Yiting Sun

Three-dimensional printed final occlusal splint for orthognathic surgery: design and validation

Orthognathic surgery is indicated for the treatment of significant skeletal malocclusion and is normally prepared using conventional face bows combined with two-dimensional cephalometric analysis and manually made splints. With recent developments in oral imaging, more orthognathic surgeries are being planned using three-dimensional computer-aided design and manufacturing (3D CAD/CAM) software. The purpose of this study was to present a protocol for the design and 3D printing of final digital occlusal splints based on 3D planning of orthognathic surgery and to validate the accuracy of these splints. The 3D virtual planning was performed in PROPLAN software (Materialise). The required data were then exported into 3-matic software (Materialise) to design the splints, which were 3D printed in biocompatible material using an Objet Connex 350 printer (Stratasys). To validate the accuracy of the splints, the cases of 20 patients undergoing orthognathic surgery were analysed. The splints were assessed clinically and quantitatively by comparing the printed splints to the conventional analogue set-up (clinical standard) and recording the absolute distance errors of three landmarks. The mean absolute distance error was 0.4mm (standard deviation 0.17mm), which falls within clinically accepted error margins. The absolute distance error ranged from 0.12 to 0.88mm.

Validation of cone beam computed tomography–based tooth printing using different three-dimensional printing technologies

OBJECTIVE Our aim was to determine the accuracy of 3-dimensional reconstructed models of teeth compared with the natural teeth by using 4 different 3-dimensional printers. STUDY DESIGN This in vitro study was carried out using 2 intact, dry adult human mandibles, which were scanned with cone beam computed tomography. Premolars were selected for this study. Dimensional differences between natural teeth and the printed models were evaluated directly by using volumetric differences and indirectly through optical scanning. Analysis of variance, Pearson correlation, and Bland Altman plots were applied for statistical analysis. RESULTS Volumetric measurements from natural teeth and fabricated models, either by the direct method (the Archimedes principle) or by the indirect method (optical scanning), showed no statistical differences. The mean volume difference ranged between 3.1 mm(3) (0.7%) and 4.4 mm(3) (1.9%) for the direct measurement, and between -1.3 mm(3) (-0.6%) and 11.9 mm(3) (+5.9%) for the optical scan. A surface part comparison analysis showed that 90% of the values revealed a distance deviation within the interval 0 to 0.25 mm. CONCLUSIONS Current results showed a high accuracy of all printed models of teeth compared with natural teeth. This outcome opens perspectives for clinical use of cost-effective 3-dimensional printed teeth for surgical procedures, such as tooth autotransplantation.

A review of computer-aided oral and maxillofacial surgery: planning, simulation and navigation.

ABSTRACT Introduction: Currently, oral and maxillofacial surgery (OMFS) still poses a significant challenge for surgeons due to the anatomic complexity and limited field of view of the oral cavity. With the great development of computer technologies, he computer-aided surgery has been widely used for minimizing the risks and improving the precision of surgery. Areas covered: The major goal of this paper is to provide a comprehensive reference source of current and future development of computer-aided OMFS including surgical planning, simulation and navigation for relevant researchers. Expert commentary: Compared with the traditional OMFS, computer-aided OMFS overcomes the disadvantage that the treatment on the region of anatomically complex maxillofacial depends almost exclusively on the experience of the surgeon.

Computer-aided design and three-dimensional printing in the manufacturing of an ocular prosthesis

Restoring the facial appearance in acquired anophthalmos entails precision fitting of a customised ocular prosthesis. The fabrication is an artisanal process, and is primarily based on an impression of the anophthalmic cavity. This is usually achieved by the impression-moulding method, which, however, may introduce errors, resulting in a poorly fitted prosthesis. We developed a new method in the manufacturing of a customised ocular prosthesis based on computer-aided design and computer-aided manufacturing. An ocular prosthesis, based on a three-dimensional (3D) printed impression-free mould of the anophthalmic cavity, was successfully fitted in a 68-year-old male. To the best of our knowledge, this is the first case of a customised ocular prosthesis designed with the aid of 3D printing. Trial registration number B322201628407, Pre-results.

