A New Software Suite in Orthognathic Surgery : Patient Specific Modeling, Simulation and Navigation.

Orthognathic surgery belongs to the scope of maxillofacial surgery. It treats dentofacial deformities consisting in discrepancy between the facial bones (upper and lower jaws). Such impairment affects chewing, talking, and breathing and can ultimately result in the loss of teeth. Orthognathic surgery restores facial harmony and dental occlusion through bone cutting, repositioning, and fixation. However, in routine practice, we face the limitations of conventional tools and the lack of intraoperative assistance. These limitations occur at every step of the surgical workflow: preoperative planning, simulation, and intraoperative navigation. The aim of this research was to provide novel tools to improve simulation and navigation. We first developed a semiautomated segmentation pipeline allowing accurate and time-efficient patient-specific 3D modeling from computed tomography scans mandatory to achieve surgical planning. This step allowed an improvement of processing time by a factor of 6 compared with interactive segmentation, with a 1.5-mm distance error. Next, we developed a software to simulate the postoperative outcome on facial soft tissues. Volume meshes were processed from segmented DICOM images, and the Bullet open source mechanical engine was used together with a mass-spring model to reach a postoperative simulation accuracy <1 mm. Our toolset was completed by the development of a real-time navigation system using minimally invasive electromagnetic sensors. This navigation system featured a novel user-friendly interface based on augmented virtuality that improved surgical accuracy and operative time especially for trainee surgeons, therefore demonstrating its educational benefits. The resulting software suite could enhance operative accuracy and surgeon education for improved patient care.

3D printing in orthognathic surgery - A literature review.

With the recent advances in three-dimensional (3D) imaging, computer-assisted surgical planning and simulation are now regularly used for analysis of craniofacial structures and improved prediction of surgical outcomes in orthognathic surgery. A variety of patient-specific surgical guides and devices have been designed and manufactured using 3D printing technology, which rapidly gained widespread popularity to improve the outcomes. The article presents an overview of 3D printing technology for state-of-the-art application in orthognathic surgery and discusses the impacts on treatment feasibility and patient outcome. The current available literature regarding the use of 3D printing methods in orthognathic surgery including 3D computer-aided design/computer-aided manufacturing, rapid prototyping, additive manufacturing, 3D printing, 3D printed models, surgical occlusal splints, custom-made guides, templates and fixation plates is reviewed. A Medline, PubMed, ProQuest and ScienceDirect search was performed to find relevant articles over the past 10 years. A total of 318 articles were found, out of which 69 were publications addressing the topic of this study. An additional 9 hand-searched articles were added. From the review, we can conclude that the use of 3D printing methods in orthognathic surgery provide the benefit of optimal functional and aesthetic results, patient satisfaction, and precise translation of the treatment plan.

Evolución hacia la era digital de la cirugía ortognática: experiencia en un centro universitario / Evolution towards the digital era of orthognatic surgery: experience in a university center

Resumen Introducción: La incorporación de tecnologías en la práctica quirúrgica, ha cambiado la forma de enfrentar el proceso quirúrgico. Objetivo: Describir la experiencia de los últimos 9 años, en cirugía ortognática, con la incorporación de la cefalometría 3D. Materiales y Método: Se realizó una revisión retrospectiva de pacientes operados de cirugía ortognática durante el período enero de 2011 a agosto de 2018. Se registraron datos demográficos, quirúrgicos, tipo de planificación quirúrgica, complicaciones y resultados a largo plazo. Resultados: 21 pacientes requirieron cirugías ortognáticas. Se realizaron 16 cirugías bimaxilares (76%), 3 cirugías de avance maxilar superior (14%) y 2 cirugías de osteotomía sagital de rama (10%). Las principales etiologías fueron: 67% maloclusión clase III (n = 14), 28% maloclusión clase II (n = 6) y 5% desviación mandibular (n = 1). La planificación prequirúrgica virtual fue utilizada en 11 pacientes (52%). La tasa de complicaciones Clavien-Dindo > III fue 4,8% (n = 1). Conclusiones: En nuestra experiencia, las técnicas de cirugía ortognática son seguras. Las complicaciones de la serie fueron escasas y bien toleradas por los pacientes. Durante los últimos años y, de acuerdo a los avances tecnológicos, la incorporación de la planificación quirúrgica virtual 3D favoreció el desarrollo de la cirugía ortognática en nuestro centro.

