Can Fracture Reduction be Attempted Through a 3D-Printed Guide Template Without Maxillomandibular Fixation?

Abstract

Background: Computer-aided design and manufacturing (CAD/CAM) is widely used in clinical practice. This technology may change existing methods for mandibular fracture management.Purpose: The purpose of this in-vitro study was to determine if the reduction for mandibular symphysis fracture can be performed without maxillomandibular fixation (MMF) using 3-dimensional (3D)-printed template.Study design, setting, and sample: This in-vitro study was designed as a proof-of-concept. The sample was composed of 20 existing pairs of intraoral scan and computed tomography (CT) data. A mandibular model stereolithography (STL) file was created by merging the STL file obtained for the bimaxillary denti-tions with the CT DICOM file, and this was set as the original model. Using the original model, a STL file of a fracture model of the mandibular symphysis was created using CAD. A template similar to a wafer or an implant guide was manufactured to restore original occlusion, and the mandibular fracture model was reduced and fixed using the 3D-printed template and wire. This was set as the experimental group. The 3D coordinate system error was measured at 6 landmarks and statistically compared using scan data be-tween models of the groups. Predictor/exposure/independent variables: Reduction techniques with MMF or without MMF using guide template for mandibular fracture model.Main outcome variable(s): The 3D coordinate system error (mm). Covariates: The position of landmarks.Analyses: The Mann-Whitney U test, student's t -test, and the Kruskal-Wallis test were used to analyze the coordinate errors between the landmarks. A P value of < .05 was considered statistically significant. Results: The 3D error value of the control and experimental group were 1.06  0.63 mm (range: 0.11 to 2.92 mm) and 0.96  0.48 mm (range: 0.2 to 2.95 mm), respectively. There was no statistical difference between the control and experimental group. There was a statistically significant difference in the lower 2 and lower 3 landmarks compared to the upper 1 (P = .001 and .000, respectively) before and after the reduction in the experimental group.Conclusion and Relevance: This study demonstrates that the reduction using a 3D-printed guide template for the mandibular symphysis fracture could be possible even without the MMF.& COPY; 2023 American Association of Oral and Maxillofacial Surgeons J Oral Maxillofac Surg 81:1025-1032, 2023