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

Abstract

The purpose of this study was to develop and validate a new chin template system for a two-piece narrowing genioplasty. Nine patients with wide chin deformities were enrolled. Surgeries were planned with the computer-aided surgical simulation (CASS) planning method. Surgical splints and chin templates were designed in a computer and fabricated using a three-dimensional printing technique. The chin template system included a cutting guide and a repositioning guide for a two-piece narrowing genioplasty. These guides were also designed to avoid the mental foramen area and inferior alveolar nerve loops during the osteotomy, for nerve protection. After surgery, the outcome evaluation was completed by first superimposing the postoperative computed tomography model onto the planned model, and then measuring the differences between the planned and actual outcomes. All surgeries were completed successfully using the chin template system. No inferior alveolar nerve damage was seen in this study. With the use of the chin templates, the largest linear root mean square deviation (RMSD) between the planned and the postoperative chin segments was 0.7 mm and the largest angular RMSD was 4.5°. The results showed that the chin template system provides a reliable method of transfer for two-piece osseous narrowing genioplasty planning.

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

“…The lower portion was designed to fit the surface of the osteotomized Le Fort I segment at its final position using the same six screw holes that had also previously been used for the cutting guide. Therefore, this combination of the pre-drilled screws and the custom plate would automatically bring the osteotomized Le Fort I segment to its final planned position 7,8 . In addition to the 11 repositioning screw holes, extra screw holes were also added to the plate in case they were needed to further stabilize the plate intraoperatively.…”

“…With the aim of eliminating the above-mentioned problem, a number of methods have been reported for independently repositioning the maxillary bony segment 4–8 . However, a disadvantage is that the placement and removal of the drilling and repositioning templates may further complicate the surgical procedure and increase the operating time.…”

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

“…Theses 3D printed-guides can be used for the osteotomy of the chin (AKA cutting guide) (13,15,20) or for the repositioning of the chin in its desired position after the osteotomy (AKA repositioning guide) (10,14). Some authors used these two type of guides (5,11,12,16,(16)(17)(18)(19)(21)(22)(23). With Lim et al (24), one guide is used simultaneous for guiding the cut and then repositioning of the chin.…”

“…Guides are stabilized by the external osseous relief of the mandible, or osteosynthesis screws, the occlusion, or by association of these (Table 2). Two main designs of a genioplasty surgical cutting or repositioning guide brings out these articles: one design of the guide uses the bony variations of the external chin area for the positioning of the guide (17,19,22) ; one other design uses the teeth for positioning of the guide (5,(10)(11)(12)14,21,23). Half of the authors combine the use of osteosynthesis screws with those techniques for fixing the guide (5,11,13,16,16,18,20,21,24).…”

“…The osteotomy location and the movement of the bony segment directly impacts the surgical outcome. Traditionally, genioplasty is performed based on surgeon's intraoperative assessment (5). In these present times, there is a surge of 3D printing technology in surgical techniques especially in the area of maxillo-facial surgery.…”