The maxillary sinuses are hollow, air-filled cavities located within the maxillary bones, more commonly known as the cheekbones, on either side of the nose. As the largest of the four pairs of paranasal sinuses, they are pyramidal in shape. Their development is a lengthy process, beginning in the fetal stage and expanding significantly throughout childhood and adolescence. This gradual growth contributes to the changing shape of the face from infancy to adulthood.
Anatomy and Function of the Maxillary Sinus
The primary role of the maxillary sinuses is respiratory. As you inhale, the air passing through these chambers is warmed and humidified before it reaches your lungs. The sinuses are lined with a special mucous membrane that produces a thin layer of mucus.
This mucus acts as a trap for dust, pollen, and other airborne debris. The membrane is also covered in microscopic, hair-like structures called cilia. These cilia move in a coordinated, wave-like motion to propel the mucus toward a small opening called the ostium. This opening connects the sinus to the nasal cavity for drainage. This entire mechanism is referred to as mucociliary clearance, and the sinuses also contribute to the resonance of your voice and reduce the overall weight of the skull.
Common Conditions and Symptoms
Inflammation of the maxillary sinus is known as maxillary sinusitis. This inflammation can be triggered by several factors, with viral infections like the common cold being a frequent cause. Allergies can also lead to sinus inflammation by causing the mucous membranes to swell. In some cases, a bacterial infection can develop, often as a complication of a preceding viral illness when mucus drainage is blocked.
The symptoms of maxillary sinusitis often involve a sense of pressure or pain in the cheeks, which may worsen when bending forward. Headaches, particularly in the frontal region, are also common. Sufferers may experience nasal congestion and a thick, discolored nasal discharge that can be yellow or green. A notable symptom is pain or a feeling of pressure in the upper teeth, a direct result of the proximity of the tooth roots to the inflamed sinus floor.
The Dental Connection
The relationship between the maxillary sinus and the upper teeth is significant for both dental and sinus health. The floor of the maxillary sinus is located directly above the roots of the posterior maxillary teeth, specifically the premolars and molars. In many individuals, the bone separating the tips of these tooth roots from the sinus cavity is exceptionally thin. This anatomical closeness creates a direct pathway for infection to travel between the oral cavity and the sinus.
A common issue arising from this relationship is odontogenic sinusitis, which accounts for a substantial percentage of maxillary sinusitis cases. This condition occurs when a dental infection, such as a large cavity that leads to a tooth abscess, erodes through the thin layer of bone and spreads into the sinus lining. Another consideration is the potential for an oroantral communication, which is an opening between the mouth and the sinus, to form after the extraction of an upper molar.
This connection explains why dentists are often involved in diagnosing and managing what might initially seem like a purely sinus-related problem. The evaluation of the upper teeth is a standard part of diagnosing persistent maxillary sinus issues.
Diagnosis and Treatment Options
Diagnosing issues within the maxillary sinus begins with a physical examination and a review of your symptoms. A healthcare provider may use a technique called transillumination, where a bright light is shone against the cheek to see if light passes through the sinus. For a more detailed view, a nasal endoscopy may be performed, which involves inserting a thin, flexible tube with a camera into the nose to directly visualize the sinus opening. A computed tomography (CT) scan is often the preferred method for precise imaging as it provides detailed cross-sectional images of the sinuses.
Treatment for maxillary sinus conditions varies based on the underlying cause. For sinusitis caused by a viral infection, treatment focuses on managing symptoms with rest, hydration, and over-the-counter decongestants or saline nasal rinses. If a bacterial infection is suspected, a course of antibiotics may be prescribed. For inflammation driven by allergies, nasal corticosteroid sprays are frequently used to reduce swelling.
In cases of chronic or recurrent sinusitis that do not respond to medication, surgical intervention might be considered. Functional Endoscopic Sinus Surgery (FESS) is a minimally invasive procedure designed to enlarge the natural drainage pathway of the sinus. When dental implants are needed in the upper jaw and the sinus floor is too low, a sinus lift procedure may be performed. This surgery involves adding bone graft material to the sinus floor to create a stable foundation for the implant.