A new design of CAD/CAM surgical template system for two-piece narrowing genioplasty

Feasibility of augmented reality combine patient-specific implants (PSI) applied to navigation in mandibular genioplasty: A phantom experiment

PURPOSE

Genitoplasty is becoming more and more common, and it is important to improve the accuracy of the procedure and simplify the procedure. This experiment explores the feasibility of using augmented reality (AR) technology combined with PSI titanium plates for navigational assistance in genioplasty performed on models, aiming to study the precision of such surgical interventions.

METHODS

Twelve genioplasty procedures were designed and implemented on 3D-printed resin mandibular models by the same surgeon using three different approaches: AR+3DT group (AR+PSI) , 3DT group (patient-specific titanium plate) , and a traditional free-hand group(FH group). Postoperative models were assessed using CBCT to evaluate surgical accuracy.

RESULTS

In terms of osteotomy accuracy, the AR group demonstrated a surgical error of 0.9440±0.5441 mm, significantly lower than the control group, which had an error of 1.685±0.8907 mm (P < 0.0001). In experiments positioning the distal segment of the chin, the overall centroid shift in the AR group was 0.3661±0.1360 mm, significantly less than the 2.304±0.9629 mm in the 3DT group and 1.562±0.9799 mm in the FH group (P < 0.0001). Regarding angular error, the AR+3DT group showed 2.825±1.373°, significantly <8.283±3.640° in the 3DT group and 7.234±5.241° in the FH group.

CONCLUSION

AR navigation technology combined with PSI titanium plates demonstrates higher surgical accuracy compared to traditional methods and shows feasibility for use. Further validation through clinical trials is necessary.

A novel portable augmented reality surgical navigation system for maxillofacial surgery: technique and accuracy study

Surgical navigation, despite its potential benefits, faces challenges in widespread adoption in clinical practice. Possible reasons include the high cost, increased surgery time, attention shifts during surgery, and the mental task of mapping from the monitor to the patient. To address these challenges, a portable, all-in-one surgical navigation system using augmented reality (AR) was developed, and its feasibility and accuracy were investigated. The system achieves AR visualization by capturing a live video stream of the actual surgical field using a visible light camera and merging it with preoperative virtual images. A skull model with reference spheres was used to evaluate the accuracy. After registration, virtual models were overlaid on the real skull model. The discrepancies between the centres of the real spheres and the virtual model were measured to assess the AR visualization accuracy. This AR surgical navigation system demonstrated precise AR visualization, with an overall overlap error of 0.53 ± 0.21 mm. By seamlessly integrating the preoperative virtual plan with the intraoperative field of view in a single view, this novel AR navigation system could provide a feasible solution for the use of AR visualization to guide the surgeon in performing the operation as planned.

Guided Genioplasty: Comparison between Conventional Technique and Customized Guided Surgery

BACKGROUND

Genioplasty as an isolated surgical technique is a highly demanded procedure in the maxillofacial surgery area. Advances in facial reconstructive surgery have been associated with less morbidity and more predictable results. In this paper, "conventional" genioplasty and genioplasty by means of virtual surgical planning (VSP), CAD-CAM cutting guides, and patient custom-made plates are compared.

METHODS

A descriptive observational study was designed and implemented, and 43 patients were treated, differentiating two groups according to the technique: 18 patients were treated by conventional surgery, and 25 patients were treated through virtual surgical planning (VSP), CAD-CAM cutting guides, STL models, and titanium patient-specific plates.

RESULTS

The operation time ranged from 35 to 107 min. The mean operative time in the conventional group was 60.06 + 3.74 min.; in the custom treatment group it was 42.24 + 1.29 min (p < 0.001). The difference between planned and obtained chin changes in cases of advancement or retrusion was not statistically significant (p = 0.125; p = 0.216). In cases of chin rotation due to asymmetry, guided and personalized surgery was superior to conventional surgery (p < 0.01). The mean hospital stay was equal in both groups. A decrease in surgical complications was observed in the group undergoing VSP and customized treatment.

