Cephalometric for Orthognathic Surgery (COGS) Analysis for Saudi Population

ABSTRACT Objective: To establish the cephalometric (Ceph.) norm by Ceph. for orthognathic surgery (COGS) analysis for Saudi population. Material and Methods: 500 adult Saudi samples (250 males and 250 females) with the age range of 18-30 years old were selected for this study. The selections of samples were based on a normal occlusal relationship, no history of facial trauma and no previous orthodontic treatment. Lateral Ceph. radiographs were tracing by CASSOS software and analyzed by SPSS software according to COGS analysis. Results: Significant differences were showed between the Saudi males and females on most of the Ceph. parameters. The Saudi males had a convex facial profile with chin prominent and more bimaxillary protrusion, upper and lower lip protrusion than the Saudi females. Conclusion: This study evaluated the craniofacial morphological difference between the male and the female population in Saudi Arabia by using COGS analysis. The finding of this study will help for better diagnosis of orthodontic and orthognathic surgical treatment planning and identify the morphological facial characteristics of Saudi patients.

Prevention of Nasal Ala Pressure Injuries With Use of Hydroactive Dressings in Patients With Nasotracheal Intubation of Orthognathic Surgery: A Randomized Controlled Trial.

PURPOSE: To compare a hydroactive dressing to an adhesive tape standard of care in the prevention of nasal ala pressure injuries associated with nasotracheal intubation during orthognathic surgery. DESIGN: Randomized controlled trial. SUBJECTS AND SETTING: The study took place in a tertiary hospital of stomatology in China. Patients undergoing general anesthesia with nasotracheal intubation during orthognathic surgical procedures were invited to participate. METHODS: Participants were divided into 2 groups: in the experimental group, a hydroactive dressing was applied to the nasal ala before the surgical procedures; the control group received standard prevention with a type of tape. Skin assessments were performed on the wards up to 72 hours after the procedures. Demographic information and potential contributing factors associated the development of nasal ala pressure injuries were collected from patients' electronic medical records. Pressure injury development was staged using National Pressure Injury Advisory staging guidelines. Pressure injury incidence was compared between groups using the χ test and odds ratio. RESULTS: The sample comprised 450 participants, 225 in each group. The incidence of nasal ala pressure injuries development was 14.222% and 4.444% in the 2 groups, respectively (P = .000). The odds ratio was 3.565 (95% confidence interval, 1.707-7.443). CONCLUSIONS: The study findings indicate that the incidence of pressure injuries of nasal ala skin protected by hydroactive dressings was lower than the standard preventive method. Hydroactive dressings should be considered as a prevention method to reduce device-related skin injuries associated with nasotracheal intubation.

Measuring patient-reported outcomes in orthognathic surgery: Linguistic and psychometric validation of the Mandarin Chinese version of FACE-Q instrument.

BACKGROUND: Orthognathic surgery is useful for correction of dental malocclusion and improvement of facial appearance. The FACE-Q is a patient-reported outcome instrument for evaluation of surgical and psychosocial effect. The purposes of this study were to conduct a linguistic validation of all FACE-Q scales to Mandarin Chinese, to test the orthognathic surgery-related scales for reliability and validity, and to evaluate the effect of orthognathic surgery. METHODS: All FACE-Q scales and checklists were translated from English to Mandarin Chinese according to international recommendations: forward translations, backward translation, and cognitive interviews. Psychometric testing of orthognathic surgery-related scales of translated version was administered to patients with facial deformities and history of orthognathic surgery (n = 53; 17 scales) or no history of orthognathic surgery (n = 44; 11 scales), and control subjects (n = 57; 11 scales). RESULTS: All FACE-Q scales and checklists were linguistically validated into Mandarin Chinese. The contents were confirmed valid among Mandarin Chinese-speaking population. The FACE-Q scales had excellent internal consistency (Cronbach's alpha >0.70) and discriminated (p < 0.05) well between patients before and after orthognathic surgeries and normal subjects. CONCLUSIONS: This study discovered significant benefit of orthognathic surgery on improving facial appearance and psychosocial function, as compared with the non-surgical patients and normal controls.

