Reflex and cortical responses to dental stimuli

Area of Science:

• Neuroscience
• Dental Physiology

Background:

• Tooth pulp stimulation can trigger muscle reflexes, potentially contaminating brain activity measurements.
• Understanding these reflexes is crucial for accurately interpreting cortical evoked responses.

Purpose of the Study:

• To investigate the impact of repetitive tooth pulp stimulation on cortical evoked responses.
• To identify methods for minimizing muscle reflex interference in electrophysiological recordings.

Main Methods:

• Utilized repetitive tooth pulp stimulation to evoke responses.
• Monitored electromyography (EMG) signals from facial and neck muscles.
• Analyzed cortical evoked responses using electroencephalography (EEG) with a focus on specific electrode placements.

Main Results:

• Repetitive stimulation reduced the amplitude of cortical responses but largely avoided muscle reflexes.
• A silent period in the temporal muscle (jaw muscle) was observed, affecting early signal components (0-70 ms).
• A distinct negative deflection at 43 ms was detected in center-posterior EEG leads, suggesting a more reliable measure of cortical activity.

Conclusions:

• Repetitive stimulation is a viable technique to mitigate muscle reflex artifacts in tooth pulp evoked potentials.
• Early cortical responses can be reliably identified in specific EEG leads despite residual muscle artifacts.