Introduction: Technological advances have been incorporated into cranio-maxillo-facial surgery changing the clinical practice of surgeons. Aim: The aim of this article is to describe our experience in orthognatic surgery in the last 9-years, with the incorporation of 3D cephalometry. Materials and Method: A retrospective chart review was performed from January 2011 to August 2018 on patients undergoing Orthognatic Surgery. Demographic and surgical data, type of surgical planning, complications and long-term results were recorded. Results: A total of 21 patients underwent orthognatic surgery. Average age was 28 years (DE 8.1), 11 men (52.3%) and 10 women (47.61%). The principal surgeries performed were: 16 (76%) bimaxillary, 3 maxillary advancement surgery 3 (14%) and bilateral sagital split osteotomy 2 (10%). Ethiologies were: 14 patients (this 67%) with malocclusion class III, 6 patients (28%) with malocussion class II, and 1 patient (5%) with mandibular deviation. Virtual 3D presurgical planning was used in 11 patients (52%). The total of complications Clavien-Dindo > III was 4.8% (n = 1). None patient required reoperation. Satisfaction rate with the procedure was high. Conclusions: Based on our experience, orthognatic surgery techniques are safe. The complication rate was lower and well tolerated by patients. The introduction of virtual planning provided a better scenario to develop maxillo-facial surgery.

Latest trends in craniomaxillofacial surgical instrumentation.

PURPOSE OF REVIEW: To review the past year's literature regarding recent innovations in surgical instrumentation for craniomaxillofacial surgery. RECENT FINDINGS: Current advances in surgical instrumentation have led to many improvements in the field, allowing greater visualization and precision both before and during procedures. One of the common goals is to achieve excellent outcomes with minimal complications, while at the same time minimizing invasiveness of surgery. Highlighted innovations include greater capacities for acquisition of data, leading to improved imaging modalities and expansion of computer-assisted surgical techniques; continued developments in biomaterials used in various reconstructions; and novel uses of bone cutting and bone fixation instrumentation. SUMMARY: Technology in the field of craniomaxillofacial surgery is developing rapidly, leading to novel instrumentation being utilized across a broad spectrum of areas. Published data have been encouraging to date, indicating an ever increasing adaptation of these innovations in clinical practice. Future efforts need to focus on cost-benefit analysis and constructing larger-scale studies to better understand effectiveness and patient outcomes.

Distracción ósea y cirugía ortognática en paciente previamente radiado / Bone distraction and orthognathic surgery on previously irradiated patients

Introducción. Presentamos a un paciente que recibió tratamiento radioterápico en la infancia por un retinoblastoma. Como principal secuela presenta una severa hipoplasia ósea hemifacial, alteración de la dentición y atrofia muscular. Se realiza cirugía correctora facial mediante distracción ósea, cirugía ortognática y lipoescultura facial con un resultado estético y funcional excelente y estable hasta el momento actual. Caso clínico. Varón de 15 años con hipoplasia témporo-parieto-frontal, orbitaria izquierda y del tercio medio facial con un plano oclusal inclinado, resalte de más de 25 mm y múltiples piezas dentales con microdoncia y rizólisis. A los 19 años, inicia ortodoncia prequirúrgica y la colocación de distractores tipo Zurich en el maxilar superior. Se consigue un avance maxilar de 25 mm. A los 21 años se realiza cirugía ortognática bimaxilar y lipoescultura facial. Resultados. Paciente con mejoría de la simetría facial, oclusión en clase i con plano oclusal alineado. Resultados estables hasta el momento actual, con 23 años. Continúa con ortodoncia posquirúrgica y rehabilitación dental. Discusión. Se obtuvo una buena consolidación, con una calidad ósea excelente desde el punto de vista clínico y radiológico, sin presentar complicaciones. Otro beneficio de la distracción es el efecto expansor de los tejidos blandos. La distracción ósea y la cirugía ortognática bimaxilar son métodos prometedores en la reconstrucción del territorio maxilofacial en pacientes radiados con una deformidad dentofacial como secuela oncológica (AU)