CONCLUSIONS

Multi-stage implementation of VSP with CAD-CAM cutting guides, STL models, and patient-specific plates increased the accuracy of the genioplasty surgery, particularly in cases of chin asymmetry, reducing operation time and potential complications.

Exploring the distribution of visual attention in genioplasty trainees using eye-tracking technology

PURPOSE

This study aimed to investigate the visual attention of genioplasty trainees using eye-tracking technology, with the goal of providing insights for optimizing genioplasty training strategies.

METHODS

Trainees were recruited for the study, and their visual attention distribution was monitored with an eye-tracking device while they watched a genioplasty procedure video. The percentage of fixation durations dedicated to areas of interest (surgical objects, instruments manipulated by the primary surgeon, and instruments controlled by assistants) were analyzed for each phase of the procedure.

RESULTS

A total of 20 surgical trainees (8 males, 12 females; mean age, 27.8 years; range, 22-35 years) participated in the study. During the soft tissue reflection phase, trainees' percentage fixation durations on instruments controlled by the primary surgeon were higher than on surgical objects, but the difference was not significant (p > 0.05). The percentage fixation durations on instruments controlled by assistants were significantly lower than on those controlled by the primary surgeon or on surgical objects (p < 0.05). In the osteotomy, bone fixation, and suturing phases, the percentage fixation durations on surgical objects were highest, followed by instruments manipulated by the primary surgeon and those controlled by assistants, with significant differences (p < 0.05).

CONCLUSION

Surgical trainees need to invest significant cognitive effort in focusing on the instruments manipulated by the primary surgeon and the surgical objects during the soft tissue reflection phase, as well as on surgical objects during the osteotomy, fixation, and suturing phases. Emphasizing these elements during instruction can help trainees reduce their cognitive load and effectively master genioplasty techniques.

From "Empirical Surgery" to "Precision Surgery": establishment and clinical application of precision orthognathic surgery system

Orthognathic surgery, which involve osteotomy and repositioning of the maxillomandibular complex, has recently emerged as a crucial method of correcting dentofacial deformities. The optimal placement of the maxillomandibular complex holds utmost significance during orthognathic surgery because it directly affects the surgical outcome. To accurately achieve the ideal position of the maxillomandibular complex, with the rapid advancements in digital surgery and 3D-printing technology, orthognathic surgery has entered an era of "Precision Surgery" from the pervious "Empirical Surgery." This article provides comprehensive insights into our extensive research and exploration of the treatment modality known as "precision orthognathic surgery" over the years. We also present the technical system and application in"Ortho+X" treatment modality to offer valuable references and assistance to our colleagues in the field.

Application of digital guide plate based on drill-hole sharing in oral and maxillofacial surgery

OBJECTIVES

This study aimed to investigate the application of digital guide plate based on the drill-hole sharing concept in orthognathic surgery and mandibular reconstruction.

METHODS

Sixteen patients with maxillofacial deformity requiring orthognathic surgery and 10 patients requiring mandibular reconstruction were selected as the research objects. Patients with maxillofacial deformity were scanned by computed tomography (CT), gypsum mold of the maxilla and mandibular arch were scanned using a laser surface scanner, and the fibula or iliac bone of the patients who needed mandibular reconstruction were scanned by CT to create a 3D model. The osteotomy and repositioning guides based on the drill-hole sharing concept were manufactured by digital technology. The guide plate was used to guide osteotomy and reposition the bone segment. Postoperative CT scan was performed. The displacement error of the bone segment was compared between the preoperative virtual surgery and the actual surgery to evaluate the accuracy of the guide plate, by measuring the distance between the landmarks and three reference planes and the distance between the two landmarks.

RESULTS

The wounds healed well in all patients, and no serious complications were observed. The maximum mean values of LeFort Ⅰ osteotomy, genioplasty, fibular reconstruction, and iliac reconstruction were 0.84, 0.64, 1.27, and 1.18 mm, respectively; these values were acceptable by clinical standards.

CONCLUSIONS

The digital guide plate based on the drill-hole sharing concept has high accuracy and clinical application value in orthognathic surgery and mandibular reconstruction.