Computer-aided design and manufacturing of surgical templates and their clinical applications: a review

ABSTRACT Introduction: The surgical template is a guide aimed at directing the implant placement, tumor resection, osteotomy and bone repositioning. Using it, preoperative planning can be transferred to the actual surgical site, and the precision, safety and reliability of the surgery can be improved. However, the actual workflow of the surgical template design and manufacturing is quite complicated before the final clinical application. Areas covered: The major goal of the paper is to provide a comprehensive reference source of the current and future development of the template design and manufacturing for relevant researchers. Expert commentary: This paper aims to present a review of the necessary procedures in the template-guided surgery including the image processing, 3D visualization, preoperative planning, surgical guide design and manufacturing. In addition, the template-guided clinical applications for various kinds of surgeries are reviewed, and it demonstrated that the precision of the surgery has been improved compared with the non-guided operations.

Development of preoperative planning software for transforaminal endoscopic surgery and the guidance for clinical applications

PurposePreoperative planning is of great importance for transforaminal endoscopic techniques applied in percutaneous endoscopic lumbar discectomy. In this study, a modular preoperative planning software for transforaminal endoscopic surgery was developed and demonstrated.MethodsThe path searching method is based on collision detection, and the oriented bounding box was constructed for the anatomical models. Then, image reformatting algorithms were developed for multiplanar reconstruction which provides detailed anatomical information surrounding the virtual planned path. Finally, multithread technique was implemented to realize the steady-state condition of the software.ResultsA preoperative planning software for transforaminal endoscopic surgery (TE-Guider) was developed; seven cases of patients with symptomatic lumbar disc herniations were planned preoperatively using TE-Guider. The distances to the midlines and the direction of the optimal paths were exported, and each result was in line with the empirical value.ConclusionsTE-Guider provides an efficient and cost-effective way to search the ideal path and entry point for the puncture. However, more clinical cases will be conducted to demonstrate its feasibility and reliability.

Development of a computer-aided design software for dental splint in orthognathic surgery.

In the orthognathic surgery, dental splints are important and necessary to help the surgeon reposition the maxilla or mandible. However, the traditional methods of manual design of dental splints are difficult and time-consuming. The research on computer-aided design software for dental splints is rarely reported. Our purpose is to develop a novel special software named EasySplint to design the dental splints conveniently and efficiently. The design can be divided into two steps, which are the generation of initial splint base and the Boolean operation between it and the maxilla-mandibular model. The initial splint base is formed by ruled surfaces reconstructed using the manually picked points. Then, a method to accomplish Boolean operation based on the distance filed of two meshes is proposed. The interference elimination can be conducted on the basis of marching cubes algorithm and Boolean operation. The accuracy of the dental splint can be guaranteed since the original mesh is utilized to form the result surface. Using EasySplint, the dental splints can be designed in about 10 minutes and saved as a stereo lithography (STL) file for 3D printing in clinical applications. Three phantom experiments were conducted and the efficiency of our method was demonstrated.

Driedimensionaal printen voor orale en maxillofaciale toepassingen

Door de opkomst van driedimensionale beeldvorming is het mogelijk om beelden niet alleen te gebruiken voor hun diagnostische waarde, maar kan er ook een virtuele planning van de chirurgische ingrepen gemaakt worden. Naast het bestuderen van de chirurgische noden met behulp van softwareprogramma’s voor 3D-planningen en het inschatten van mogelijke complicatierisico’s kunnen er ook eventuele hulpmiddelen geprint worden die de chirurg kunnen helpen tijdens de operatie. De mogelijkheid om driedimensionaal te printen zorgt voor een grote sprong voorwaarts in orale en maxillofaciale toepassingen.