Increase in masseter muscle activity by newly fabricated complete dentures improved brain function.

Area of Science:

• Neuroscience
• Gerontology
• Biomedical Engineering

Background:

• Complete dentures can cause inconvenience for edentulous elderly individuals.
• Masseter muscle activity is crucial for chewing and may influence cognitive function.
• Understanding the link between oral function and brain health is important for aging populations.

Purpose of the Study:

• To investigate the effects of improved masseter muscle activity on brain function in elderly individuals with complete dentures.
• To assess whether newly fabricated dentures enhance masseter muscle activity and subsequent cognitive performance.
• To explore the relationship between enhanced chewing function and neural activity in the aging brain.

Main Methods:

• 14 edentulous elderly patients evaluated with old (OD) and newly fabricated dentures (ND).
• Surface electromyography (EMG) measured masseter muscle activity.
• Functional magnetic resonance imaging (fMRI) analyzed brain activity during a chewing task.
• Cognitive functions assessed using Trail Making Test Part A (TMT-A), RAVLT, and R-OCFT.

Main Results:

• Newly fabricated dentures significantly increased masseter muscle activity compared to old dentures (p < 0.05).
• Brain activity increased in multiple regions, including the superior frontal gyrus, precentral gyrus, and cerebellum, under the ND condition (p < 0.01).
• Cognitive test results (TMT-A, RAVLT, R-OCFT) significantly improved with newly fabricated dentures (p < 0.05).

Conclusions:

• Improved masseter muscle activity, facilitated by better-fitting dentures, enhances brain activity in edentulous elderly individuals.
• Enhanced neural activity correlates with improvements in attention, verbal skills, and visual memory.
• Optimizing oral function through improved dentures may be a viable strategy to support cognitive health in aging populations.