Establishing a point-of-care additive manufacturing workflow for clinical use

Additive manufacturing, or 3-Dimensional (3-D) Printing, is built with technology that utilizes layering techniques to build 3-D structures. Today, its use in medicine includes tissue and organ engineering, creation of prosthetics, the manufacturing of anatomical models for preoperative planning, education with high-fidelity simulations, and the production of surgical guides. Traditionally, these 3-D prints have been manufactured by commercial vendors. However, there are various limitations in the adaptability of these vendors to program-specific needs. Therefore, the implementation of a point-of-care in-house 3-D modeling and printing workflow that allows for customization of 3-D model production is desired. In this manuscript, we detail the process of additive manufacturing within the scope of medicine, focusing on the individual components to create a centralized in-house point-of-care manufacturing workflow. Finally, we highlight a myriad of clinical examples to demonstrate the impact that additive manufacturing brings to the field of medicine.

Three-dimensional comparative evaluation of customized bone-anchored vs tooth-borne maxillary protraction in patients with skeletal Class III malocclusion

INTRODUCTION

The aim of this prospective study was to assess the 3-dimensional skeletal and dental effects induced by a new maxillary protraction approach using customized miniplates for anchorage compared with a control group of traditional tooth-borne maxillary protraction.

METHODS

Forty-one growing patients at prepubescent stage with skeletal Class III malocclusion participated in this study. These patients were randomly split into 2 groups. In group 1 (n = 20), patients underwent maxillary protraction anchored with customized miniplates. The miniplates were individually designed and inserted using the surgical templates. In group 2 (n = 21), patients underwent tooth-borne maxillary protraction. Pretreatment and posttreatment cone-beam computed tomography scans were obtained, and 30 measurements of cone-beam computed tomography images were acquired and calculated. The changes after treatment and the comparison of the 2 groups were assessed.

RESULTS

After maxillary protraction, group 1 showed a greater forward movement of the maxilla than group 2. The maxilla length increased more in group 1 than in group 2. The rotations of the palatal and mandibular planes in group 1 were less than those in group 2. In group 1, the maxillary incisors proclined less, the mandibular incisors retroclined less, and the maxillary first molars extruded less.

CONCLUSIONS

Compared with tooth-borne maxillary protraction, customized miniplates anchored maxillary protraction produced more maxillary growth, fewer dental changes, and less maxillary and mandibular plane rotation.

Mandibular Reconstruction Using Free Fibular Flap Graft Following Excision of Calcifying Epithelial Odontogenic Tumor

ABSTRACT

The calcifying epithelial odontogenic tumor (CEOT) is a rare benign odontogenic tumor, which usually presents with distension of affected tissues. Radiologically, the lesions are often associated with an unerupted tooth and may have spot calcification shadows. The authors report a case of a CEOT in a 48-year-old male involving the right mandibular jaw bone and mentum soft tissues. The authors performed hemimandibulectomy and enucleation followed by reconstruction of the mandible using a vascularized free fibular flap through a digital surgical technique in order to restore the patient's facial symmetry and prepare the area for functional restorations. The case illustrates who the free fibular flap graft can be used for satisfactory mandibular reconstruction and restoration of the morphology and functions.

Virtual Reality (VR) Simulation and Augmented Reality (AR) Navigation in Orthognathic Surgery: A Case Report

VR and AR technology have gradually developed to the extent that they could help operators in the surgical field. In this study, we present a case of VR simulation for preoperative planning and AR navigation applied to orthognathic surgery. The average difference between the preplanned data and the post-operative results was 3.00 mm, on average, and the standard deviation was 1.44 mm. VR simulation could provide great advantages for 3D medical simulations, with accurate manipulation and immersiveness. AR navigation has great potential in medical application; its advantages include displaying real time augmented 3D models of patients. Moreover, it is easily applied in the surgical field, without complicated 3D simulations or 3D-printed surgical guides.

Computer-assisted horizontal translational osseous genioplasty: a simple method to correct chin deviation

Background

Different genioplasty techniques are applied for the adjustment of chin area deformities such as chin deviation.