Introduction. We report the case of a patient who received radiotherapy in childhood for retinoblastoma. The main sequelae of this was, severe bone hemifacial hypoplasia, abnormal dentition, and muscle atrophy. Corrective facial surgery was performed through bone distraction, orthognathic surgery, and facial liposuction, with excellent and stable aesthetic and functional results to date. Case. report A 15 year-old patient with left temporo-parieto-frontal and orbital hypoplasia and midface hypoplasia with an inclined occlusal plane, overjet more than 25 mm and multiple teeth with microdontia and rhizolysis. At 19 years old, presurgical orthodontics and placement of Zurich type maxillar distractors were started. An advancing of 25 mm was achieved. At 21years old, bimaxillary orthognathic surgery and facial liposuction was performed. Results. Patient improvement in facial symmetry, occlusion type i of Angle classification with inclined occlusal plane. Stable results to date on a 23 year-old patient. Continues with post-surgical orthodontic and dental rehabilitation. Discussion. Good bone consolidation was obtained, with excellent bone quality from a clinical and radiological point of view, with no complications. Another benefit is the distraction expanding effect of the soft tissue. Osteogenesis distraction and bimaxillary orthognathic surgery are promising methods in maxillofacial reconstruction on irradiated patients with dentofacial deformity as oncology sequelae (AU)

Planificación tridimensional y utilización de férulas Computer Aided Design/Computed Aided Manufacturing en cirugía ortognática / 3D planning and use of Computer Aided Design/Computed Aided Manufacturing surgical splints in orthognathic surgery

El presente trabajo se centra en explicar las ventajas que aporta la planificación tridimensional (3D) y la confección de férulas quirúrgicas Computer Aided Design/Computed Aided Manufacturing (CAD/CAM) en cirugía ortognática. La digitalización del entorno laboral es una realidad imparable en nuestra sociedad y, en nuestra especialidad, nos proporciona ventajas desde un punto de vista logístico, de precisión diagnóstica y en la confección de férulas quirúrgicas. Las tradicionales férulas quirúrgicas siguen un método de fabricación casi artesanal sometido a errores sistemáticos que se van acumulando a lo largo del proceso. Las férulas CAD/CAM se crean directamente a partir de imágenes que obtenemos de la tomografía computarizada o de la tomografía de haz cónico con lo que acortamos, digitalizamos y estandarizamos el proceso de confección disminuyendo la posibilidad de cometer errores derivados de la confección manual. Las imágenes 3D sobre las que podemos trabajar nos aportan ventajas respecto a la visualización bidimensional (2D) ya que no hay una pérdida de información ni una superposición de estructuras anatómicas. En 3D podemos ver con mayor detalle puntos de referencia difíciles de visualizar en 2D y son imágenes idóneas para el estudio de asimetrías en el plano frontal (AU)

The aim of this work is to present the advantages of 3D planning and CAD/CAM (Computer Aided Design/Computed Aided Manufacturing) surgical splints in orthognathic surgery. Digitalization of the working environment is an unstoppable reality in our society and, in our specialty it gives us advantages from a logistics, accuracy and diagnostic point of view, as well as in the manufacture process of surgical splints. The conventional surgical splints have an artisanal manufacturing process subjective to systematic errors. CAD/CAM surgical splints are built from computed tomography or cone beam computed tomography, which makes manufacturing process shorter, digitalized and standardized, thus decreasing the errors of the hand made manufacture. The 3D images that we can work with, give us advantages compared to two-dimensional (2D) visualization because there is no loss of information or overlapping anatomical structures. More detailed points of references can be seen in 3 D images, which are very difficult to see in two-dimensional images, and are ideal images for the study of frontal plane asymmetry (AU)

