A sinus infection (sinusitis) can cause a toothache. In fact, pain in the upper back teeth is a common symptom of sinus conditions.

Sinusitis is a common disease affecting more than 35 million people in the US each year. Even though it is incredibly common, sinus infections are still among the most frequently misdiagnosed diseases in clinical practice.

Sinusitis is inflammation of the paranasal air sinuses caused by infection. Maxillary sinusitis is therefore an inflammation of the maxillary sinus.

The maxillary sinus (or antrum of Highmore) is the largest of your sinuses. Once your maxillary sinus is inflamed, it is possible for the infection to then spread to the orbit or to the ethmoid sinus. The maxillary sinus is incredibly close to the maxillary teeth. In fact, it can often be seen on a dental x-ray situated above the molar and pre-molar teeth in the upper jaw. Because of this, it allows for the easy spread of infection. An odontogenic infection is an infection that originates within a tooth.

Odontogenic sinusitis was previously thought to account for up to 10% of all maxillary sinusitis cases. However, most recent studies have shown that it is closer to a much higher figure of 40% of chronic bacterial maxillary sinus infections attributed to a dental source.

Odontogenic sinusitis has been a well-recognized condition for over 100 years. If a dental infection or dental/oral surgery ruptures the Schneiderian membrane, it can often lead to sinusitis.

Most Common Causes of Odontogenic Sinusitis
Most commonly, a periodontal disease or dental abscess is the cause of odontogenic sinusitis. These often perforate the Schneiderian membrane and lead to infection. Another incredibly common cause is perforations of the maxillary sinus during tooth extractions. Therefore, you should consider ruling out odontogenic sinusitis if you experience symptoms after recently having a tooth removed. In a recent study of 27 patients with odontogenic sinusitis, over 35% contracted the infection due to dental implant-related complications. Making this another common cause.

The symptoms of maxillary sinusitis, whether it be of the dental origin or otherwise, are often the same. In most cases, symptoms will include headaches (in the sinus areas), pharyngeal or nasal discharge, which is usually foul-smelling, as well as normal signs of infection such as a fever.

The sinus areas can be particularly tender to touch and feel hot as well as appear red and swollen. Moreover, due to its proximity to the maxillary teeth, there can be pain that feels dentally related regardless of whether it originated there or not.

Determining Dental Origin for Sinusitis
If someone has had a history of jaw pain, or odontogenic infection or has recently undergone any form of oral surgery and is experiencing symptoms of maxillary sinusitis, then an odontogenic source should be considered.

Odontogenic sinusitis is completely different from sinusitis of other causes in terms of its pathophysiology, microbiology, diagnostics, and management. Therefore, if it is failed to be appropriately identified patients can end up with prolonged symptoms as well as failed surgical and medical therapies.

Previously, dental films and dental evaluations were most used for diagnosing odontogenic sinusitis. However, these methods frequently fail to detect a maxillary dental infection that can be causing odontogenic sinusitis.