Results

Thirty patients with simple facial asymmetry due to chin deviation underwent computer-assisted horizontal translational osseous genioplasty. In this technique, a surgical guide was used to cut a bone strip from the side where the chin should be transferred to; then, the same bone strip was used for the filling of the gap that was formed on the opposite side.

Conclusion

According to the experience gained from this study, the authors believe that computer-assisted horizontal translational osseous genioplasty is a simple and reliable technique for patients with facial asymmetry due to chin deviation.

The Minimally Invasive-Guided Genioplasty Technique using Piezosurgery and 3D printed surgical guide: An innovative technique

Introduction

Mental nerve injuries with neurosensory deficits, asymmetries, and intra-operative bleeding are the main immediate complications of genioplasty. Following a recent systematic review, three-dimensional (3D)-printed cutting guide could improve the predictability and accuracy of this surgical technique avoiding postoperative asymmetries. Furthermore, anatomical structures in the surgical area (mental nerve and teeth roots) are better protected, reducing the morbidity and providing safer results. Ultrasonic piezoelectric osteotomy allows by its intrinsic characteristics, a selective cut of mineralized structure with a lower risk of vascular and nervous damage (microvibrations), intra-operative precision (thin cutting scalpel and no macro-vibrations), and blood-free site (cavitation effect). The aim of this article is to present a new minimally invasive technique: the minimally invasive-guided genioplasty technique (aka MIGG technique). This technique combines the advantages of piezosurgery and of a space-saving 3D-printed cutting guide, requiring open-source programs and an affordable 3D printing technology.

Materials and Methods

All the steps of this technique are described: preoperative surgical planning (CT scanner, segmentation with 3D slicer®, and design of the cutting guide with Blender®) and 3D printing of the guide and sterilization of it. The surgical procedure is presented in detail as well as the postoperative care.

Conclusion

The MIGG technique offers, according to the authors, a better postoperative recuperation, a reduction in operating time, less complications, and protection of the anatomical structures (mental nerve, teeth, lingual soft tissue and vessels). This minimally invasive technique for genioplasty is a promising approach to perform a chin osteotomy.

Design and manufacture of dental-supported surgical guide for genioplasty

Background/purpose

Genioplasty were used widely to correct chin deformities. The purpose of this study was to design and manufacture a dental-supported surgical guide for genioplasty surgery and assess for surgical accuracy.

Materials and methods

eleven patients with chin deformities were treated in this study. The computed tomography (CT) data of the patient's skull and the digital dental models of stone dental models were acquired preoperatively. For each patient, a virtual three-dimensional (3D) model of the skull was constructed and enhanced with digital dental models. A surgical simulation was then performed using computer-aided surgical simulation (CASS) technology based on clinical examination and 3D cephalometry. The surgery was simulated preoperatively which allowed the design of a cutting guide and a dental-supported repositioning guide for genioplasty, which was then 3D-printed and used during operation after disinfection. After surgery, the outcome was evaluated by superimposing the postoperative CT model onto the preoperative model, recording the linear and angular deviation of landmarks and plane, then measuring the differences between the planned and actual outcomes.

Results

The osteotomy and repositioning were successfully performed as planned using surgical guides. No inferior alveolar nerve damage was seen in this study. The dental-supported surgical guide showed excellent accuracy, with the largest differences between the planned and the postoperative chin segment being 0.9 mm and 3.2°.

Conclusion

The dental-supported surgical guide designed preoperatively provided a reliable method of transfer genioplasty planning. This can assist surgeons in accurately performing osteotomy and repositioning bone segments during a genioplasty.

Genioplasty with surgical guide using 3D-printing technology: A systematic review

Background

The purpose of this systematic review is to evaluate the current state of the art of making genioplasties using 3D printing technology.

Material and Methods

A multi-database single-reviewer systematic review identified sixteen papers that fulfilled the selection criteria. There were mainly case series and case reports available (Level IV of the Oxford Evidence-based medicine scale); only two prospective study (Level III) evaluated this subject. These articles are analyzed in details and summarized in this review.

