Three-Dimensionally Printed Patient-Specific Surgical Plates Increase Accuracy of Oncologic Head and Neck Reconstruction Versus Conventional Surgical Plates: A Comparative Study

Abstract

Background: Surgeons are pursuing accurate head and neck reconstruction to enhance aesthetic and functional outcomes after oncologic resection. This study aimed to investigate whether accuracy of head and neck reconstruction is improved with the use of three-dimensionally (3D)-printed patient-specific surgical plates compared with conventional plates.

Methods: In this comparative study, patients were prospectively recruited into the study group (3DJP16) with 3D-printed patient-specific surgical plates. The patients in control group with conventional surgical plates were from a historic cohort in the same unit. The primary end point of the study was the accuracy of head and neck reconstruction. The secondary end points were accuracy of osteotomy, intraoperative blood loss, total operative time, and length of hospital stay.

Results: The study recruited of 33 patients, including 17 in the study group and 16 in the control group. The patients' baseline characteristics were similar between the two groups. The absolute distance deviation of the maxilla or mandible was 1.5 ± 0.5 mm in the study group and 2.1 ± 0.7 mm in the control group [mean difference, - 0.7 mm; 95% confidence interval (CI) - 1.1 to - 0.3; p = 0.003], showing superior accuracy of reconstruction for the patients with 3D-printed patient-specific surgical plates. Improved accuracy of reconstruction also was detected in terms of bilateral mandibular angles and bone grafts. Concerning the secondary end points, the accuracy of the osteotomy was similar in the two groups. No difference was found regarding intraoperative blood loss, total operative time, or length of hospital stay.

Conclusions: This is the first study to prove that compared with conventional plates, 3D-printed patient-specific surgical plates improve the accuracy of oncologic head and neck reconstruction.

Trial registration: ClinicalTrials.gov NCT03057223.

Conflict of interest statement

All authors declare that they have no conflict of interest.

Figures

Fig. 1

Study flowchart and working principles of combining three-dimensionally (3D)-printed patient-specific surgical plates with computer-assisted surgery (CAS) in head and neck reconstruction. a In the study group, patient-specific surgical plates guided the accurate folding and fixing of bone segments. Screw holes embedded in cutting guides correspond to those in the 3D-printed patient-specific surgical plates. b In the control group, bone segments were manually manipulated and stabilized using commercial off-the-shelf plates, which should be bent and twisted

Fig. 2

Accuracy outcome parameters of head and neck reconstruction. a Absolute distance deviation of the mandible. The postoperative mandible is repositioned to coincide with the preoperative virtually reconstructed mandible based on the side not treated by surgery. The absolute distance deviation of the mandible is measured by calculating the distance between the pre- and postoperative mandibles based on points in which green indicates small deviations, and red indicates large deviations. b Distance and angulation deviations of condylar heads. The intercondylar line is created by connecting the most superior points of the bilateral condylar heads. The distance deviation is defined as the difference in length of the pre- and postoperative intercondylar lines, and the angulation deviation is the angle formed by the pre- and postoperative intercondylar lines. c Distance and angulation deviations of mandibular angles. The intergonial line is created by connecting the most posterior inferior points of the bilateral mandibular angles. The distance deviation is defined as the difference in length of the pre- and postoperative intergonial lines, and the angulation deviation is the angle formed by the pre- and postoperative intergonial lines. d Distance and angulation deviations of reconstructed bone segments. The center point and central axis of each bone graft are generated. The distance deviation of bone graft is defined as the distance between the pre- and postoperative center points, and the angulation deviation is the angle between the pre- and postoperative central axes of the bone grafts. e Distance and angulation deviations of the skull bone resection. f Distance and angulation deviations of the bone graft osteotomy. In measuring the accuracy of the skull bone resection or the bone graft osteotomy, each bone segment is registered separately from the corresponding preoperative entity. Initially, the osteotomy planes are delineated, and the center points of each osteotomy plane are located. Then the angle formed by the pre- and postoperative osteotomy planes is defined as the angulation deviation of the osteotomy, whereas the distance deviation of the osteotomy refers to the distance between the center points of the pre- and postoperative osteotomy planes

Fig. 3

Accuracy results of head and neck reconstruction. a Absolute distance deviation of maxilla or mandible. b Distance and angulation deviations of condylar heads. c Distance and angulation deviations of mandibular angles. d Distance and angulation deviations of reconstructed bone segments. In all plots, error bars depict means and standard deviations. All statistical comparisons are performed using the independent-samples t test. All p values lower than 0.007 are indicated with an asterisk (*)

Fig. 4

Accuracy of skull bone resection and bone graft osteotomy. a Distance and angulation deviations of skull bone resection. b Distance and angulation deviations of bone grafts osteotomy. In all plots, error bars depict means and standard deviations

Fig. 5

A 33-year-old woman with desmoplastic ameloblastoma in the anterior maxilla underwent surgery. a The preoperative computed tomography (CT) image indicates the destructive mass in the anterior maxilla. b A three-dimensional (3D) virtual model is used to delineate bone resection margins and design cutting guides. c The patient-specific surgical plate is designed to fix bone grafts. d The vascularized fibular flap is harvested, segmented, folded, and fixed in alignment with the patient-specific surgical plate. e The bone-plate complex is transferred to repair the defect site. f Postoperative OPG showing satisfactory bone healing. g Postoperative intraoral image showing healed alveolar ridge. h Dental implants placed in the transplanted fibula in the second stage. i Intraoral image showing the accurate position of implants as planned. j OPG showing satisfactory implant position and angulation. k Immediate loading of dental implants supports the removable partial denture in the anterior maxilla. Excellent occlusal relationship is achieved. l Satisfactory postoperative aesthetics