Is the masticatory function changed in patients with temporomandibular disorder?

Area of Science:

• Oral and Maxillofacial Surgery
• Neurology
• Biomechanics

Background:

• Temporomandibular disorders (TMD) are associated with masticatory dysfunction.
• Understanding the biomechanical and neurological factors influencing chewing in TMD patients is crucial.

Purpose of the Study:

• To analyze masticatory function in TMD patients using surface electromyography (EMG) and masticatory efficiency (ME).
• To compare chewing patterns and efficiency between TMD patients and a healthy control group.

Main Methods:

• Surface EMG of masseter and anterior temporal muscles during gum chewing.
• Clinical evaluation of habitual chewing (number of strokes, time) using a stuffed cookie.
• Masticatory efficiency (ME) assessment using fuchsin beads.
• Comparison between 27 TMD patients and 25 controls using Mann-Whitney statistical analysis.

Main Results:

• TMD patients demonstrated significantly higher ME (p<0.0001), more chewing strokes (p=0.04), and longer chewing time (p=0.009) compared to controls.
• Significant differences in EMG activity were observed in the masseter (right p=0.05, left p=0.005) and anterior temporal muscles (right p=0.05, left p=0.001) in the TMD group.
• Despite altered patterns, overall masticatory function was not impaired.

Conclusions:

• Patients with TMD exhibit a modified chewing pattern characterized by increased muscle activity and prolonged chewing duration.
• These alterations in chewing mechanics do not translate to a deficit in masticatory function or efficiency.