Results

The realization of genioplasties with surgical guide using 3D-printing technology could improve predictability and accuracy. It protects anatomical structures in the environment of the surgery, reducing by this way the morbidity and providing safer results. The type of printer and material used as well as the sterilization techniques should be further developed by the authors. The use of open-access software should also be further explored to allow the use of these new technologies by the largest number of surgeons.

Conclusions

Finally, prospective multi-center studies with larger samples should be performed to definitively conclude the benefits of this new technology and allow for its routine use. This article is the first systematic review on this topic. Key words:Genioplasty, printing, three-dimensional, surgery, computer-assisted.

Clinical Study on the Minimally Invasive-Guided Genioplasty Using Piezosurgery and 3D Printed Surgical Guide

INTRODUCTION

A retrospective clinical study was performed regarding the minimally invasive-guided genioplasty technique (MIGG technique) described in a previous clinical note. The aims of this clinical study were to study the incidence of immediate complications with this technique compared with a control group using a nonminimally genioplasty technique, to validate the accuracy of the three-dimensional (3D) printed cutting guide, and to evaluate the duration of the surgery and the satisfaction of the surgeons with this technique.

MATERIALS AND METHODS

One controlled group, including 56 patients, operated with a classical genioplasty and one group, including 24 patients operated with the MIGG technique. The inclusion criteria were patients from 18 years old benefiting from orthognathic surgery for dysmorphic maxillofacial disorders, sleep apneas, or posttraumatic malocclusion; operated by the three same surgeons. A database was retrospectively made, including the demographics parameters, the indication, the type and the duration of surgery, the incidence of complication, and the type of complication. The accuracy of the cutting guide was also studied by the comparison of two distances in the MIGG group on the preoperative surgical simulation and on the postoperative cephalometric radiography. A satisfaction survey for the surgeons of the department regarding the MIGG technique was also analyzed.

CONCLUSION

No statistical difference was found in the incidence of complications between the MIGG group and the control group. Using a guide does not cause more surgical infection. The protection of the inferior alveolar nerve is obvious. The absence of statistical difference is due to the fact that the majority of patients also benefited from the bilateral sagittal split osteotomy during surgery. The 3D-cutting guide used is very accurate: There is indeed no significative difference in the measurements A and B before and after the genioplasty. The MIGG technique is thus a predictable, safe, and easy-to-use technique that should be used routinely by maxillofacial surgeons. It combines the latest technologies in piezosurgery and in 3D-guided surgery by the creation of a validated-accurate 3D-printed cutting guide. This technique is affordable by the use of open-source program and a desktop fused deposit Modeling 3D-printer. Finally, the comfort of the surgeon is improved, and the operating time is decreased.

A Modified Method Using Double Computed Tomography Scan Procedure to Maintain Mandibular Width in Mandibular Reconstruction

OBJECTIVE

The purpose of this study was to evaluate the use of a modified template system and double computed tomography scan procedure to maintain mandibular width in cases of mandibular reconstruction.

STUDY DESIGN

Ten patients who underwent mandibular reconstruction with a fibular flap were enrolled. The surgeries were planned with a computer-aided surgical simulation (CASS) planning method. Following double computed tomography scan procedure, the template system was designed in a computer and was fabricated using a three-dimensional printing technique. The cutting guides were designed with the holes of the conventional reconstruction plate on the remnant mandibular segments. After surgery, the outcome evaluation was compared by first superimposing the post-operative computed tomography model onto the planned model and then measuring the differences between the planned and actual outcomes.

RESULTS

All surgeries were completed successfully using the template system. With the use of the templates, the largest linear root-mean-square deviation (RMSD) between the planned and post-operative remnant segments was 1.01 mm, and the largest angular RMSD was 4.05°.

CONCLUSIONS

The authors conclude that this template system and double computed tomography scan procedure provides a reliable method to maintain mandibular width in mandibular reconstruction using a fibular flap.

