Artificial Intelligence Splint in Orthognathic Surgery for Skeletal Class III Malocclusion: Design and Application.

BACKGROUND: Digital splints are indispensable in orthognathic surgery. However, the present design process of splints is time-consuming and has low reproducibility. To solve these problems, an algorithm for artificial intelligent splints has been developed in this study, making the automatic design of splints accessible. METHODS: Firstly, the algorithm and program of the artificial intelligence splint were created. Then a total of 54 patients with skeletal class III malocclusion were included in this study from 2018 to 2020. Pre and postoperative radiographic examinations were performed. The cephalometric measurements were recorded and the difference between virtual simulation and postoperative images was measured. The time cost and differences between artificial intelligent splints and digital splints were analyzed through both model surgery and radiographic images. RESULTS: The results showed that the efficiency of designing splints is significantly improved. And the mean difference between artificial intelligent splints and digital splints was <0.15 mm in model surgery. Meanwhile, there was no significant difference between the artificial intelligent splints and digital splints in radiological image analysis. CONCLUSIONS: In conclusion, compared with digital splints, artificial intelligent splints could save time for preoperative design while ensuring accuracy. The authors believed that it is conducive to the presurgical design of orthognathic surgery.

Intraoperative condylar positioning techniques on mandible in orthognathic surgery.

PURPOSE: The surgical condylar displacement often resulted in relapse and serious symptoms of temporomandibular joint disorders (TMD) after orthognathic surgery. To minimize the displacement, numerous techniques have been proposed. To verify their accuracy in positioning and effectiveness in preventing post-operative TMD and relapse, we reviewed the literature related to intraoperative condylar positioning techniques on the mandible in this study. METHODS: The literature on condylar positioning techniques was reviewed with two charts, including the non-computer-assisted and the computer-assisted positioning methods. The pre- and post-operative alterations of condyles, the post-operative temporomandibular joint (TMJ) function and surgical relapse were analysed regarding the techniques. The clinical usage and characteristics were reviewed as well. RESULTS: A total of 22 articles, including 907 patients, have been reported since 2001. Nearly all methods reach a considerable positioning accuracy within the range of 1-2 mm and 1-2° from the pre-operative position. We ranked the accuracy of the methods from high to low: CAD/CAM CPDs > CAD/CAM titanium plate positioning > manual positioning > computer-assisted navigation systems > imaging positioning systems. Most skeletal class II and class III patients achieved great occlusion and had no TMJ dysfunction or relapse after condylar positioning. CONCLUSIONS: Both the non-computer-assisted and computer-assisted condylar positioning techniques reach considerable accuracy in locating the pre-operative condyle position and preventing TMJ dysfunction and surgical relapse. Different levels of surgeons and cases can benefit from multiple suggested positioning methods. Further research with large samples and long-term follow-up is worth looking forward to upgrading the current methods, improving the clinical utility and developing new positioning techniques.

The Drilling Guiding Templates and Pre-Bent Titanium Plates Improves the Operation Accuracy of Orthognathic Surgery With Computer-Aided Design and Computer-Aided Manufacturing Occlusal Splints for Patients With Facial Asymmetry.

Facial asymmetry is a common maxillofacial deformity which requires surgery to recover the 3-dimensional relationship of bones. The computer-aided design and computer-aided manufacturing (CAD/CAM) has been developed and applied to improve orthognathic analysis and surgery design. How to accurately realize the preoperative design of orthognathic surgery with CAD/CAM occlusal splints during operation remains a big problem. In this study, 24 consecutive patients with facial asymmetry were recruited and assigned to 2 groups. For Group A, CAD/CAM was applied to designing and producing not only the occlusal splints, but also the drilling guiding templates and pre-bent titanium plates, and for Group B CAD/CAM was applied for occlusal splints only. Postoperative clinical examinations, symmetry evaluation through 3D cephalometric analysis, accuracy comparison using color distance maps and quantitative accuracy analysis were performed. Symmetry evaluation showed that patients of both groups achieved improved facial symmetry after surgery. The color distance maps and quantitative accuracy analysis together demonstrated significantly less difference found between virtual simulated surgery and postoperative CT scan data in Group A than in Group B. In conclusion, by navigation with the drilling guiding templates and pre-bent titanium plates, the facial symmetry for patients with facial asymmetry was successfully restored after orthognathic surgery, same as applying CAD/CAM occlusal splints only. However, the drilling guiding templates and pre-bent titanium plates would provide a more accurate performance according to preoperative simulation, especially for proximal mandibular segments.

