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

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 dentitions 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 between 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.

Open versus closed treatment for extracapsular fracture of the mandibular condyle.

Objectives: Selection of treatment methods for mandibular condylar fractures remains controversial. In this study, we investigated treatment methods for condylar fractures to determine the indications for open or closed reduction. Patients and. Methods: Patients >12 years of age treated for mandibular condylar fractures with a follow-up period of ≥3 months were included in this study. The medical records of enrolled patients were reviewed for sex, age, fracture site, treatment method (open or closed reconstruction), postoperative intermaxillary fixation period, operation time, and complications. Radiological analysis of fracture fragment displacement and changes in ramal height difference was performed using computed tomography and panoramic radiography. Results: A total of 198 patients was investigated, 48.0% (n=95) of whom underwent closed reduction and 52.0% (n=103) underwent open reduction. There was no significant correlation between reduction method and patient sex, age, or follow-up period. No statistically significant difference between the incidence of complications and treatment method was observed. None of the patients underwent open reduction of condylar head fracture. Binary logistic regression analysis showed that open reduction was significantly more frequent in patients with subcondylar fracture compared to in those with a fracture in the condylar head area. There was no statistically significant correlation between the groups and fracture fragment displacement. However, there was a significant difference between the treatment groups in amount of change in ramal height difference between the fractured and the nonfractured sides during treatment. Conclusion: No significant clinical differences were found between the open and closed reduction methods in patients with mandibular condylar fractures. According to fracture site, closed reduction was preferred for condyle head fractures. There was no significant relationship between fracture fragment displacement and treatment method.