The use of patient-specific implants in genioplasty and its clinical accuracy: a preliminary study

The purpose of this study was to assess the accuracy and clinical validation of patient-specific implants (PSI) in genioplasty. Fifteen patients with chin deformities were enrolled. Virtual planning was performed with the computer-aided surgical simulation method. The three-dimensional-printed titanium cutting guide and patient-specific plate were designed to guide the osteotomy and allow repositioning and fixation of the chin. The outcome was evaluated by comparing the plan with actual outcomes. All operations were successfully completed with PSIs. There was no difficulty in using patient-specific plates. The largest root-mean-square difference of the chin position was 0.69 mm in mediolateral translation and 2.01° in the yaw orientation. The results of the study indicated that the PSI technique was an accurate method of transferring the virtual plan to the operation field with great efficiency in genioplasty. A significant advantage of the PSI technique is that the patient-specific plate could simultaneously complete the repositioning and fixation of the chin. Intraoperative measurements and reposition guides were no longer required. Operative procedures were greatly simplified.

A reversed approach for simultaneous mandibular symphyseal split osteotomy and genioplasty

Performing a mandibular symphyseal split and genioplasty simultaneously and accurately is a technical challenge for the surgeon. The aim of this study was to validate a reversed approach for simultaneous symphyseal split and genioplasty. A cutting guide and a repositioning guide were designed and printed three-dimensionally in titanium. The symphyseal split and genioplasty were performed successfully. The accuracy of the technique appears to be appropriate for clinical application.

Toward a higher accuracy in orthognathic surgery by using intraoperative computer navigation, 3D surgical guides, and/or customized osteosynthesis plates: A systematic review

The aim of this study was to systematically review the accuracy of intraoperative computer navigation, three-dimensional surgical guides and customized osteosynthesis plates for the transfer of the virtual surgical plan to the patient in orthognathic surgery. A systematic review of the currently available publications was performed in databases MEDLINE, Embase, and Cochrane Library, using a PICOS search strategy, and reported according to PRISMA. The initial search yielded 3050 articles. In total, 16 studies were included for final quantitative analyses. The results of individual studies demonstrated a comparable accuracy in the transfer of planned surgical displacement of the jaws. A large variability was found with regard to the method of accuracy assessment and reported outcomes. The findings of this review show that these modern techniques have the potential to replace interocclusal splints in routine clinical practice in the future. We recommend that authors presenting new data on the accuracy of a technique should choose the method of accuracy assessment meticulously, acquiring postoperative imaging as soon as possible after surgery. They should report as much as possible, summarizing values or, ideally, even the raw data of the accuracy assessment in order to allow comparison with other techniques in a meta-analysis.

A New Proposal for Three-Dimensional Positioning of the Chin Using a Single Computer-Aided Design/Computer-Aided Manufacturing Surgical Guide

The workflow digital to aid the treatment of dentofacial deformities is a reality. Associated with the virtual planning, the creation of surgical guides assists the performance of osteotomies and bone positioning, increasing the accuracy of surgical outcomes. This study aims to present a new method of surgical guide for genioplasty based on the selected osteosynthesis plate.

Application of A Novel Three-dimensional Printing Genioplasty Template System and Its Clinical Validation: A Control Study

The purpose of this control study was to assess the accuracy and clinical validation of a novel genioplasty template system. Eighty-eight patients were enrolled and divided into 2 groups: experimental group (using genioplasty templates) and control group (without genioplasty templates). For the experimental group, the templates were designed based on computerized surgical plan and manufactured using three-dimensional printing technique. The template system included a cutting guide and a pair of repositioning guides. For the control group, traditional intraoperative measurements were used without genioplasty templates. The outcome evaluation was completed by comparing planned outcomes with postoperative outcomes. Linear and angular differences for the chin was measured and reported using root mean square deviation (RMSD) and the Bland-Altman method. All surgeries were successfully completed. There was no difficulty to use genioplasty templates. For the experimental group, the largest RMSDs were 1.1 mm in anteroposterior direction and 2.6° in pitch orientation. For the control group without templates, the largest RMSDs were 2.63 mm in superoinferior direction and 7.21° in pitch orientation. Our findings suggest that this genioplasty template system provides greater accuracy in repositioning the chin than traditional intraoperative measurements, and the computerized plan can be transferred accurately to the patient for genioplasty.

