Clinical effectiveness of a patient-tailored mouthpiece based on 3-dimensional (3D) scanner modeling and 3D printing technology for microstomia caused by burns: A pilot study.

Abstract

Microstomia is defined as a small mouth size that interferes with daily activities. No protocol has been established for microstomia caused by facial burns. This study aimed to confirm the clinical usefulness of a patient-customized mouthpiece using 3D scanner modeling and printing technology. Each participant's mouth was scanned using a 3D scanner and the scanned model was imported into modeling software. After modeling the mouthpiece to fit the maximum horizontal and vertical lengths of the mouth and the thickness of the lips, it was manufactured using a 3D printer. The participants were monitored while wearing the mouthpiece for more than 12 h a day, including 8 h of sleep. As the primary outcome, the vertical and horizontal distances of the mouth were measured before and after wearing the customized mouthpiece for 2 months. As secondary outcomes, biological scar properties, Vancouver Scar Scale (VSS) scores, and Patient and Observer Scar Assessment Scale (POSAS) scores were evaluated. Five patients with burns on the upper, lower, left, and right sides of the mouth who underwent skin grafting were included in this study. The patients had contractures in all directions. Comparing measurements before and after 8 weeks of wearing the mouthpiece, the distances (horizontal and vertical) improved from 3.86 ± 0.56 mm and 2.16 ± 0.48 initially to 4.28 ± 0.38 and 2.82 ± 0.77 after wearing the mouthpiece (P = 0.20 and 0.04). Statistically significant improvements were observed in the pliability of the VSS (P = 0.04) and the thickness and overall opinion (P = 0.04) of the POSAS-observer component. In the comparison of biomechanical properties, improvements were observed in scar characteristics, although the differences were not statistically significant (P > 0.05). The application of a patient-tailored mouthpiece using 3D scanner modeling technology for microstomia caused by hypertrophic scars after burns has shown positive effects for improving size and oral function without causing side effects on the scars.