Accuracy of a Computer-Aided Surgical Simulation Protocol for Orthognathic Surgery: A Prospective Multicenter Study (original) (raw)
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Journal of Oral and Maxillofacial Surgery, 2007
Purpose: The purpose of this prospective multicenter study was to assess the accuracy of a computeraided surgical simulation (CASS) protocol for orthognathic surgery. Materials and Methods: The accuracy of the CASS protocol was assessed by comparing planned outcomes with postoperative outcomes of 65 consecutive patients enrolled from 3 centers. Computergenerated surgical splints were used for all patients. For the genioplasty, 1 center used computergenerated chin templates to reposition the chin segment only for patients with asymmetry. Standard intraoperative measurements were used without the chin templates for the remaining patients. The primary outcome measurements were the linear and angular differences for the maxilla, mandible, and chin when the planned and postoperative models were registered at the cranium. The secondary outcome measurements were the maxillary dental midline difference between the planned and postoperative positions and the linear and angular differences of the chin segment between the groups with and without the use of the template. The latter were measured when the planned and postoperative models Received from the Methodist
Accuracy of orthognathic surgery using 3D computer-assisted surgical simulation
Australasian Orthodontic Journal
To evaluate the accuracy of maxilla and mandibular repositioning during two-jaw orthognathic surgery using computerassisted surgical simulation (CASS). Materials and methods: Fifteen patients who underwent two-jaw orthognathic surgery using CASS (VSP ® Orthognathics by 3D Systems) were evaluated to assess the accuracy of the simulation. Translational and rotational discrepancies of the centroids of the maxilla and mandible and the translational discrepancy of the dental midline between the planned and actual outcomes were reported using the root mean square error (RMSE). The number of cases that exceeded limits set for clinical significance, the direction of the error in relation to the direction of planned movement and the differences between segmental and non-segmental procedures were evaluated as secondary outcomes. Results: The largest translational RMSE was 1.53 mm along the y-axis in the maxilla and 1.34 mm along the y-axis in the mandible. The largest rotational RMSE was 1.9° about the x-axis in the maxilla and 1.16° about the x-and y-axes in the mandible. The largest RMSE for the dental midline was 1.6 mm along the y-axis in the maxilla and 1.34 mm along the y-axis in the mandible. A tendency for insufficient advancement of the maxilla was noted. Conclusions: CASS is an efficient and accurate way to develop the surgical plan and transfer the plan to the patient intraoperatively. While CASS is accurate on a population level, there remains the potential for clinically significant errors to occur on an individual basis.
A validation of two orthognathic model surgery techniques-
In order to create an evidence-based orthognathic surgery planning protocol, an investigation of two popular model surgery techniques, the Lockwood keyspacer and the Eastman anatomically-orientated system was carried. This determined (a) the accuracy of positioning of the maxillary cast according to the prescribed treatment plan and (b) the relocation of the maxilla after a simulated Le Fort I down fracture osteotomy using the intermediate wafer as a guide. Fifteen patients-five Class II division 1, five Class II division 2, and five Class III-were included in the study. All the measurements were taken with Erickson's vertically mounted electronic calliper and variations from the treatment plan were analysed.
Computer simulation in the daily practice of orthognathic surgery
International Journal of Oral and Maxillofacial Surgery, 2015
The availability of computers and advances in imaging, especially over the last 10 years, have allowed the adoption of three-dimensional (3D) imaging in the office setting. The affordability and ease of use of this modality has led to its widespread implementation in diagnosis and treatment planning, teaching, and follow-up care. 3D imaging is particularly useful when the deformities are complex and involve both function and aesthetics, such as those in the dentofacial area, and for orthognathic surgery. Computer imaging involves combining images obtained from different modalities to create a virtual record of an individual. In this article, the system is described and its use in the office demonstrated. Computer imaging with simulation, and more specifically patient-specific anatomic records (PSAR), permit a more accurate analysis of the deformity as an aid to diagnosis and treatment planning. 3D imaging and computer simulation can be used effectively for the planning of office-based procedures. The technique can be used to perform virtual surgery and establish a definitive and objective treatment plan for correction of the facial deformity. In addition, patient education and follow-up can be facilitated. The end result is improved patient care and decreased expense.