Planificación clásica en cirugía ortognática / Classic planning in orthognatic surgery

La cirugía ortognática es una de las cirugías electivas realizadas más a menudo en cirugía maxilofacial. Su planificación debe ser minuciosa, asegurando un grado de precisión tal que el margen de error sea de menos de 1 mm. El método clásico de planificar una cirugía ortognática se basaba en una cefalometría realizada a partir de una telerradiografía de perfil. A partir de aquí se trazaba una STO (Surgical Treatment Objectives) que permitía imaginar y medir en la dirección sagital los cambios quirúgicos. Concomitantemente, la cirugía de modelos corroboraba los cambios previstos con la STO. El desarrollo de las tomografías de haz de cono (CBCT) y su posterior incorporación a nuestras respectivas clínicas ha facilitado el paso de una planificación 2D basada en radiografías convencionales de perfil y ortopantomografía, a una planificación 3D basada en CBCT. Existe más de un enfoque correcto en la planificación y tratamiento de pacientes de cirugía ortognática. Cada paciente debe ser planificado y tratado de forma personalizada, según una serie de criterios. Existen pruebas adyuvantes como el escáner de haz de cono, planificación guiada por el escáner, férulas quirúrgicas CAD-CAM, modelos 3D craneales de resina o incluso cirugía con navegación asistida por robot que pueden ser útiles para mejorar los resultados quirúrgicos y disminuir el riesgo quirúrgico. Esto puede ser especialmente importante en deformidades severas, con un crecimiento anómalo y requiriendo maniobras quirúrgicas especialmente complicadas. Además, la cirugía endoscópica y la cirugía asistida por robot para navegar, están en rápido desarrollo y pueden en casos seleccionados especialmente complejos estar justificados. El objetivo de este artículo es discernir cuando son necesarias tales herramientas en cirugía ortognática (AU)

Orthognathic surgery is one of the elective surgery most often performed in maxillofacial surgery. Their planning must be thorough, ensuring a degree of precision such that the margin of error is less than 1 mm. The classical method for planning orthognathic surgery was based on a cephalometric made from a teleradiography profile. From here outlines a STO (Surgical Treatment Objectives) allowing imagine and measured in the sagittal direction surgically changes. Concomitantly, the model surgery corroborated the expected changes with the STO. The development of cone-beam CT (CBCT) and its subsequent incorporation into our respective clinics has facilitated the transition from a 2D plan based on conventional radiographs and panoramic radiograph profile, a CBCT-based 3D planning. More than one correct approach and treatment planning for orthognathic surgery patients. Each patient should be planned and treated in a personalized way, according to a set of criteria. Evidence exists adjuvants such as cone beam scanner, scanner guided planning, splints, surgical CAD-CAM, 3D models resin or cranial surgery with robot-assisted navigation can be used to improve surgical outcomes and reduce the surgical risk. This may be especially important in severe deformities with abnormal growth and requiring particularly complex surgical procedures. In addition, endoscopic surgery and robotic-assisted surgery for navigation, are rapidly developing in selected cases may be justified particularly complex. The aim of this paper is to discern when such tools are necessary in orthognathic surgery (AU)

Avaliação da previsibilidade do planejamento virtual da cirurgia ortognática / Evaluation of predictability of orthognathic surgery performed according to the virtual planning

