Does the use of protective face masks affect temporomandibular joint function?

Objective: Long-term mask use can trigger or exacerbate various health issues. This prospective experimental study evaluated the impact of protective face masks on masseter muscle activity and temporomandibular joint (TMJ) function reported by participants. Methods: This prospective, experimental tudy was conducted to investigate the effect of face masks on TMJ function, we used surface electromyography to assess masseter muscle activity at rest, during maximum contraction of the masseter muscle, and while reading a text. We also evaluated the intensity of the masseter muscle pain using an algometer. The participants underwent these evaluations at the Istanbul Medipol University between July and October 2022. Results: The study included 24 female participants with an average age of 28.5±5.40 years. After at least five hours of daily N95 mask use, a significant increase in masseter muscle activity was observed at rest and during speech (p=0.01; p=0.04, respectively). However, no significant changes in the maximum contraction of masseter muscle or pain threshold were observed (p>0.05). Conclusion: This study found that the use of N95 mask is associated with restricted TMJ movements and discomfort, and an increase in its use is associated with restricted TMJ movements, discomfort, and increased masseter muscle activity. Questions regarding mask-wearing-related habits should be included in the routine lifestyle assessment of patients who report TMJ complaints.