Masticatory electromyographic activity in response to simulated dental practices: influence of stress, mental workload, and bruxism

Abstract

Objective: To evaluate changes in surface electromyographic activity (sEMG) of the masseter and anterior temporalis muscles after performing simulated dental practices of different complexity, analyzing their relationship with stress, mental workload and bruxism.

Methods: This experimental, cross-sectional, repeated-measures study with a counterbalanced crossover design will be conducted with dental students. Following a pilot study with 8 subjects (for methodological adjustment and sample size calculation), two parallel groups will be formed: one with possible bruxism, determined by self-report, and another without bruxism. In a single session, participants will perform a simple and complex dental procedure on a haptic simulator (Simodont®). To control the learning effect, they will be randomly assigned to two execution sequences: half will begin with the simple task and the other half with the complex task, with an intermediate rest period to minimize potential fatigue effects. Bilateral wireless sEMG will be recorded using the Trigno system (Delsys®) before and immediately after each task, at rest and during maximal voluntary contraction (MVC). Stress will be assessed using a Visual Analog Scale, and mental workload with the NASA-TLX method. Muscle electrical activity data will be processed using linear mixed models in R (α=0.05).

Expected Results: To identify alterations in the neuromuscular behavior of students during simulated clinical practice, influenced by the complexity of the task and the presence of bruxism. The findings could contribute to understanding the immediate impact of stress and the mental demands of clinical practice on the operator´s masticatory system.