Psychophysiological definitions of clenching

Area of Science:

• Biomedical Engineering
• Neuroscience
• Dental Research

Background:

• Temporomandibular disorder (TMD) is associated with various oral behaviors, including clenching.
• Previous research has yielded inconsistent findings regarding the role of parafunctions in TMD etiology.
• Individual variability in muscle activity may contribute to these discrepancies.

Purpose of the Study:

• To investigate the variability of electromyography (EMG) activity in masticatory muscles during self-defined clenching tasks.
• To compare EMG variability during clenching versus minimal or maximal tooth contact.
• To explore the impact of individual differences in clenching behavior on TMD research.

Main Methods:

• Twenty participants without TMD pain underwent a biofeedback-training session to establish a relaxed baseline.
• Participants were instructed to clench their teeth based on their personal definition of the action.
• EMG data from masticatory muscles were collected during clenching, minimal contact, and maximal contact tasks.

Main Results:

• Individual subjects demonstrated high consistency in their personal definition and execution of clenching.
• The group as a whole exhibited substantial variability in EMG activity during clenching.
• Markedly greater variability was observed during clenching compared to minimal or maximal tooth contact.

Conclusions:

• The behavioral definition of clenching varies significantly across individuals.
• This individual variability in clenching behavior is a critical factor to consider in TMD research.
• Accounting for individual differences may help resolve discrepancies in understanding the role of parafunctions in TMD.