Cracked Tooth or Sinus Infection? How to Tell the Difference

A dull ache behind your cheekbones and soreness in your upper teeth can be difficult to interpret. A tooth problem can feel like sinus pressure, while sinus disease can cause pain felt in otherwise healthy teeth. Symptoms overlap, so a checklist cannot reliably tell you which treatment you need.

Why These Conditions Feel Similar

Upper premolars and molars lie close to the maxillary sinuses. Pain felt in this area does not necessarily identify its source. A cracked tooth, inflammation around a root and sinus-origin referred pain are different problems that may need different care.

Symptoms to Discuss with Your Clinician

Tell your clinician about congestion, drainage, recent respiratory illness, changes with posture, tooth sensitivity and pain on biting. One-sided symptoms can prompt a dental assessment, but do not prove a dental cause. Lack of toothache or cold sensitivity does not exclude an infected tooth.

Fever or feeling unwell can accompany dental as well as sinus infections. Discharge color alone does not establish a bacterial infection. Do not use either feature to choose your own diagnosis or antibiotic treatment.

When a Cracked Tooth Is Possible

Sharp pain with biting or release, lingering cold sensitivity, or a history of a large restoration may prompt assessment for a crack. These findings are not specific enough to diagnose a crack by themselves. Cracks can be difficult to locate, and neither a normal X-ray nor a negative CBCT reliably excludes every crack. A dental examination helps establish the tooth's condition and whether it can be restored.

When a Tooth Infection Contributes to Sinus Disease

Infection in an upper tooth's root canal system can be associated with inflammation around the root and sinus disease, sometimes without toothache. This is called maxillary sinusitis of endodontic origin, or MSEO. It is one part of the broader category of odontogenic sinusitis: periodontal disease, extraction-related openings, implants or displaced dental material can also contribute, and require different management.

Published studies use different populations and definitions. Their percentages should not be treated as your personal chance of having MSEO. Dental and non-dental sinus disease can coexist. Read our patient guide to MSEO for more context.

How the Difference Is Evaluated

A clinician combines your history with an examination and appropriate imaging rather than relying on one test:

• Tooth and periodontal examination. Cold or electric pulp testing, percussion, palpation, probing and bite testing can help identify patterns. No single absent or positive response establishes the diagnosis.
• Magnification when appropriate. A microscope can assist examination for a crack or other tooth problem, but does not guarantee that every cause will be found.
• Selectively indicated imaging. Existing dental and sinus images should be reviewed first. Dental X-rays may answer the question; CBCT imaging may be justified if an unresolved question would change care. Low and colleagues found additional imaging findings in teeth referred for possible apical surgery, not proof that every patient with sinus pain needs CBCT.
• Clinical correlation and ENT coordination. Sinus-lining thickening alone does not prove symptomatic sinusitis or a dental cause. A limited dental scan may not cover the entire sinus drainage system. Persistent or unexplained sinus symptoms may need ENT assessment.

Treatment and Follow-up

When an infected endodontic source is identified, root canal treatment, retreatment, root-end surgery or extraction may be appropriate, depending on the tooth. Antibiotics can be needed in selected circumstances but do not replace treatment of an infected root canal source. Treating a tooth does not guarantee that all sinus symptoms will resolve. Observational studies by Tomomatsu and Wang reported differing treatment courses, including additional sinus surgery in some patients. Follow-up and coordinated care matter; there is no universal recovery timeline.

What to Do Now

Arrange an assessment for persistent or worsening pain or sinus symptoms. Do not use a decongestant trial as a diagnostic test. Improvement or lack of improvement does not reliably distinguish dental from sinus disease. Ask a clinician or pharmacist about medicines rather than delaying evaluation to experiment.

Seek urgent medical care for difficulty breathing or swallowing, swelling around the eye, vision changes, or rapidly spreading facial swelling. Fever with swelling also needs prompt assessment. Do not wait for a routine dental appointment when serious symptoms are present.

Arrange an Evaluation

Bring previous dental images, sinus CT reports and details of dental or sinus treatments. Dr. Kung can assess possible endodontic disease and discuss whether further imaging or ENT coordination is needed. Some cases require more than one visit.

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Evidence update: The AAE committee's Maxillary Sinusitis of Endodontic Origin, DOI 10.1016/j.joen.2026.10.019, was accepted October 30, 2026. The supplied 2026 journal pre-proof is not the definitive Version of Record and may change during production. It is a bibliographic reference, not reproduced or rewritten here. The clinical corrections above are independently written using the underlying research. This editorial revision and its translations have not been clinically reviewed.