O objetivo dos autores foi avaliar a previsibilidade da cirurgia ortognática realizada segundo o planejamento virtual tridimensional. Para o presente estudo, foram selecionadas 28 tomografias computadorizadas de feixe cônico (14 pré cirúrgicas e 14 pós cirúrgicas) referentes à 14 pacientes que se submeteram ao tratamento ortodôntico com cirurgia ortognática realizada a partir do planejamento virtual. Após orientação das imagens, 3 pontos dentários foram marcados em cada arcada nas imagens tomográficas dos tempos pré e pós-cirúrgicos, assim como no planejamento. Os valores que representam a localização no espaço de cada um dos pontos foram tabelados. Foi realizado o cálculo do desvio quadrático médio entre dados do planejamento e da movimentação real e, utilizando o Teste T pareado ou Wilcoxon, a depender a distribuição dos dados, foram comparados os dados dos tempos pré e pós-cirúrgicos e o valor real de deslocamento com o planejado. O desvio quadrático médio foi acima de 2mm no eixo anteroposterior para os dentes 21 e 16 nos casos em que era planejado avanço mandibular. Analisando-se os tempos pré e pós cirúrgicos, houve diferença estatisticamente significativa no eixo anteroposterior para os pontos demarcados em dentes superiores. Em relação à comparação entre o deslocamento real obtido e o que foi planejado, não houve diferença estatisticamente significativa. O planejamento virtual tridimensional mostrou-se como ferramenta válida para planejamento e realização de cirurgias ortognáticas, trazendo resultados dentro do limite do que consideramos clinicamente aceitável. (AU)

The objective of the authors was to evaluate the predictability of orthognathic surgery performed according to the virtual three-dimensional planning. For the present study, 28 concomitant CT scans (14 preoperative and 14 postoperative) were selected for 14 patients who underwent orthodontic treatment with orthognathic surgery performed through virtual planning. After orientation of the images, 3 dental landmarks were delimited in each dental arch in the tomographic images of pre and post-surgical times, as well as in the planning. The values representing the location in the space of each of the points were tabulated. The mean square deviation between planned and actual movement data was calculated and, using the paired TTest or Wilcoxon, the pre and post-surgical data were compared, as well as the actual displacement value to the planned one. The mean square deviation was above 2mm in the anteroposterior axis for teeth 21 and 16 in cases where mandibular advancement was planned. Analyzing the pre and post surgical times, there was a statistically significant difference in the anteroposterior axis for maxillary teeth. Regarding the comparison between the actual displacement obtained and what was planned, there was no statistically significant difference. The threedimensional virtual planning proved to be a valid tool for planning and performing orthognathic surgeries, bringing results within the limits of what we consider to be clinically acceptable. (AU)

Ortodontia Lingual: o preparo para cirurgia ortognática / Lingual Orthodontics: preparation for orthognathic surgery

A Técnica Lingual é uma opção mais atraente para os pacientes adultos que necessitam de tratamento ortodôntico. Atualmente, a demanda de pacientes com indicação de cirurgia ortognática, que fazem questão do uso de aparelhos linguais, tem levado os ortodontistas a desenvolver opções para essa situação, até então incomum, devido à ausência de bráquetes na superfície vestibular dos dentes utilizados como apoio para os elásticos intermaxilares necessários nos procedimentos cirúrgicos. Este artigo propõe-se a apresentar quatro formas de preparo ortodôntico para cirurgia ortognática que permitem a utilização de elásticos intermaxilares apoiados por vestibular mesmo com a utilização de bráquetes linguais.

The lingual technique is a more attractive option for adult patients in need of orthodontic treatment. Currently, the demand of patients requiring orthognathic surgery who insist on wearing lingual appliance has led orthodontists to create options to resolve the until then uncommon situation due to the absence of brackets on the labial and buccal surfaces of the teeth used as anchor for intermaxillary elastics necessary in surgical cases. This paper aims at presenting four different forms of orthodontic preparation for orthognathic surgery that allow the use of intermaxillary elastics attached to the labial and buccal surfaces of the teeth, even with the use of lingual brackets.