Journal of cranio-maxillo-facial surgery : official publication of the European Association for Cranio-Maxillo-Facial Surgery, 2017
The main objective of the present study was to assess the accuracy of two- and three-dimensional prediction techniques in orthognathic surgery. It was also a test of the very planning sequence. The scientific question was how well does the software support the surgeon in his way to find the perfect correction of the facial appearance while normalizing the occlusion? Thirty patients with a class III occlusion were included in this prospective study. Surgical planning with both techniques were undertaken for all patients. Surgery was performed according to the two-dimensional technique. The cephalometric measurements from two-dimensional and three dimensional predictions were compared with the postoperative results at the 12 months follow-up respectively. Together with an analysis of tracing error, placements of 2020 markers, 1860 measurements and 1280 comparisons was performed. The analysis showed an equally high accuracy for the studied techniques. The highest accuracy was found in ...
Use of Three-Dimensional Medical Modeling Methods for Precise Planning of Orthognathic Surgery
Journal of Craniofacial Surgery, 2007
Stereolithographic (medical rapid prototyping) biomodeling allows three-dimensional computed tomography to be used to generate solid plastic replicas of anatomic structures. Reports in the literature suggest that such biomodels may have a use in maxillofacial surgery, craniofacial surgery, orthopedics, neurosurgery, otology, vascular, and nasal research. A prospective trial to assess the usefulness of biomodeling in orthognathic surgery has been performed. In 12 patients with mandibular prognathism and/or maxillary retrusion, in addition to routine preoperative cephalometric analysis, preoperative high-resolution (cutting slice thickness of 1 mm) three-dimensional computed tomography scan of the patients was obtained. Raw data obtained from computed tomography scanning was processed with a Mimics 9.22 Software (Materialise's Interactive Medical Image Control System, Belgium). Fabrication of three-dimensional medical models was obtained through a process called powder depositional modeling by use of a Spectrum Z 510 3D Color Printer (Z Corporation, Burlington, MA). Alveolar arches of the maxilla and mandibula of the models were replaced with orthodontic dental cast models. Temporomandibular joints of the models were fixed with Kirschner wire. Maxillary and mandibular bony segments were mobilized according to preoperative orthodontic planning done by analysis of cephalometric plain radiographs. The relation between proximal and distal mandibular segments after bilateral sagittal split osteotomies were eval-uated on models preoperatively. The same surgeon had a role in both model cutting preoperatively and as an instructor preoperatively. The same bony relation was observed both in preoperative models and in the perioperative surgical field in all patients. Condylar malpositioning was not observed in any of the patients. Studying preoperative planned movements of osteotomized bone segments and observing relations of osteotomized segments of mandibula and maxilla in orthognathic surgery increased the intraoperative accuracy. Limitations of this technology were manufacturing time and cost.
PLOS ONE, 2021
Orthognathic surgery is a widely performed procedure to correct dentofacial deformities. Virtual treatment planning is an important preparation step. One advantage of the use of virtual treatment planning is the possibility to assess the accuracy of orthognathic surgery. In this study, a tool (OrthoGnathicAnalyser 2.0), which allows for quantification of the accuracy of orthognathic surgery, is presented and validated. In the OrthoGnathicAnalyser 2.0 the accuracy of the osseous chin can now be assessed which was not possible in the earlier version of the OrthoGnathicAnalyser. 30 patients who underwent bimaxillary surgery in combination with a genioplasty were selected from three different centers in the Netherlands. A pre-operative (CB)CT scan, virtual treatment planning and postoperative (CB)CT scan were required for assessing the accuracy of bimaxillary surgery. The preoperative and postoperative (CB)CT scans were aligned using voxel-based matching. Furthermore, voxel-based matchi...
A New Software Suite in Orthognathic Surgery : Patient Specific Modeling, Simulation and Navigation
Surgical innovation, 2018
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...
Journal of Oral and Maxillofacial Surgery, 2017
The aim of this study was to systematically review methods used for assessing the accuracy of 3-dimensional virtually planned orthognathic surgery in an attempt to reach an objective assessment protocol that could be universally used. Materials and Methods: A systematic review of the currently available literature, published until September 12, 2016, was conducted using PubMed as the primary search engine. We performed secondary searches using the Cochrane Database, clinical trial registries, Google Scholar, and Embase, as well as a bibliography search. Included articles were required to have stated clearly that 3-dimensional virtual planning was used and accuracy assessment performed, along with validation of the planning and/or assessment method. Descriptive statistics and quality assessment of included articles were performed. Results: The initial search yielded 1,461 studies. Only 7 studies were included in our review. An important variability was found regarding methods used for 1) accuracy assessment of virtually planned orthognathic surgery or 2) validation of the tools used. Included studies were of moderate quality; reviewers' agreement regarding quality was calculated to be 0.5 using the Cohen k test. Conclusions: On the basis of the findings of this review, it is evident that the literature lacks consensus regarding accuracy assessment. Hence, a protocol is suggested for accuracy assessment of virtually planned orthognathic surgery with the lowest margin of error.