Evaluating the Effectiveness of Orthognathic Surgery on the Pre-existing Temporomandibular Disorders in Patients with Malocclusion: A Systematic Review and Meta-analysis

Abstract Objective: To evaluate the prevalence of temporomandibular disorders (TMDs) for those patients with dentofacial deformities, who underwent orthognathic surgery, and the control group. It also identified whether orthognathic surgery had a positive or negative impact on TMD symptoms by comparing TMD patients, who underwent orthognathic surgery, and people did not experience this surgery. Finally, this systematic review and meta-analysis aimed to evaluate the effectiveness of orthognathic surgery on the pre-existing TMDs in malocclusion patients. Material and Methods: MEDLINE, PubMed, Cochrane Library, Embase, ISI, google scholar have been utilized as the electronic databases for systematically reviewing the literature between 2001 and February 2019. Inclusion criteria were undergoing orthognathic surgery, patients with/without pre-existing TMDs, and physical disabilities. Results: A total of 669 abstracts and titles with potential relevance have been identified in the course of the manual and electronic searches. It has been found that five studies met our inclusion criteria for a systematic review. Temporomandibular disorders (TMDs) before orthognathic surgery in comparison to the controls (RR=0.02; 95% CI -0.08-0.13) and heterogeneity among the papers has been I2 = 42.86% (p=0.64). Conclusion: Malocclusion by orthognathic and orthodontics surgeries had a considerable rate of TMD compared to the controls.

Comparison of the piezoelectric cutter with a conventional cutting technique in orthognathic surgery.

The use of a piezoelectric cutter has been reported to improve outcomes in orthognathic surgery, particularly with regards to neurosensory disturbance of the inferior alveolar nerve. The aims of this retrospective longitudinal cohort study were to compare outcomes regarding neurosensory disturbance, and operating time. During two 15-month periods a single surgeon treated 24 consecutive patients with a conventional cutting technique and a further 24 consecutive patients with a piezoelectric cutter. In both groups the duration of operation was noted, and neurosensory disturbance graded at 12-month follow up. Neurosensory recovery was better in the piezoelectric group than in the conventional group (p=0.01), and the duration of operation nearly identical. We conclude that the piezoelectric cutter offers advantages with regards to neurosensory deficit over a more conventional technique without the previously-reported disadvantage of a longer operating time.

Real-time augmented model guidance for mandibular proximal segment repositioning in orthognathic surgery, using electromagnetic tracking.

It is essential to reposition the mandibular proximal segment (MPS) as close to its original position as possible during orthognathic surgery. Conventional methods cannot pinpoint the exact position of the condyle in the fossa in real time during repositioning. In this study, based on an improved registration method and a separable electromagnetic tracking tool, we developed a real-time, augmented, model-guided method for MPS surgery to reposition the condyle into its original position more accurately. After virtual surgery planning, using a complex maxillomandibular model, the final position of the virtual MPS model was simulated via 3D rotations. The displacements resulting from the MPS simulation were applied to the MPS landmarks to indicate their final postoperative positions. We designed a new registration body with 24 fiducial points for registration, and determined the optimal point group on the registration body through a phantom study. The registration between the patient's CT image and physical spaces was performed preoperatively using the optimal points. We also developed a separable frame for installing the electromagnetic tracking tool on the patient's MPS. During MPS surgery, the electromagnetic tracking tool was repeatedly attached to, and separated from, the MPS using the separable frame. The MPS movement resulting from the surgeon's manipulation was tracked by the electromagnetic tracking system. The augmented condyle model and its landmarks were visualized continuously in real time with respect to the simulated model and landmarks. Our method also provides augmented 3D coronal and sagittal views of the fossa and condyle, to allow the surgeon to examine the 3D condyle-fossa positional relationship more accurately. The root mean square differences between the simulated and intraoperative MPS models, and between the simulated and postoperative CT models, were 1.71 ± 0.63 mm and 1.89 ± 0.22 mm respectively at three condylar landmarks. Thus, the surgeons could perform MPS repositioning conveniently and accurately based on real-time augmented model guidance on the 3D condyle positional relationship with respect to the glenoid fossa, using augmented and simulated models and landmarks.

