What does electro-myography measure in the context of the masticatory muscles?

What does electro-myography measure in the context of the masticatory muscles?

• A. Movement of the jaw during chewing
• B. Muscular tonus during contraction
• C. Blood flow to masticatory muscles
• D. Bio-potential of the muscles during contraction

Answer: (D)

Electro-myography measures the electrical activity generated by muscle fibers when they contract. This bio-potential comes from motor units firing and reflects how many units are activated and how fast they fire, giving a direct readout of muscle activation levels. It doesn’t track jaw movement itself (that would be a motion reading) and it doesn’t measure blood flow to the muscle. It also isn’t a direct measure of resting muscle tone; it shows activation during contraction. In the masticatory system, EMG is used to analyze how the masseter and temporalis fire during chewing or clenching, assess coordination between sides, and detect patterns of hyperactivity or fatigue. Data can be collected with surface electrodes for superficial muscles or fine-wire electrodes for deeper muscles.

Electro-myography measures the electrical activity generated by muscle fibers when they contract. This bio-potential comes from motor units firing and reflects how many units are activated and how fast they fire, giving a direct readout of muscle activation levels. It doesn’t track jaw movement itself (that would be a motion reading) and it doesn’t measure blood flow to the muscle. It also isn’t a direct measure of resting muscle tone; it shows activation during contraction. In the masticatory system, EMG is used to analyze how the masseter and temporalis fire during chewing or clenching, assess coordination between sides, and detect patterns of hyperactivity or fatigue. Data can be collected with surface electrodes for superficial muscles or fine-wire electrodes for deeper muscles.