Investigating the accuracy of mandibulectomy and reconstructive surgery using 3D customized implants and surgical guides in a rabbit model

Min Keun Kim; Min Ji Ham; Won Rae Kim; Hyung Giun Kim; Kwang Jun Kwon; Seong Gon Kim; Young Wook Park

doi:10.1186/s40902-023-00375-9

Investigating the accuracy of mandibulectomy and reconstructive surgery using 3D customized implants and surgical guides in a rabbit model

Maxillofac Plast Reconstr Surg. 2023 Jan 26;45(1):8. doi: 10.1186/s40902-023-00375-9.

Authors

Min Keun Kim¹, Min Ji Ham², Won Rae Kim², Hyung Giun Kim², Kwang Jun Kwon³, Seong Gon Kim³, Young Wook Park³

Affiliations

¹ Department of Oral and Maxillofacial Surgery, College of Dentistry, Gangneung-Wonju National University, Gangneung, 25457, Republic of Korea. omfsmk@gwnu.ac.kr.
² Functional Materials and Components R&D Group, Korea Institute of Industrial Technology, Gangneung, 25440, Republic of Korea.
³ Department of Oral and Maxillofacial Surgery, College of Dentistry, Gangneung-Wonju National University, Gangneung, 25457, Republic of Korea.

Abstract

Background: This study aimed to analyze the accuracy of the output of three-dimensional (3D) customized surgical guides and titanium implants in a rabbit model, and of mandibulectomy, reconstructive surgery, and surgical outcome; additionally, the correlation between surgical accuracy and surgical outcomes, including the differences in surgical outcome according to surgical accuracy, was analyzed.

Results: The output of implants was accurately implemented within the error range (- 0.03-0.03 mm), and the surgical accuracy varied depending on the measured area (range - 0.4-1.1 mm). Regarding surgical outcomes, angle between the mandibular lower borders showed the most sensitive results and distance between the lingual cusps of the first molars represented the most accurate outcomes. A significant correlation was noted between surgical accuracy in the anteroposterior length of the upper borders pre- and postoperatively and the angle between the mandibular lower borders (regression coefficient = 0.491, p = 0.028). In the group wherein surgery was performed more accurately, the angle between the mandibular lower borders was reproduced more accurately (p = 0.021). A selective laser melting machine accurately printed the implants as designed. Considering the positive correlation among surgical accuracy in the mandibular upper borders, angle between the mandibular lower borders, and more accurately reproduced angle between the mandibular lower borders, the angle between the mandibular lower borders is considered a good indicator for evaluating the outcomes of reconstructive surgery.

Conclusion: To reduce errors in surgical outcomes, it is necessary to devise a positioner for the surgical guide and design a 3D surgical guide to constantly maintain the direction of bone resection. A fixed area considering the concept of three-point fixation should be selected for stable positioning of the implant; in some cases, bilateral cortical bone fixation should be considered. The angle between the mandibular lower borders is a sensitive indicator for evaluating the outcomes of reconstructive surgery.

Keywords: 3D printing; Accuracy; Customized titanium implant; Rabbit model; Surgical guide.

Abstract

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