A History of Orthognathic Surgery in North America.

This review highlights the contributions of American oral and maxillofacial surgeons to the field of orthognathic surgery. The present state of the art and science of orthognathic surgery is the harvest of yesterday's innovation and research. An improved understanding of the biological and surgical principles and the routine involvement of orthodontics have fueled widespread adoption of a coordinated approach to the treatment of dentofacial problems. Technologic advances in rigid internal fixation, virtual surgical planning with computer-aided manufacturing of occlusal splints and cutting guides, custom implants, and worldwide interest in the correction of dentofacial and craniofacial deformities have resulted in highly predictable, efficient, and safe treatment, which scarcely resembles the situation 70 years ago.

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)

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)

Precisión en la planificación quirúrgica 3D en un paciente con síndrome de Goldenhar / Precision in 3D surgical planning in a patient with Goldenhar syndrome

Objetivo. Presentar un caso clínico de una paciente con síndrome de Goldenhar en el cual se utilizó, para la planificación de la corrección de su asimetría facial, el software Materialise CMF® (Leuven, Bélgica). Caso clínico. aciente de sexo femenino de 27 años que padece síndrome de Goldenhar. Se le realizó cirugía ortognática para corregir su asimetría facial. Para el diagnóstico, planificación y simulación quirúrgica del caso se utilizó el software 3D Materialise CMF® (Leuven, Bélgica). Conclusión. El método de planificación tradicional no es preciso, y estas imprecisiones producen una acumulación de errores en todo el proceso. Estos conceptos cobran gran relevancia en los casos de deformidades asimétricas, en donde los métodos bidimensionales son insuficientes, dejando un gran margen para la intuición, para la habilidad del profesional y, por lo tanto, para el error. El método de planificación 3D facilita el estudio, la planificación y la transferencia de lo planificado a la cirugía, minimizando los errores y logrando la máxima precisión (AU)

Aim. Submit a case of a patient with Goldenhar syndrome. The Materialise CMF® (Leuven, Belgium) software was used for planning her facial asymmetry correction. Case report. Female patient aged 27 who suffers from Goldenhar syndrome. He underwent orthognathic surgery to correct facial asymmetry. For diagnosis, surgical planning and simulation case 3D Materialise CMF® software (Leuven, Belgium) was used. Conclusions. The traditional method of planning is not necessary, these inaccuracies are an accumulation of errors in the whole process. These concepts assume great importance in cases of asymmetric deformities where the 2-dimensional methods are insufficient, leaving much room for intuition, for the professional ability and therefore for error. The method of 3D planning facilitates the study, planning and transfer of what is thought to surgery, minimizing errors and achieving maximum accuracy (AU)

Intraoperative navigation for single-splint two-jaw orthognathic surgery: From model to actual surgery.

OBJECTIVE: This study reported an intraoperative navigation system for single-splint two-jaw orthognathic surgery, and assessed the accuracy of transferring the computer assisted surgical simulation. METHODS: A skull model was used for validation, and twenty patients receiving such procedure were enrolled. The procedure contained five phases, including virtual surgery on three-dimensional images, fabrication of surgical positioning guides, preparation of registration and validation landmarks, confirmation of bony position during surgery, and postoperative assessment. Target registration error (TRE) and differences between simulation (T0) and postoperative images (T1) were measured from landmarks to Frankfort horizontal plane (FHP), mid-sagittal plane (MSP), and coronal plane (COP). RESULTS: For the model experiment, mean TRE was lowest using the hard tissue landmarks (0.60 ± 0.27 mm), and the mean difference (T1-T0) was less than 1 mm to all three planes. For the patients, mean TRE was 1.07 ± 0.18 mm from the hard tissue landmarks. The mean difference was 0.96. ± 0.60 mm from MSP, 1.39 ± 1.11 mm from FHP, and 2.12 ± 1.82 mm from COP. The differences were not significant. Both surgeons and patients were satisfied with the surgical outcome. CONCLUSION: This study showed that the navigation system had acceptable accuracy and was useful for the two-jaw orthognathic surgery using single-splint method.

