Why Does Jaw Hurt on One Side? A Dentist Explains the Common Causes

Most of the time, when your jaw hurts on one side, it's not the scary thing you're imagining. It's your jaw joint or the muscles around it, usually from grinding or clenching, you don't even know you're doing. The team at Appin Dental Surgery sees this every week, and the pattern is almost always the same: the pain shows up on one side, it's worse in the morning, or when you chew, and people have spent two nights on Google convincing themselves it's something terrible.

So let's sort out what's actually going on. This guide walks through why your jaw hurts on one side, what each cause feels like, what you can do at home tonight, and the point where it stops being a "wait and see" and becomes a "get it looked at."

The principal dentist at Appin Dental Surgery has treated patients across Queensland and New South Wales for over 19 years, and jaw pain is one of the most common things people downplay until they can't chew on one side anymore.

What Causes Jaw Pain on One Side?

The most common cause of one-sided jaw pain is a temporomandibular joint disorder, often shortened to TMD or TMJ (that's the hinge joint just in front of your ear that connects your lower jaw to your skull). You've got one on each side, and they don't always behave the same way, which is exactly why pain can land on the left or the right on its own.

But TMJ isn't the only culprit. Here are the six causes we see most often.

TMJ disorder

Your jaw joint is doing a lot of quiet work all day: talking, chewing, yawning, swallowing. When the joint, the disc inside it, or the muscles around it get strained or inflamed, you get pain that's often worse on one side. You might also notice clicking or popping when you open, a dull ache near your ear, or headaches around your temples.

This is more common than people think. An Australian national study of adults found that around 1 in 10 reported a temporomandibular disorder, and the figure climbs much higher when you count people with at least one symptom they've never had checked.

Teeth grinding and clenching (bruxism)

A huge share of the one-sided jaw pain we treat traces back to grinding or clenching, usually at night. The clinical name is bruxism. Most people have no idea they do it. They just wake up with a tight, sore jaw on one side, maybe a headache, and over time their teeth start looking flat or chipped.

Why one side? Because almost nobody grinds evenly. You favour a side, the muscles on that side work harder, and that's where the ache shows up. If you clench during the day at your desk, same deal.

A tooth problem

Sometimes the jaw isn't the problem at all. A deep cavity, a cracked tooth, or an abscess (a pocket of infection at the root) can send pain radiating straight into your jaw on that side. The giveaway: it usually gets sharper when you bite down or when something hot or cold hits the tooth.

An abscess is the one you don't sit on. If you've got swelling, a bad taste, a fever, or throbbing that's getting worse, that's an infection and it needs treating, not waiting out. We cover the warning signs in our guide on when you need antibiotics for a toothache.

Sinus trouble

Your upper back teeth sit right under your sinuses. When you've had a cold or your hayfever's flaring, those sinuses get inflamed and the pressure can feel exactly like jaw or tooth pain, usually on one side, usually in the upper jaw. The tell is that it tends to come with a stuffy nose and gets worse when you lean forward. Clears up when the sinus does.

Wisdom teeth

A wisdom tooth that's pushing through at an angle, or stuck under the gum, causes pain right at the back of the jaw on one side. It can ache, swell, and make it sore to open wide. This one turns up a lot in patients in their late teens and twenties, often the uni-aged crowd around exam season when they're stressed and grinding on top of it. If that's what's going on, our page on wisdom teeth removal and timing walks through when it's worth acting.

Injury or muscle strain

A knock to the face, a fall, biting down hard on something unexpected, or even a long dental appointment with your mouth open can strain the muscles or joint on one side. Posture plays a part too. Cradling your phone between your shoulder and ear, or always sleeping on the same side with your hand jammed under your jaw, loads one side more than the other.

Why Does Jaw Pain Land on the Left or Right Side?

Your jaw hurts on one side because you have two separate joints, and they wear, strain, and inflame independently. One joint can be perfectly happy while the other is not.

This is the bit most articles skip, and it's the question patients actually ask. Here's what usually decides which side:

• The side you chew on. Most people have a preferred chewing side without realising it. That side's muscles and joint do more work.

• The side you sleep on. Constant pressure on one jaw overnight adds up.

• The side you grind toward. Bruxism is rarely symmetrical.

• Where the dental problem is. A bad tooth or coming-through wisdom tooth pins the pain to its own side.

  
  

Left side, right side, the causes are the same list. The side just tells you where the strain or the problem is sitting. One thing worth knowing: jaw pain on the left can occasionally be linked to a heart problem, especially if it comes with chest tightness, shortness of breath, or sweating. That's rare, and the red flags below cover it in full, because it matters.

Why Does Jaw Pain Get Worse When Chewing or Opening Your Mouth?

If your jaw hurts when you chew or open wide, the joint or the muscles that move it are usually the source, not the teeth themselves. Chewing and opening load the temporomandibular joint directly, so an inflamed or strained joint complains the moment you ask it to work.

A few patterns point to the likely source. Pain plus a click or a catch when you open points toward the joint and its disc. A deep ache that builds while you eat and eases when you rest points toward tired, overworked muscles, classic clenching. Sharp pain on biting a specific spot points back at a tooth, often a crack.

If your jaw is locking, catching, or only opening partway, don't force it. That's a sign the joint needs a proper look rather than another week of soft food.

Why Does a Sore Jaw Show Up in the Morning?

