A comparison of ultrasonic thickness of masseter muscle between patients with bruxism and healthy people

BACKGROUND AND OBJECTIVE: Evaluating the thickness of the masseter muscle is an important determinant of the health or illness of the muscle. Investigating changes in masseter muscle thickness due to its function on the temporomandibular joint plays a significant role in detecting the cause of many disorders in this joint. The present study aims to compare the ultrasonic thickness of masseter muscle between patients with bruxism and healthy people. METHODS: This case-control study was conducted among 44 subjects in two groups (22 subjects in each group of, including 11 women and 11 men) in the age range of 18 – 30 years old in patients with bruxism and healthy people. The subjects had normal BMI, had no inflammatory disease or strike to the temporomandibular joint, and had no history of maxillofacial surgery. Ultrasound evaluation of masseter muscle was performed in a supine position, with 12 MHz linear probe along the auricle and perpendicular to mandibular ramus on muscle ventricle and the thickness of the muscle was obtained in millimeters. FINDINGS: The masseter muscle thickness was more in patients with bruxism (11.97±0.85 mm) than healthy subjects (10.76±2.2 mm) (p<0.01). The masseter muscle thickness in men (12.54±0.4 mm and 11.44±0.25 mm, respectively) was more than that of women (11.4±0.79 mm and 10.08±3.05 mm, respectively) (p=0.038). CONCLUSION: The results of this study showed that the masseter muscle thickness in people with bruxism is more than healthy people and is more in men.