Tension headaches are those thought to be triggered by prolonged muscle contraction in the neck, jaw and head. This can be voluntary and subconscious (nervous or habitual), or involuntary in response to stressful situations.
Oftentimes when I take a history from a patient complaining of frequent tension headaches, I discover that the patient also has jaw pain. This could be a sign that the patient is grinding his/her teeth either during sleep or throughout the day. Worn down tooth surfaces in the molars are also a sign of grinding teeth.
When one grinds or clenches the jaw, two bilateral (both sides of the head) muscle groups are engaged: the masseter, which is the thick muscle you can palpate right over the angle of the jaw; and the temporalis, which anchors to the side of the head and attaches to the mandibular notch. These two muscles elevate the mandible (lower jaw).
When a muscle is under tension (also referred to as hypertonic or hyperactive) it is basically malfunctioning. Muscles control joint movement, and if the muscle is not working properly it can activate tiny nerves called mechanoreceptors and nociceptors embedded around the joint, causing pain.
When the temporalis muscle is under tension, it can affect blood flow around the scalp, which can also develop into a headache.
So, what can one do? Here’s a simple remedy that has anecdotal evidence to support it: open your jaw and relax it. To make it easier, insert a pencil or pen in between your teeth (but don’t bite down on it!) and hold it in place for a few minutes. This action inactivates the masseter and temporails muscles somewhat by activating their agonist pair, the pterygoid muscles.
Give it a try next time you feel a tension headache coming on. But better yet, focus on eliminating the environmental or emotional triggers that cause you to clench your teeth or tense up your neck and head muscles.