Muscle knots in the Deep Layer of the Masseter muscle are found low down near the angle of your jawbone, towards the back of your cheek, and are often easy to feel when you clench your teeth. When irritated, these specific muscle knots cause a sharp, localized tender pain right at the jawline, sometimes referring a deep ache into the ear or the area behind the cheekbone. This tension typically makes the jaw feel sore and tight, limiting motion and making powerful chewing feel uncomfortable.