Waking up with a sore jaw on one side is most often a sign of night-time grinding or clenching. While you sleep, you can't feel yourself doing it, so the first clue is the ache when you wake up, sometimes with a headache or teeth that feel tender.

Stress is the big driver, and it spikes at predictable times of year. Around exam season and the end of the financial year, more clenchers walk through the door at Appin Dental Surgery, jaw sore on one side, no idea they've been grinding through the night. Families across Wollondilly and the newer estates out at Wilton and Bingara Gorge are no different. Stress finds the jaw.

The good news is this one's very manageable once it's confirmed. A properly fitted night splint takes the pressure off the joint and protects your teeth from the wear grinding causes. More on that further down.

How Can You Relieve Jaw Pain on One Side at Home?

For mild, recent jaw pain on one side, you can often settle it at home in a few days. Here's what's worth trying first:

1. Rest the jaw. Soft foods for a few days. Cut food small. Skip the chewing gum, the tough steak, the crusty bread, and anything you have to wrench your mouth open for.

   
   

2. Heat or cold. A warm compress relaxes tight muscles; a cold pack calms a sharp, swollen joint. Fifteen minutes at a time. Use whichever gives you more relief.

   
   

3. Over-the-counter anti-inflammatories. Something like ibuprofen (if it's safe for you) can bring down both pain and inflammation. Follow the packet, and check with your pharmacist if you're on other medications.

   
   

4. Mind the clenching. Through the day, your teeth should only touch when you eat. Lips together, teeth slightly apart. Sounds tiny. Makes a real difference.

   
   

5. Gentle movement. Slow, small open-and-close and side-to-side movements keep the joint from stiffening. Gentle is the word. If it hurts sharply, stop.

   
   

Give it a few days. Most mild muscle-related jaw pain eases off with rest and the steps above. What home care won't fix is a cracked tooth, an abscess, or a joint that keeps locking. So if it's not budging, that's your signal.

When Should You See a Dentist About Jaw Pain?

See a dentist if your one-sided jaw pain lasts more than a week, keeps coming back, or gets worse instead of better. That's the simple rule. A week of steady or worsening pain has passed, something you should be managing alone.

Book sooner, not in a week, if you notice any of these:

• Swelling on one side of your face or jaw

• A fever, a bad taste, or pus (signs of infection)

• Your jaw locking, catching, or not opening properly

• Pain sharp enough to stop you eating or sleeping

• A tooth that's painful to bite on

  
  

And this one is not a dental issue, it's an emergency: jaw pain (more often on the left) that comes with chest pain or tightness, shortness of breath, nausea, or a cold sweat can be a sign of a heart attack. Call 000 straight away. Don't wait, and don't drive yourself.

For the dental causes, getting in early really changes how much treatment you need. A grinding habit caught now means a splint. Caught in two years, it can mean repairing worn or cracked teeth. An abscess seen today is far simpler than one that's spread.

How We Help With One-Sided Jaw Pain at Appin Dental

Most jaw pain that walks through our door comes down to one of two things: the joint and muscles (grinding, clenching, TMJ strain), or a tooth that's gone bad. The first step is always the same, working out which one you've got, because the treatment is completely different.

If it's grinding or clenching, a custom night splint is usually the answer. It's a slim, comfortable guard made to fit your bite that cushions the joint and stops your teeth wearing each other down. You can read how they work on our occlusal splints page, and it's the same approach we use for jaw-muscle tension and TMJ-related discomfort.

If the pain's coming from a tooth, an abscess, or a problem that flared up fast, that's where same-day care matters. Our emergency dental options cover exactly that kind of acute pain, and we keep room for urgent bookings.

We look after families right across Wollondilly, from Wilton and Picton through to Appin itself. As the only QIP-accredited dental practice in Wollondilly Shire, and building on the 30-plus year legacy of our sister practice, Bradbury Dental Surgery, we've seen just about every version of one-sided jaw pain there is.

Frequently Asked Questions

Can jaw pain on one side go away on its own? 

Yes, often. Mild jaw pain from muscle strain or a one-off knock usually settles within a few days to a couple of weeks with rest, soft food, and easing off the clenching. If it lasts longer than a week or keeps returning, it's worth getting checked, because that pattern points to something that won't fix itself.

Why does my jaw hurt on one side near my ear? 

The temporomandibular joint sits right in front of your ear, so when it's inflamed or strained, the pain lands near the ear on that side. It's one of the most common spots for TMJ-related pain. It can also bring on earaches or a feeling of fullness in the ear even when your ears are perfectly healthy.

Is one-sided jaw pain serious? 

Usually not. Most cases come from grinding, a tired jaw muscle, sinus pressure, or a tooth issue, all very treatable. The exceptions to take seriously are jaw pain with facial swelling and fever (a possible infection), or left-sided jaw pain with chest pain, breathlessness, or sweating, which needs emergency care.

Why does my jaw hurt when I wake up but feel fine later? 

That's a classic sign of night-time grinding or clenching. The jaw is at its sorest in the morning after a night of pressure, then loosens up through the day as the muscles recover. A custom night splint is the usual fix once a dentist confirms grinding is the cause.

Can stress cause jaw pain on one side? 

Yes, and it's one of the most common triggers around. Stress makes people clench and grind, often at night and often unevenly, which loads one side of the jaw more than the other. Managing the stress helps, but protecting the jaw with a splint usually gives faster relief.