maxillomandibular advancement as a treatment for obstructive sleep apnea. Reverse planning with computed tomography and modeling software was performed. Our OPS was designed to avoid the use of intermaxillary fixation and occlusal splints. The minimum follow-up period was 1 year. RESULTS: Six patients were enrolled in the study. The custom OPS miniplates fit perfectly with the anterior buttress of the maxilla and the mandible body surface intraoperatively. To evaluate accuracy, the postoperative 3-dimensional reconstructed computed tomography image and the presurgical plan were compared. In the maxillary fragments that underwent less than 6 mm of advancement, the OPS enabled an SD of 0.14 mm (92% within 1 mm) at the upper maxilla and 0.34 mm (86% within 1 mm) at the mandible. In the case of great advancements of more than 10 mm, the SD was 1.33 mm (66% within 1 mm) at the upper maxilla and 0.67 mm (73% within 1 mm) at the mandibular level. CONCLUSIONS: Our novel OPS was safe and well tolerated, providing positional control with considerable surgical accuracy. The OPS simplified surgery by being independent of support from the opposite maxilla and obviating the need for classic intermaxillary occlusal splints.