Computer-Aided Design and Computer-Aided Manufacturing Cutting Guides in Eminoplasty for the Treatment of Temporomandibular Joint Dislocation.

OBJECTIVE: Temporomandibular joint (TMJ) dislocation means the condyle moves out of the normal position. There are several treatments for TMJ dislocation, including conservative treatment, injection treatment, minimally invasive treatment, and open surgical treatment. In this study, we tried to review the literature related to the augmentation of the articular eminence and proposed a modified eminoplasty technique of TMJ dislocation by computer-aided design and computer-aided manufacturing (CAD/CAM) cutting guides. METHODS: The literature on eminoplasty for TMJ was reviewed with 3 charts. Besides, 2 (67 and 69 years old) patients with chronic recurrent dislocation were treated by the CAD/CAM-guided surgical technique in our study, and postoperative measures were recorded to verify the safety and effectiveness regarding this technique. RESULTS: A total of 28 studies (including 268 patients) of the augmentation of the articular eminence have been reported since 1967, including the 2 present patients. According to the analysis of the recurrence and complications in the review, we found the modified technique had an obvious advantage. The technique with cutting guides was also found having higher accuracy. CONCLUSION: The modified technique was a reliable method when treating the TMJ dislocation, and the combination of CAD/CAM cutting guides was useful for more accuracy, even reduced the operation difficulty.

Computer-Aided Design and Manufacturing Cutting and Drilling Guides with Prebent Titanium Plates Improve Surgical Accuracy of Skeletal Class III Malocclusion.

BACKGROUND: The aim of this study was to evaluate the effects of the use of computer-aided design and manufacturing cutting and drilling guides with prebent titanium plates for the correction of skeletal class III malocclusion. METHODS: In this prospective, randomized, controlled clinical trial, 46 patients with skeletal class III malocclusion were randomly assigned into two groups. The patients underwent bimaxillary surgery with computer-aided design and manufacturing cutting and drilling guides with prebent titanium plates (experimental group) or computer-aided design and manufacturing splints (control group). Preoperative and postoperative imaging data were collected and then analyzed using Mimics Research 19.0, Geomagic Studio, and IBM SPSS Version 21.0. RESULTS: Deformity evaluation and posttreatment assessment were performed for all patients. The experimental group had fewer postoperative complications. Comparison of the linear and angular differences to facial reference planes revealed more accurate repositioning of the mandible and condyles in the experimental group, although the position of several landmarks still requires small adjustments. CONCLUSION: Computer-aided design and manufacturing cutting and drilling guides with prebent titanium plates effectively corrected skeletal class III malocclusion, providing positional control of segments with reasonable surgical accuracy. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, II.

Management of condylar resorption before or after orthognathic surgery: A systematic review.

BACKGROUND: Orthognathic surgery is a surgical procedure for the correction of maxillofacial deformities. The existence of condylar resorption before orthognathic surgery affects the selection of surgery time and plan. Besides, condylar resorption after orthognathic surgery often leads to the recurrence of deformities and affects the long-term effect of surgery. The purpose of this study was to perform a systematic review of the management of condylar resorption before or after orthognathic surgery. METHODS: A systematic review of the scientific literature listed on PubMed, Embase, and Cochrane Controlled Trials Register was performed, up to October 2018. The outcome of the search was reviewed with a chart. RESULTS: Ten articles with 180 patients were included in this study based on inclusion and exclusion criteria. We compared these studies to examine the effectiveness of the management of condylar resorption. CONCLUSION: The occurrence of condylar resorption can be influenced by complex factors. The management of condylar resorption before or after orthognathic surgery should base on the severity of condylar resorption. As the eligible studies with small sample sizes, heterogeneity in management method and outcome, high-quality clinical study concerning condylar resorption treatment is needed.

Robotic surgical systems in maxillofacial surgery: a review.

Throughout the twenty-first century, robotic surgery has been used in multiple oral surgical procedures for the treatment of head and neck tumors and non-malignant diseases. With the assistance of robotic surgical systems, maxillofacial surgery is performed with less blood loss, fewer complications, shorter hospitalization and better cosmetic results than standard open surgery. However, the application of robotic surgery techniques to the treatment of head and neck diseases remains in an experimental stage, and the long-lasting effects on surgical morbidity, oncologic control and quality of life are yet to be established. More well-designed studies are needed before this approach can be recommended as a standard treatment paradigm. Nonetheless, robotic surgical systems will inevitably be extended to maxillofacial surgery. This article reviews the current clinical applications of robotic surgery in the head and neck region and highlights the benefits and limitations of current robotic surgical systems.