# A Thermal Imaging Camera as a Diagnostic Tool to Study the Effects of Occlusal Splints on the Elimination of Masticatory Muscle Tension

**Authors:** Danuta Lietz-Kijak, Adam Andrzej Garstka, Lidia Szczucka, Roman Ardan, Monika Brzózka-Garstka, Piotr Skomro, Camillo D’Arcangelo

PMC · DOI: 10.3390/dj13070313 · 2025-07-11

## TL;DR

This study uses thermal imaging to compare how two types of dental splints affect muscle tension in patients with jaw disorders.

## Contribution

The study demonstrates that occlusal splint design influences muscle relaxation and temperature changes in TMD patients.

## Key findings

- The double repositioning splint reduced muscle temperature by 0.8°C, indicating muscle relaxation.
- The Michigan splint increased muscle temperature by 0.7°C, suggesting less muscle relaxation.
- Splint type significantly affects temperature distribution and muscle tone in TMD patients.

## Abstract

Medical Infrared Thermography (MIT) is a safe, non-invasive technique for assessing temperature changes on the skin’s surface that may reflect pathological processes in the underlying tissues. In temporomandibular joint disorders (TMDs), which are often associated with reduced mobility and muscle overactivity, tissue metabolism and blood flow may be diminished, resulting in localized hypothermia. Aim: The purpose of this study was to evaluate muscle tone in the masseter, suprahyoid, and sternocleidomastoid muscles following the application of two types of occlusal splints, a Michigan splint and a double repositioning splint, based on temperature changes recorded using a Fluke Ti401 PRO thermal imaging camera. Materials and Methods: Sixty dental students diagnosed with TMDs were enrolled in this study. After applying the inclusion and exclusion criteria, participants were randomly assigned to one of two groups. Group M received a Michigan splint, while group D was treated with a double repositioning splint. Results: The type of occlusal splint influenced both temperature distribution and muscle tone. In the double repositioning splint group, temperature decreased by approximately 0.8 °C between T1 and T3, whereas in the Michigan splint group, temperature increased by approximately 0.7 °C over the same period. Conclusions: Occlusal splint design has a measurable impact on temperature distribution and muscle activity. The double repositioning splint appears to be more effective in promoting short-term muscle relaxation and may provide relief for patients experiencing muscular or myofascial TMD symptoms.

## Full-text entities

- **Diseases:** Muscle (MESH:D019042), hypothermia (MESH:D007035), TMDs (MESH:D013705), TMD (MESH:D049310)
- **Species:** Homo sapiens (human, species) [taxon 9606]

## Figures

9 figures with captions in the complete paper: https://tomesphere.com/paper/PMC12293494/full.md

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Source: https://tomesphere.com/paper/PMC12293494