Efficacy of a 3D-printed static progressive microstomia orthosis in increasing mouth opening and function following burn injury.

Abstract

Microstomia, often observed following facial burn injuries, can hinder functional activities such as eating, speaking, dental care, and medical procedures such as intubation. To address these challenges, microstomia orthoses (MO) are used to increase mouth opening and function. Many versions of MOs have been described from hand-crafted to commercially available models. However, proposed options can be quite expensive based on fabrication time or materials, and not all models can be customized for patient's needs. 3D printing presents a promising alternative for fabricating MOs, addressing many of the limitations of currently used methods. The purpose of this study was to develop and evaluate the efficacy of a 3D-printed static-progressive MO in increasing mouth opening and improving functional outcomes. The orthosis was used to treat six adult burn survivors with pre-post evaluation using the Mouth Impairment and Disability Assessment (MIDA). The cost-effectiveness of this 3D MO was also investigated. A customizable 3D-printed static-progressive MO was co-designed by clinicians and two burn survivors, which cost approximately $2-3 USD of materials to produce. The prescribed wearing regime of this 3D-printed static-progressive MO resulted in significant improvement of vertical and horizontal mouth opening and MIDA scores with treatment and time. These results were achieved with patients wearing the MO 2-3x/day for 10-15 min, followed by completing their therapeutic activities and mouth exercises after wearing the MO. The global accessibility, low cost, and relative efficiency of this orthosis will be invaluable, particularly in resource poor regions. All 3D-printable files for this 3D-printed MO are publicly available (Appendix 1).