Preparo ortodôntico em cirurgia ortognática / Orthodontic preparation in orthognathic surgery: clinical case report

A deformidade dentofacial é um problema severo de má-oclusão, que pode provocar alterações na estética facial, problemas mastigatórios, desordens temporomandibulares, alterações na respiração e na fala. O tratamento desta má-oclusão, na idade adulta, envolve a correção ortodôntica combinada com a cirurgia ortognática. O preparo ortodôntico-cirúrgico merece considerável atenção em relação às descompensações dentárias, com a finalidade de permitir correto posicionamento das bases ósseas durante a cirurgia ortognática. O objetivo deste trabalho foi discorrer sobre os pontos importantes do preparo ortodôntico-cirúrgico, a fim de permitir uma adequada correção estética e funcional da oclusão.

Dentofacial deformity is a severe problem of malocclusion that may cause alterations in facial esthetics, masticatory problems, temporomandibular disorders, alteration in respiration and speech. Treatment of this malocclusion at an adult age involves orthodontic correction combined with orthognathic surgery. Orthodontic-surgery preparation deserves considerable attention as regards dental decompensations, with the purpose of allowing correct positioning of the bony bases during orthognathic surgery. The aim of this study is to discourse about important points of orthodontic-surgery preparation, in order to allow adequate static and functional correction of the malocclusion.

Análisis de la ubicación vertical y profundización del pin frontal en cirugía ortognática / Analysis of the vertical position and depth of the external pin in orthognatic surgery

Introducción. Al reposicionar verticalmente el maxilar es necesario contar con un aditamento externo llamado pin, que permite realizar las mediciones durante la cirugía, y así movilizar el maxilar según lo planificado. Los sitios más utilizados para introducir el pin son el nasion y glabela, pero ¿cuál de estos es el ideal?, siendo ideal aquella zona que de mayor retención, estabilidad y menor posibilidad de complicaciones. Objetivo. Analizar desde un punto de vista anatómico el mejor sitio para la introducción del pin, y proponer una ubicación única universal tanto en sentido vertical como sagital, utilizable para todo tipo de paciente. Material y método. Se realizó un estudio exploratorio, seleccionando al azar 99 pacientes de edad entre los 21 a los 27 años, todos estudiantes de odontología de la Universidad de los Andes Santiago de Chile, a los cuales se les efectuó una radiografía de perfil, midiendo el grosor de tejido óseo y blando a nivel del nasion y glabela. Se dividió a los pacientes por sexo y biotipo con el fin de evaluar similitudes en las mediciones de grosores. Resultados. Se encontró gran diferencia de los grosores en los distintos grupos tanto en nasion como en glabela. Se determinó un mayor grosor de tejido óseo y blando a nivel de nasion, resultando un grosor mínimo total de 13,83mm en nasion y 6,37mm en glabela. Conclusión. Debido al gran margen de grosores es muy difícil determinar un valor único estándar en la introducción del pin, considerando como sitio de elección el nasion (AU)

Introduction. To vertically reposition the maxilla it is necessary to have an attachment called the external pin, which allows for measurements to be taken during surgery. The sites most often used to insert the pin are the nasion and glabella, but the question remains as to which of these two sites is the optimum as regards increased retention, stability, and less chance of intraoperative and postoperative complications. Objectives. The objective of this study is to analyze the best place for the introduction of the pin from an anatomical point of view, and propose a universal unique location in both vertical and sagittal directions that will be usable for all types of patients. Materials and methods. We performed an exploratory study, randomly selecting 99 patients aged 21 to 27 years, all of whom were dental students at the University of the Andes, Santiago de Chile. They all had a lateral radiograph, measuring the bone and soft tissue thickness at nasion and glabella level. The patients were grouped by sex and biotype to assess similarities in the thickness measurements. Results. There were no significant differences in the thicknesses of the nasion and glabella in the various groups. Greater bone and soft tissue thickness was found at nasion level (a total minimum thickness of 13.83mm) than in the glabella, 6.37mm. Conclusion. Due to the wide range of thicknesses it was impossible to determine a single value standard for the introduction of the pin, with the nasion being considered the site of choice (AU)

Osteotomía distal mandibular y fractura en tallo verde / No disponible

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