Why Does My Jaw Hurt When I Yawn? Causes and When to Worry

Why a Yawn Is the Movement That Hurts

Chewing opens your jaw a moderate amount. A full yawn opens it much further, and the joint has to slide forward in its socket to allow that. If the joint or the muscles around it are already irritated, that last stretch is where the pain appears.

The usual suspects are clenching or grinding, a jaw held tense at a desk or in traffic, a long dental appointment with your mouth open, or a bite that does not quite meet evenly. Most people find the cause is boring, and that it is the muscles rather than anything structural.

The Most Common Causes

• Clenching or grinding (bruxism), especially if the jaw is sorest in the morning. Our post on why the jaw hurts on waking covers that pattern.
• Muscle strain from a big bite, a long meal, or hours of tension, which usually settles within days.
• TMJ irritation, where the joint itself is inflamed. There may also be clicking, which we cover in why the jaw keeps popping.
• A tooth problem, such as an infected or cracked tooth, because pain travels along the jaw. We explain how in jaw pain from a tooth.
• Recent dental work, where the muscles stay sore after a long visit.

What You Can Do at Home First

• Yawn with your hand under your chin, which limits how far the jaw swings open.
• Eat soft food for a few days and skip anything that needs a wide bite.
• Use a warm compress on the sore side for a few minutes, a couple of times a day.
• Keep your teeth apart and lips together when you are not eating. Many people clench without noticing until someone points it out.
• Ibuprofen or paracetamol at the dose on the packet, if you can normally take them.

Do not force the jaw wide on purpose to see whether it still hurts. Everyone does it once, and it only irritates the joint further.

When It Is Worth Getting Checked

Come in sooner if you notice any of these:

• The jaw catches or locks, open or closed, even briefly.
• The pain has lasted more than two weeks without easing.
• One tooth is also sensitive or aching, or you can feel a swelling along the gum or cheek.
• Your bite feels different, with back teeth no longer meeting the way they did.
• The pain wakes you at night, or comes with earache or headaches on the same side.

If it turns out to be grinding, a night guard is the usual fix. If it is a tooth, treating the tooth settles the jaw. A cracked tooth can behave the same way, as described in cracked tooth and jaw pain.

Getting It Looked At in Beit Shemesh

At our clinic on Harav Kook in Beit Shemesh, we check how far the jaw opens and whether it deviates, feel the muscles, look for wear on the back teeth, and take an X-ray if a tooth could be involved. Dr. Joel treats in English and Hebrew, so you can describe exactly where and when it hurts rather than approximating. For a sore jaw that has changed, we can often offer a same-day appointment through our emergency dentist in Beit Shemesh service, and Ramat Beit Shemesh patients are only a couple of kilometres away.

If your jaw has locked wide open after a yawn, that is different. Read what happened when a jaw locked open on a yawn, and if it will not close at all, go to a hospital emergency department rather than waiting for a dental appointment.

When You Can Skip the Appointment

A slightly sore jaw for a day or two after a big meal or a long dental visit, which fades by itself and does not lock, does not need us. Rest it, keep it soft, and see how it is in a week. The American Dental Association's MouthHealthy page on TMJ and the NIDCR guide to TMJ disorders both describe this kind of short-lived soreness as common and usually self-limiting.

If it is not settling, or you are not sure which category you are in, send us a WhatsApp message and describe it. Urgent Dental Care, Harav Kook 28/1, Beit Shemesh, can tell you whether it is worth a visit. Related reading: a jaw that pops but does not hurt.