Twenty healthy participants performed four sets of hundred-square calculations as a mental arithmetic task. During the assignment, they were instructed either to clench their teeth, or relax their jaw. (At the same time, the electrical activity of their left masseter muscle was recorded to confirm clenching.) Scores on the math(s) test showed that there was no effect of conscious clenching on simple arithmetic tasks in healthy participants. Allowing the research team to make a recommendation :
“…the results indicate that it may not be harmful for clinicians to encourage their patients to refrain from clenching their teeth.”
See: No effect of conscious clenching on simple arithmetic task in healthy participants. Journal of Prosthodontic Research, article in press.