Infrared thermographic analysis of craniofacial muscles in military pilots affected by bruxism

INTRODUCTION: Due to the physical stresses to which they are subjected, military pilots may experience bruxism, an "oral parafunction." Parafunction can cause masticatory muscle suffering and serious dental, periodontal, and temporomandibular joint damage. The aim of this pilot study was to analyze the temperature distribution in masticatory and upper trapezius muscles in a sample of bruxist air force pilots, to evaluate whether an occlusal splint would be able to induce skin temperature variations in the stomatognathic apparatus using the technology of infrared thermography. METHODS: A total of 11 male Italian Air Force pilots of high performance aircraft, ages from 27 to 40 yr (mean 34.91 ± 2.15 yr) with 1000-3000 flight hours, were enrolled in the study and analyzed using an infrared camera in order to evaluate the temperature of the masticatory muscles. All the recordings were taken on each subject using the same protocol with and without a temporary occlusal splint. RESULTS: The occlusal splint statistically increased each muscle temperature (0.10-0.20°C) on both the sides of the body. No statistically significant differences were found between the left and right muscles (asymmetries) before or after the wearing of the splint except for the anterior temporalis muscle. No significant improvement or variations in temperature symmetry of this muscle was found after the application of the splint. DISCUSSION: The use of an occlusal splint could help in increasing muscles temperatures in Air Force pilots with consequent relaxation of their facial muscular system.