[Analysis of mastication in normal and dysfunctional subjects]

Area of Science:

• Biomedical Engineering
• Dental Science
• Neuromuscular Physiology

Background:

• Mastication involves complex coordination of mandibular movements and muscle activity.
• Temporomandibular joint (TMJ) disorders often impair chewing function.
• Objective assessment of masticatory performance is crucial for diagnosis and treatment.

Purpose of the Study:

• To evaluate mandibular movements and electromyographic (EMG) activity of masseter and temporal muscles during mastication.
• To compare chewing performance between healthy subjects and patients with TMJ dysfunction.
• To identify specific masticatory parameters associated with severe TMJ impairment and muscle dysfunction.

Main Methods:

• A computer-based system and Siemens Sirognathograph were used to record mandibular movements.
• Surface Ag/AgCl electrodes recorded EMG signals from masseter and temporal muscles.
• Chewing performance was assessed using a standardized crispy bread bolus in 12 healthy and 86 dysfunctional subjects.

Main Results:

• Statistically significant differences were observed in masticatory parameters between healthy individuals and the dysfunctional group.
• Subgroup analysis revealed distinct patterns of mandibular movement and muscle activity in patients with severe TMJ impairment versus severe muscle dysfunction.
• The computer-based system effectively differentiated chewing performance based on the severity of TMJ and muscle dysfunction.

Conclusions:

• Computer-aided analysis of mandibular movements and EMG provides objective insights into masticatory function.
• Masticatory performance is significantly altered in individuals with TMJ dysfunction.
• This system aids in differentiating and characterizing subtypes of TMJ-related chewing impairments.