Most people have already experienced the characteristic pain and pressure sensations caused by a sinus infection. For some, every little common cold is liable to give rise to a sinus infection. The good news: Home remedies are often all it takes to resolve the symptoms. However, that is not true for the ten percent who suffer from chronic sinusitis. The maxillary sinuses are two cavities situated in the upper jaw bone, left and right from the nose. With up to 15 cubic centimetres volume, they are the largest of the paranasal sinuses. At their lower perimeter, they are separated from the oral cavity by nothing but a thin bone lamella that forms the tooth sockets of the upper jaw molars. Their upper perimeter is caved in, forming the eyes’ orbital floor. Like the other paranasal sinuses, the maxillary sinuses are connected to the nasal cavity, through openings that are located in the upper part of the nasal passages (that means, they cannot be drained by gravity!). The maxillary sinuses are filled with air and lined, just like the nose, with a special mucosa of about one millimetre thickness. Part of this mucosa are cells that produce mucus and cells with moving ciliae. Those play an active part in the removal of dust and microorganisms.
Sinusitis maxillaris: A case for the dentist? Or for the ear-nose-throat-specialist?
That depends on whether the sinusitis originates from the nose (rhinogenic), or from the teeth (dentogenic). A rhinogenic sinusitis is normally not a something you must see a dentist about, but rather a case for your family physician or an ear-nose-throat specialist. Sometimes patients mistake pain in the region of the cheeks for a toothache, though, and come to a dental office first. That’s OK, too: We can make the diagnosis and refer you to the right specialist if your sinusitis turns out to be rhinogenic. And if it is dentogenic, you have come to the right place!
Rhinogenic sinusitis
Rhinogenic means as much as: originating in the nose. Viruses, bacteria, fungal spores and allergenes can make the passage from the nose into the maxillary sinus via the connecting opening – and they do that all the time. Normally they get stuck in the mucus and are instantly expedited back to the nose by the moving ciliae of the mucosal sinus lining.
Pathogenesis
However, if the mucosa of nasal and maxillary sinus cavity swell up due to a cold or an allergic reaction, the opening between nose and sinus may become blocked. Liquid collects in the warm cavity, making it an ideal breeding ground for pathogens. Some people have a narrow opening between nose and maxillary sinus to begin with.
For them, such blockages are much more likely and occur more frequently. Acute maxillary sinusitis often develops in connection with a common cold. Inflammations that persist longer than two months are referred to as chronic sinusitis. The permanently inflamed state of the sinus mucosa may lead to a typical complication: mucosal proliferations called polyps.
Symptoms
Symptoms of an acute sinusitis are a feeling of pressure that may occur on one or both sides of the face, and a pressing or throbbing pain in the region of the head or cheeks. A characteristic sign of a sinusitis maxillaris is the sharp pain that occurs in the affected sinus after a slap on the back of the head. Purulent nasal discharge or a permanently stuffed nose are other fairly typical symptoms of infected sinuses.
In severe cases, the disease may be accompanied by fever and a strong feeling of fatigue. In cases of chronic sinusitis, the acute symptoms of the disease often present themselves in a “watered down” form: there may be a permanent feeling of dull pressure and runny nasal discharge. In the long run, loss of smell is not a rare occurence.
Treatment
The acute rhinogenic sinusitis is treated with measures that improve drainage from the sinus cavity and reduce inflammation. Drainage is improved by a) dilution of the discharge (drink lots, steam inhalation, nasal irrigation, infrared therapy and expectorant (mucolytic) medication) and b) medication that reduces the swelling of the mucosa (nose sprays or drops – caution: those medications damage the mucosa with long term use!). Preparations with cortisone suppress the symptoms of inflammation.
They are prescribed mainly for rhinogenic sinusitis caused by allergic reactions. Since the pathogens are viruses in most cases of acute rhinogenic sinusitis, antibiotics are not the standard treatment. Antibiotic medication will be prescribed when bacterial involvement is proven or can be reasonably assumed. Symptoms lasting longer than ten days point towards a bacterial sinusitis. The conservative therapy of a chronic sinusitis is long-term antibiotic or cortisone treatment.
Surgical treatment
If the conservative treatment of a chronic sinusitis fails, the ENT-specialist will consider surgical treatment. The preferred modern method is minimally invasive endoscopic reopening of the sinus drain. Two small endocope channels are inserted into the sinus cavity. One contains a fiber optic light guide and a camera to illuminate and inspect the sinus. The other channel can be used to introduce a flushing solution and/or small surgical instruments that may remove tissue proliferations and widen the connection between the nasal and sinus cavities by chiselling away small pieces of bone.
If the symptoms persist, an additional permanent window between nose and sinus cavities in the lower or middle nasal passage (antrostomy) may be surgically created to improve drainage and ventilation of the sinus cavity. A third surgical possibility is opening up (and cleaning out) the sinus cavity from the oral cavity (osteoplastic sinus operation, bone flap procedure). After removing a small piece of bone from the sinus floor (it is later replaced), the surgeon has free access to the sinus cavity. The osteoplastic sinus operation is a last resort for sinus infections that don’t respond to all other forms of treatment, and it is the only surgical option for problems that cannot be addressed via endoscopic access through the nose: cysts, tumors or displaced teeth that have emerged in the sinus cavity. Sinus surgery is usually a walk-in procedure. Endoscopic surgery is performed under local anaesthesia. Osteoplastic operations may require general anaesthesia.
Dentogenic sinusitis
Dentogenic means: originating from the teeth. Dentogenic sinus infections are caused by germs that enter the sinus cavity from the oral cavity. Successful treatment must first address the causative dental problem.
Pathogenesis
Besides the opening between sinus and nasal cavities, the thin bone lamella between oral and sinus cavities is another potential entryway for pathogens. Long lasting inflammations in the root region of molars, inflammations around implants (periimplantitis) and upper jaw cysts may dissolve the bony sinus floor, releasing bacteria into the sinus.
Perforation of the sinus floor may sometimes occur during a tooth extraction, root tip resection or implantation procedure. After each of these operations, the dentist or oral surgeon must verify whether an accidental perforation has occured.
The reliable test goes like this: Pinching their nose shut, patients build up pressure in the nasal cavity by exhaling into the nose. A perforation of the sinus floor will reveal itself by an audible leakage of air into the oral cavity (Unpleasant, we agree. But it needs to be done).
Any accidental hole in the sinus floor must be immediately closed with a flap of gum tissue to prevent complications, as pathogens or debris from a tooth entering the sinus cavity via this opening will infallibly cause a sinus infection. In rare cases, the long roots of the last two molars may grow through the floor into the sinus cavity. As long as those teeth are healthy, everything is fine. If an infection develops in their root region, however, it can easily spread into the sinus. If those molars are extracted, the resulting opening in the sinus floor must be closed immediately.
Treatment
For successful treatment of a dentogenic sinusitis, the infection and inflammatory processes around teeth and gums must be addressed first. Inflamed root tips, periimplantitis, deep gingival pockets or upper jaw cysts may be responsible for a dentogenic sinusitis.
After these causes are treated with the appropriate methods by the dentist or oral surgeon, the sinus infection will resolve itself in most cases – provided that the nasal drain of the sinus cavity is free. Antibiotics may be prescribed to insure fast and complete healing. Special therapeutic indications (i.e., tooth debris in the sinus cavity) may warrant an osteoplastic sinus operation.