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Surgical interventions for jaw reconstruction require the design and the production of surgical guides that allow the surgeon to operate quickly and accurately. In some cases, the reconstruction is performed by inserting a prothesis, thus operating exclusively on the jaw, while in other cases the reconstruction is performed by withdrawing and inserting part of the fibula in place of the original jaw bone. This project aims to develop a procedure that allows 3D modeling of the surgical guides necessary for surgical intervention. The idea is to find a surgical guide archetype, a starting shape for the surgeon so that the cutting planes can be oriented without the surgical guide having to be redesigned from scratch for every single patient. The first step of the procedure is the segmentation, performed applying the thresholding operation on the images provided by magnetic resonance MR in order to identify the region of interest (ROI). The second step is the reconstruction of the 3D model, so that a mesh is obtained from 2D images. Subsequently the mesh is post-processed and the cutting plans along which the surgeon will intervene are defined.

International audience; Three-dimensional (3D) printing is booming in the medical field. This technology increases the possibilities of personalized treatment for patients, while lowering manufacturing costs. To facilitate mandibular reconstruction with fibula free flap, some companies propose cutting guides obtained by CT-guided moulding. However, these guides are prohibitively expensive (€2,000 to €6,000). Based on a partnership with the CNRS, engineering students and a biomedical company, the authors have developed cutting guides and 3D-printed mandible templates, deliverable in 7days and at a lower cost. The novelty of this project is the speed of product development at a significantly lower price. In this technical note, the authors describe the logistic chain of production of mandible templates and cutting guides, as well as the results obtained. The goal is to allow access to this technology to all patients in the near future.

Objectives: The purpose of this study was to assess the accuracy of computer-assisted implant insertion based on computed tomography and template-guided implant placement. Material and methods: A total of 246 implants were placed with the aid of 3D-based transfer templates in 181 consecutive partially edentulous patients. Five groups were formed on the basis of different implant systems, surgical protocols and guide sleeves. After virtual implant planning with the CoDiagnostiX Software, surgical guides were fabricated in a dental laboratory. After implant insertion, the actual implant position was registered intraoperatively and transferred to a model cast. Deviations between the preoperative plan and postoperative implant position were measured in a follow-up computed tomography of the patient’s model casts and image fusion with the preoperative computed tomography. Results: The median deviation between preoperative plan and postoperative implant position was 1.0 mm at the implant shoulder and 1.4 mm at the implant apex. The median angular deviation was 3.6º. There were significantly smaller angular deviations (P=0.000) and significantly lower deviations at the apex (P=0.008) in implants placed for a single-tooth restoration than in those placed at a free-end dental arch. The location of the implant, whether in the upper or lower jaw, did not significantly affect deviations. Increasing implant length had a significant negative influence on deviations from the planned implant position. There was only one significant difference between two out of the five implant systems used. Conclusion: The data of this clinical study demonstrate the accuracy and predictable implant placement when using laboratory-fabricated surgical guides based on computed tomography., Zielsetzung: Ziel der vorliegenden klinischen Untersuchung war die Evaluation der klinischen Genauigkeit schablonengestützter Implantationen mit laborgefertigten Bohrschablonen auf Basis dreidimensionaler Bildgebung. Material und Methoden: Es wurden insgesamt 246 Implantate mit laborgefertigten Bohrschablonen auf Basis einer dreidimensionaler Bildgebung in 181 teilbezahnten Patienten inseriert. Die inserierten Implantate wurden in Abhängigkeit vom verwendeten Implantatsystem, dem chirurgischen Protokoll und den verwendeten Hülsen in fünf unterschiedliche Gruppen eingeteilt. Nach dreidimensionaler Implantatplanung mit der Software CoDiagnostiX wurden im zahntechnischen Labor Bohrschablonen hergestellt. Nach Implantatinsertion wurde die aktuelle Implantatposition intraoperativ registriert und auf ein Gipsmodell des Patienten übertagen. Durch die Bildfusion der präoperativen Implantatplanung mit der dreidimensionalen Bildgebung des Gipsmodells konnten die Abweichungen zwischen geplanter und erzielter Implantatposition berechnet werden. Ergebnisse: Der Median der Abweichungen zwischen geplanter und erreichter Implantatposition war 1 mm an der Implantatbasis und 1,4 mm an der Implantatspitze. Der Median der Achsenabweichung lag bei 3,6º. Implantate, welche in einer Schaltlücke gesetzt worden waren, zeigten statistisch signifikant kleinere Achsenabweichungen (P=0.000) und geringere Abweichungen an der Implantatspitze (P=0.008) im Vergleich zu Implantaten, welche in einer Freiendsituation inseriert wurden. Es zeigte sich keine Abhängigkeit der Genauigkeit von einer Implantation im Oberkiefer oder Unterkiefer. Die zunehmende Implantatlänge wirkte sich negativ auf die Genauigkeit der erreichten Implantatposition auf. In Abhängigkeit vom Implantatsystem ergab sich ein statistisch signifikanter Unterschied ausschließlich zwischen zwei Systemen. Schlussfolgerung: Die vorliegende klinische Untersuchung konnte die hohe Präzision und Verlässlichkeit einer schablonengeführten Implantatinsertion nach computerassistierter Planung belegen., GMS Interdisciplinary Plastic and Reconstructive Surgery DGPW; 5:Doc15

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. 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.

Objective To evaluate the reliability and accuracy of computer-designed surgical guides in osseointegrated oral implant rehabilitation. Materials and methods Six implant rehabilitations, with a total of 17 implants, were completed with computer-designed surgical guides, performed with the master model developed by muco-compressive and muco-static impressions. In the first case, the surgical guide had exclusively mucosal support, in the second case exclusively dental support. For all six cases computer-aided surgical planning was performed by virtual analyses with 3D models obtained by dental scan DICOM data. The accuracy and stability of implant osseointegration over two years post surgery was then evaluated with clinical and radiographic examinations. Radiographic examination, performed with digital acquisitions (RVG – Radio Video graph) and parallel techniques, allowed two-dimensional feedback with a margin of linear error of 10%. Results Implant osseointegration was recorded for all the examined rehabilitations. During the clinical and radiographic post-surgical assessments, over the following two years, the peri-implant bone level was found to be stable and without appearance of any complications. The margin of error recorded between pre-operative positions assigned by virtual analysis and the post-surgical digital radiographic observations was as low as 0.2 mm. Significance Computer-guided implant surgery can be very effective in oral rehabilitations, providing an opportunity for the surgeon: (a) to avoid the necessity of muco-periosteal detachments and then (b) to perform minimally invasive interventions, whenever appropriate, with a flapless approach.

ResumenLa 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.AbstractOrthognathic 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.