Sinusitis and Tooth Infections
Chronic sinus problems may have a dental cause
Dear Doctor,
I get sinus infections every year. My doctor suggested I see an endodontist. How could seeing a dental specialist help with my problem?
Dear Bradon,
I am glad to hear that your doctor recommended seeing an endodontist. An endodontist is a dentist who specializes in treating infections inside the teeth. All too often, a possible connection between chronic sinus problems and tooth infections is overlooked. Yet it is very easy for a bacterial infection that starts in an upper back tooth (molar or premolar) to spread into the sinus. To understand how this happens, let's take a look at how a tooth can get infected in the first place.
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| A cat scan x-ray reveals a bacterial infection inside the root canals of an upper molar from tooth decay that has spread into the sinus. This condition is called Maxillary Sinusitis of Endodontic Origin (MSEO). |
A tooth infection begins when acid-producing bacteria create a small cavity (hole) on the outer portion of your tooth. If this cavity is not treated, these harmful bacteria can work their way deeper inside the tooth until they penetrate into the hollow space inside the tooth. These hollow spaces, called root canals, extend all the way down to the tips of the roots (which are beneath the gums). The root canals contain living tissue including nerves and blood vessels, which can become infected by these bacteria. Often the tooth will be very sensitive to hot and cold in the early stages of infection. As the infection continues to progress, it will try to spread out past the end of the root and the bone around the tip of the root will begin to break down. This stage is often associated with pain when biting.
Temperature sensitivity, pain when biting or signs of a breakdown of bone on an x-ray are the main signs and symptoms by which a dentist can determine if you have a tooth infection. Root canal therapy is a procedure that is designed to eliminate the infection inside the tooth without having to remove the tooth. Root canal therapy has two goals. The first goal is to clean out the inside of the root canal and eliminate as many bacteria as possible. In this stage, the doctor is also trying to eliminate any tissue and fluid from within the canal space that might serve as a potential food source for the bacteria. The second goal is to fill in and seal the now clean and empty canal space in order to prevent new bacteria and new fluid or food sources from entering the space. Even if there are a few bacteria remaining they will be starved of the nutrition they need to survive. If both these goals are accomplished, the infection will be eliminated and the body can heal.
Root canal treatment must be done meticulously for it to work—and this is not an easy task. That's especially true for the upper molar teeth which can have "extra" canals that are often difficult to detect and as a result are often not cleaned properly. Occasionally, an infection from one of these overlooked canals will emerge months or even years after the original root canal treatment, and a root canal re-treatment may be required. Endodontists are trained to deal with complex teeth and confusing diagnoses and are usually the best option to perform remediation procedures such as re-treatment.
Though "getting a root canal" has a bad rap, the procedure can actually be performed with very little discomfort. A local anesthetic (numbing shot) is always administered, along with any sedation that may be necessary. A dental crown (cap) is usually needed to completely restore the tooth.
The Dental-Sinus Connection
In the case of an infected upper back tooth, breakdown of bone at the tip of the root can create a passageway for the infection inside the tooth to spread into a nearby area called the maxillary sinus. The maxillary sinus is a hollow air-filled space behind your cheek bones. Depending on your own unique anatomy, the roots of the upper premolars and molars can extend quite close to the floor of the maxillary sinus, or even poke through it. If you have this type of anatomy, a tooth infection can spread quite easily into your maxillary sinus. This condition is called Maxillary Sinusitis of Endodontic Origin or MSEO.
The tricky part of diagnosing tooth infections causing MSEO is that the tooth in question will typically not exhibit temperature sensitivity, pain when biting or signs of a breakdown of bone on an x-ray. This absence of traditional tooth symptoms can make it very difficult for both the patient and their general dentist to recognize that they have a tooth infection. Indeed, it is not unusual for MSEO to go unrecognized for many years. Instead of tooth pain, a person may complain of chronic post-nasal drip and sinus congestion which they may incorrectly think are due to allergies. Some people will experience repeated episodes of acute sinus infection with a fever. Their doctor or ENT (ear, nose and throat specialist) may prescribe antibiotics, which will temporarily relieve those symptoms. Unfortunately, antibiotics delivered through the bloodstream cannot reach that little bacteria factory deep inside the tooth because there is no longer any blood flow in the tooth. Sooner or later those bacteria will spread into the sinus again, and those highly annoying sinus symptoms will recur several months later.
Is this what's happening in your case? That's what an endodontist is specially trained to figure out. Using advanced technology such as 3-D cone beam computed tomography (CBCT) scans, endodontists can carefully examine your teeth and your sinus and help determine whether you are suffering from MSEO. If a tooth infection is found, root canal treatment or retreatment will be recommended. One study found that endodontic treatment alone will resolve sinus symptoms in roughly half the cases—with no other medical treatment needed. In the other half, the person may need additional treatment from an ENT physician to fully resolve their symptoms.
Endodontists are root canal specialists who are specially trained and equipped to recognize and treat difficult tooth infections. While all dentists are trained in basic root canal procedures, many general dentists choose to refer patients with more complex endodontic problems to an endodontist. If you need to find an endodontist near you, please go to the website of the American Association of Endodontists at www.aae.org/patients/.
