ELECTROPHYSIOLOGICAL CORRELATES OF MASTICATORY MUSCLES IN NASAL AND ORONASAL BREATHING MODES

Area of Science:

• Biomedical Engineering
• Orthodontics
• Physiology

Background:

• Masticatory muscle function is crucial for oral health and orthodontic status.
• Breathing modes can influence neuromuscular activity.
• Electromyographic (EMG) assessment provides insights into muscle function.

Purpose of the Study:

• To evaluate the electrophysiologic characteristics of masticatory muscles (temporalis and masseter) during nasal and oronasal breathing.
• To investigate potential correlations between breathing patterns, muscle activity, and orthodontic dysfunction.

Main Methods:

• Electromyography (EMG) was used to record electrical activity in the right and left temporalis and masseter muscles of 30 female volunteers.
• Maximal voluntary contraction (MVC) was standardized to assess muscle contractility.
• Participants were assessed in both nasal and oronasal breathing modes.

Main Results:

• Nasal breathing demonstrated homogenous and symmetric EMG activity in masticatory muscles.
• Oronasal breathing resulted in asymmetrical muscle activity, with more pronounced electrical activity in temporalis muscles.
• Electrophysiologic activity and contractility were reduced in oronasal breathers compared to nasal breathers.

Conclusions:

• Oronasal breathing leads to altered masticatory muscle electrophysiology, characterized by asymmetry and reduced contractility.
• These findings suggest that neuromuscular imbalance, influenced by breathing mode, is significant in assessing orthodontic status.
• EMG indicators show potential for estimating orthodontic dysfunction and guiding individualized treatment plans.