A new approach of splint-less orthognathic surgery using a personalized orthognathic surgical guide system: A preliminary study

The purpose of this study was to evaluate a personalized orthognathic surgical guide (POSG) system for bimaxillary surgery without the use of surgical splint. Ten patients with dentofacial deformities were enrolled. Surgeries were planned with the computer-aided surgical simulation method. The POSG system was designed for both maxillary and mandibular surgery. Each consisted of cutting guides and three-dimensionally (3D) printed custom titanium plates to guide the osteotomy and repositioning the bony segments without the use of the surgical splints. Finally, the outcome evaluation was completed by comparing planned outcomes with postoperative outcomes. All operations were successfully completed using the POSG system. The largest root-mean-square deviations were 0.74mm and 1.93° for the maxillary dental arch, 1.10mm and 2.82° for the mandibular arch, 0.83mm and 2.59° for the mandibular body, and 0.98mm and 2.45° for the proximal segments. The results of the study indicated that our POSG system is capable of accurately and effectively transferring the surgical plan without the use of surgical splint. A significant advantage is that the repositioning of the bony segments is independent to the mandibular autorotation, thus eliminates the potential problems associated with the surgical splint.

Design, development and clinical validation of computer-aided surgical simulation system for streamlined orthognathic surgical planning

PURPOSE

There are many proven problems associated with traditional surgical planning methods for orthognathic surgery. To address these problems, we developed a computer-aided surgical simulation (CASS) system, the AnatomicAligner, to plan orthognathic surgery following our streamlined clinical protocol.

METHODS

The system includes six modules: image segmentation and three-dimensional (3D) reconstruction, registration and reorientation of models to neutral head posture, 3D cephalometric analysis, virtual osteotomy, surgical simulation, and surgical splint generation. The accuracy of the system was validated in a stepwise fashion: first to evaluate the accuracy of AnatomicAligner using 30 sets of patient data, then to evaluate the fitting of splints generated by AnatomicAligner using 10 sets of patient data. The industrial gold standard system, Mimics, was used as the reference.

RESULT

When comparing the results of segmentation, virtual osteotomy and transformation achieved with AnatomicAligner to the ones achieved with Mimics, the absolute deviation between the two systems was clinically insignificant. The average surface deviation between the two models after 3D model reconstruction in AnatomicAligner and Mimics was 0.3 mm with a standard deviation (SD) of 0.03 mm. All the average surface deviations between the two models after virtual osteotomy and transformations were smaller than 0.01 mm with a SD of 0.01 mm. In addition, the fitting of splints generated by AnatomicAligner was at least as good as the ones generated by Mimics.

CONCLUSION

We successfully developed a CASS system, the AnatomicAligner, for planning orthognathic surgery following the streamlined planning protocol. The system has been proven accurate. AnatomicAligner will soon be available freely to the boarder clinical and research communities.

Surgical applications of three-dimensional printing: a review of the current literature & how to get started

Three dimensional (3D) printing involves a number of additive manufacturing techniques that are used to build structures from the ground up. This technology has been adapted to a wide range of surgical applications at an impressive rate. It has been used to print patient-specific anatomic models, implants, prosthetics, external fixators, splints, surgical instrumentation, and surgical cutting guides. The profound utility of this technology in surgery explains the exponential growth. It is important to learn how 3D printing has been used in surgery and how to potentially apply this technology. PubMed was searched for studies that addressed the clinical application of 3D printing in all surgical fields, yielding 442 results. Data was manually extracted from the 168 included studies. We found an exponential increase in studies addressing surgical applications for 3D printing since 2011, with the largest growth in craniofacial, oromaxillofacial, and cardiothoracic specialties. The pertinent considerations for getting started with 3D printing were identified and are discussed, including, software, printing techniques, printing materials, sterilization of printing materials, and cost and time requirements. Also, the diverse and increasing applications of 3D printing were recorded and are discussed. There is large array of potential applications for 3D printing. Decreasing cost and increasing ease of use are making this technology more available. Incorporating 3D printing into a surgical practice can be a rewarding process that yields impressive results.