Sinus pressure can feel miserable. Congestion, facial pain, and headaches are often blamed on allergies or a cold. However, in some cases, the real cause may not be your sinuses at all — it could be a tooth.

Many patients are surprised to learn there is a connection between a root canal and sinus pain. Upper back teeth sit very close to the sinus cavity. When infection develops in those teeth, it can irritate the sinus lining and cause symptoms that feel like sinus trouble.

At Eastern Idaho Endodontics, we often evaluate patients who thought they had sinus issues, only to discover a dental infection was the source.

How Are Teeth and Sinuses Connected?

The roots of the upper molars and premolars sit just beneath the maxillary sinus. In some people, the roots are extremely close to — or even touching — the sinus floor.

Because of this proximity, infection at the tip of a tooth root can spread inflammation into the sinus cavity.

This is why dental problems sometimes feel like sinus infections.

Symptoms That May Point to a Dental Cause

Sinus pain caused by a tooth infection often feels slightly different than a traditional sinus infection. Watch for these signs:

  • Pressure or pain near the cheekbones

  • Pain that worsens when biting or chewing

  • Sensitivity in an upper back tooth

  • A dull, persistent ache on one side of the face

  • Swelling in the gums near the affected tooth

Unlike seasonal allergies, dental-related sinus pain is often localized to one side.

Can a Root Canal Infection Affect the Sinuses?

Yes. A root canal infection in an upper molar can irritate or inflame the nearby sinus cavity. In some cases, this may lead to sinus congestion or pressure that does not improve with antibiotics prescribed for sinus infections.

If the infection is dental in origin, treating the tooth is the only way to fully resolve the issue.

How a Root Canal Can Relieve Sinus Pain

When a tooth infection is causing sinus irritation, root canal treatment removes the source of bacteria inside the tooth. Once the infection is eliminated, inflammation in the sinus often subsides as well.

Patients frequently report noticeable relief after dental treatment when the sinus symptoms were tooth-related.

How Do We Determine the Cause?

Diagnosis is key. Advanced imaging helps identify whether the infection is originating from the tooth root or the sinus cavity itself.

Signs pointing to a dental source include:

  • Infection visible at the tip of a tooth root

  • Bone loss around the root

  • Localized swelling or tenderness

If imaging confirms a dental infection, treatment can begin promptly.

What If It’s Just Sinus Pressure From a Cold?

Sometimes sinus congestion from a cold can make teeth feel sore. This happens because sinus pressure pushes downward on the tooth roots.

The difference is this:

  • Sinus-related tooth discomfort usually affects multiple upper teeth

  • Dental infection pain is often isolated to one specific tooth

If the discomfort fades as the cold improves, it was likely sinus pressure. If it persists, a dental evaluation is recommended.

When Should You Seek Care?

You should schedule an evaluation if:

  • Sinus pressure is persistent and one-sided

  • Tooth pain accompanies sinus symptoms

  • Antibiotics for sinus infection do not resolve symptoms

  • Chewing causes discomfort in a specific upper tooth

Early diagnosis prevents complications and avoids unnecessary sinus treatments.

Final Thoughts

The connection between a root canal and sinus pain is real. Because upper back teeth sit so close to the sinus cavity, infection can mimic sinus problems.

If you are experiencing facial pressure along with tooth discomfort, a dental evaluation may provide the answers you need.

Treating the source of infection — rather than masking symptoms — is often the key to lasting relief.