Keyhole System: A Computer-Assisted Designed and Computer-Assisted Manufactured Maxillomandibular Complex Repositioner in Orthognathic Surgery.

Currently, virtual orthognathic surgery using the CAD/CAM program and three-dimensional printing technology has provided a valuable tool supporting accurate surgical planning and precise surgery. However, despite the advancements in CAD/CAM virtual surgical planning, accurately reproducing surgical planning from a virtual surgery to the operating field is still challenging. Here, we report the Keyhole system as a method that has constantly provided us with consistent results during double-jaw surgery, especially during this age of ever increasing aesthetic demand from patients.

A novel designed screw with enhanced stability introduces new way of intermaxillary fixation.

INTRODUCTION: This article represents new design of a fixation screw-spike screw-for the intermaxillary elastic fixation application after the first surgery in orthognathic surgery. This new type called spike screw is easily placed and provides enough rigidity for the intermaxillary fixation (IMF) with increased stability that was a common problem using screw-type fixation. MATERIALS AND METHODS: Spike screw has a unique design: a washer with soldered stainless hook that adds stability and fixation to the screw done by a miniscrew. It increases stability by reducing the high peak stress-often occurs in miniscrew-and obtaining the advantage of miniplate system with miniscrew fixation. It allows noninvasive screw placement unlike miniplate. The 8 spike screws were placed on the posterior lesion to provide secure IMF, and 2 I-type C-tubes were placed on the anterior lesion. RESULTS: By modifying the length of the hook attached to a washer can accommodate each patient's IMF length variation like a custom-made screw. The stability of the screw was kept well for 6 weeks even with minor gingival irritation in some of the area. This proved that spike screw could be one of the methods for IMF. The closeness of the hook to the teeth eliminated further gingival irritation around the elastic attachment site. Finally, it provided easy manipulation of the hook to change vectors of the elastic force application. CONCLUSIONS: The novel design of the screw permits easy placement and removal for the IMF. In addition, its advantages include increased stability with unique design, less gingival irritation, and simple vector modification of the IMF elastics by adjusting the hook length and shape.

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)

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)

¿Podemos predecir la pérdida de sangre en la cirugía ortognática utilizando parámetros preoperatorios? / Can we predict blood loss during orthognatic surgery using pre-operative paramenters?

El presente artículo estudia la posibilidad de restringir la inclusión de los pacientes sometidos a intervenciones de cirugía ortognática en el protocolo de autotransfusión con predepósitos utilizando parámetros preoperatorios (la mayor edad, el sexo femenino, el tipo de cirugía más invasiva) y valora la necesidad cuantitativa de sangre (número de bolsas utilizadas). Material y método. Realizamos un estudio descriptivo retrospectivo que comprende 91 de intervenciones de cirugía ortognática realizadas entre el junio del 2007 y el diciembre de 2010 en el Hospital de La Princesa - Madrid que describe en términos analíticos el manejo de las pérdidas sanguíneas y busca una relación entre varios parámetros como: edad, tipo de cirugía, tiempo de cirugía, los valores de hemoglobina pre-, intra- y postoperatoria, el número de bolsas de sangre recibidas y el sexo. Resultados. No se han encontrado correlaciones estadísticamente significativas entre la necesidad de transfusión y: la mayor edad (p = 0,23), el sexo femenino (p = 0,11), el mayor tiempo de cirugía (p = 0,93), el tipo de cirugía más invasiva (p = 0,284) con lo cual estos parámetros no suponen un mayor riesgo de sangrado ni de ser transfundido. Conclusión. En nuestro grupo de estudio los parámetros enumerados no sirven en el preoperatorio para delimitar un grupo de pacientes para los cuales la inclusión en el protocolo de autotransfusión sería beneficiosa. Los resultados indican la posibilidad de reducir la cantidad de sangre ahorrada por protocolo e indican una probable sobreindicación del procedimiento(AU)

