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Could a Tooth Infection be the Source of Chronic Sinus Problems?

Frequent sinus infections may be cured by specialized dental care offered by endodontists.

CHICAGO – According to Dr. Michael J. Lewis, a root canal specialist, chronic sinus infections are sometimes caused by an underlying tooth infection.

“In short, sometimes the roots of one’s teeth become infected, and that infection can spread to their sinuses.” Dr. Lewis said.

This medical condition Dr. Lewis referred to is called Maxillary Sinusitis of Endodontic Origin (MSEO). Most people do not realize it, but the roots of the upper back teeth often extend quite close to a hollow air-filled space located behind their cheekbones called the maxillary sinus. If one of these upper back teeth becomes infected, the infection can spread rather easily out of the end of the tooth’s root and spread into the maxillary sinus. Patients suffering with MSEO will often exhibit low grade sinus or nasal symptoms including post nasal drip or general sinus congestion which they may think is due to seasonal allergies.

Some patients may even experience recurring sinus infections, which are often treated by their physician with antibiotics. While antibiotics will resolve the patient’s sinus symptoms for a period, the antibiotics are incapable of reaching the source of the infection inside the tooth. Once the antibiotics are ceased, the infection will slowly re-emerge from the tooth and spread back into the sinus and the symptoms will often recur many months later.

Ironically enough, patients with MSEO often do not exhibit any tooth pain. This absence of dental symptoms can make it very difficult for both the patient and their medical doctor or general dentist to recognize that there is even a tooth infection present. As a result, patients often suffer from this condition for many years before it is recognized. While the diagnosis of MSEO can be difficult to arrive at, endodontists are specially trained and equipped to diagnose and treat this condition.

Dr. Lewis says easy and relatively painless treatment options like a root canal therapy can help eliminate the bacteria that are causing these infections. In some cases, the MSEO infection is originating from a tooth that has already undergone root canal treatment once before, but is now failing. For those patients dealing with a failing root canal, the specialized training endodontists undergo allows them to offer remedial services such as retreatment that can predictably eliminate the infection inside the tooth even where past efforts by other practitioners may have failed.

“Many people may cringe at the thought of having root canal treatment, but in the hands of a skilled practitioner, the process is quite effective, easy, and relatively painless,” Dr. Lewis continued. “For those patients diagnosed with MSEO, root canal therapy or retreatment may completely resolve their sinus symptoms, with about half of all patients experiencing the procedure requiring no other medical care. Patients who do not experience relief may require additional care from an ENT to fully resolve their complaints, though a root canal treatment is often a necessary first step.

Dr. Lewis received his dental degree from the University of Pennsylvania in 2004 and completed his advanced specialty endodontic training at the New York University School of Dental Medicine. He is a member of the American Association of Endodontists.

To learn more about MSEO, interested parties are encouraged to sign up for the AAE’s webinar being offered Feb. 21, 2019, or refer to articles featured in Dear Doctor or Decisions in Dentistry.


About the American Association of Endodontists
The American Association of Endodontists, headquartered in Chicago, Ill., represents more than 8,000 members worldwide. Endodontics is one of nine dental specialties formally recognized by the American Dental Association. The AAE, founded in 1943, is dedicated to excellence in the art and science of endodontics and to the highest standard of patient care. The Association inspires its members to pursue professional advancement and personal fulfillment through education, research, advocacy, leadership, communication and service. For more information about the AAE, visit the Association’s website at

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