Objectives: The present article studies the possibility of restricting the inclusion of patients undergoing orthognathic surgical procedures in the autologous transfusion protocol with pre-deposited blood using preoperative parameters (age, female gender, more invasive type of surgery), as well as assessing the amount of blood required (number of bags used). Material and Methods: We conducted a retrospective study comprising 91 orthognathic surgery interventions performed between June 2007 and December 2010 at the La Princesa Hospital - Madrid, which describes, in analytical terms, the management of blood loss and looks for a relationship between various parameters such as age, type of surgery, duration of surgery, pre-, intra- and postoperative haemoglobin values, number of blood bags used and gender. Results: No statistically significant correlationswere found between the need for transfusion and: older age (p = .23), female gender (p = .11), increased duration of surgery (p = .93), the more invasive type of surgery (p = .284), thus these parameters do not pose an increased risk of bleeding or of being transfused. Conclusion: In our study group, the parameters listed in the preoperative evaluation do not serve the purpose of restricting a group of patients for whom the inclusion in the autotransfusion protocolwould be beneficial. The results showthe possibility of reducing the amount of blood saved per protocol and indicate a probable over-recomendation of the procedure(AU)

[Biomaterials in bone repair]. / Biomateriaalit luuston korjauksessa.

In orthopedics, traumatology, and craniofacial surgery, biomaterials should meet the clinical demands of bone that include shape, size and anatomical location of the defect, as well as the physiological load-bearing stresses. Biomaterials are metals, ceramics, plastics or materials of biological origin. In the treatment of large defects, metallic endoprostheses or bone grafts are employed, whereas ceramics in the case of small defects. Plastics are employed on the artificial joint surfaces, in the treatment of vertebral compression fractures, and as biodegradable screws and plates. Porosity, bioactivity, and identical biomechanics to bone are fundamental for achieving a durable, well-bonded, interface between biomaterial and bone. In the case of severe bone treatments, biomaterials should also imply an option to add biologically active substances.

The University Münster Model Surgery System for Orthognathic Surgery. Part II -- KD-MMS.

BACKGROUND: Model surgery is an integral part of the planning procedure in orthognathic surgery. Most concepts comprise cutting the dental cast off its socket. The standardized spacer plates of the KD-MMS provide for a non-destructive, reversible and reproducible means of maxillary and/or mandibular plaster cast separation. METHODS: In the course of development of the system various articulator types were evaluated with regard to their capability to provide a means of realizing the concepts comprised of the KD-MMS. Special attention was dedicated to the ability to perform three-dimensional displacements without cutting of plaster casts. Various utilities were developed to facilitate maxillary displacement in accordance to the planning. Objectives of this development comprised the ability to implement the values established in the course of two-dimensional ceph planning. RESULTS: The system - KD-MMS comprises a set of hardware components as well as a defined procedure. Essential hardware components are red spacer and blue mounting plates. The blue mounting plates replace the standard yellow SAM mounting elements. The red spacers provide for a defined leeway of 8 mm for three-dimensional movements. The non-destructive approach of the KD-MMS makes it possible to conduct different model surgeries with the same plaster casts as well as to restore the initial, pre-surgical situation at any time. Thereby, surgical protocol generation and gnathologic splint construction are facilitated. CONCLUSIONS: The KD-MMS hardware components in conjunction with the defined procedures are capable of increasing efficiency and accuracy of model surgery and splint construction. In cases where different surgical approaches need to be evaluated in the course of model surgery, a significant reduction of chair time may be achieved.