Maxillary sinusitis is a common inflammation affecting the air-filled cavities located in the facial bones. This condition occurs when the lining of these spaces becomes swollen, hindering the normal movement of mucus and air. The resulting buildup leads to discomfort and other noticeable symptoms. The maxillary sinuses are frequently involved due to their location and drainage pathway.
Defining the Maxillary Sinuses and Sinusitis
The paranasal sinuses are a group of four paired air-filled spaces situated within the skull and facial bones. The maxillary sinuses, also called the antrum of Highmore, are the largest of these cavities and are shaped like a pyramid. They are located beneath the eyes, on either side of the nose, and above the upper teeth.
The primary function of healthy sinuses is to produce mucus that cleanses the nasal passages, filter and humidify inhaled air, and help lighten the skull. The maxillary sinuses drain into the middle meatus of the nose through a small opening called the ostium.
Maxillary sinusitis refers specifically to the inflammation of the mucous membrane lining the maxillary sinuses. When this lining swells, the small ostium can become blocked, preventing normal mucus drainage. This obstruction creates a warm, moist environment where trapped fluids can become a breeding ground for infectious agents. This inflammation can be categorized as acute, lasting less than four weeks, or chronic, persisting for 12 weeks or longer.
Triggers and Underlying Causes
The inflammation that characterizes maxillary sinusitis falls broadly into infectious and non-infectious categories. The most frequent cause is a viral infection, such as the common cold, which leads to swelling and mucus buildup that spreads to the sinuses. If symptoms persist beyond seven to ten days, a secondary bacterial infection may develop, as the blocked sinus cavity offers an ideal environment for bacterial growth.
Less commonly, fungal organisms can cause sinusitis, particularly in individuals with compromised immune systems or those with certain allergic conditions. Non-infectious triggers include allergic rhinitis, where exposure to environmental allergens like pollen or dust leads to inflammation and congestion. Anatomical issues, such as a deviated nasal septum or the presence of nasal polyps, can also physically obstruct the drainage pathway, making inflammation and infection more likely.
A distinguishing cause specific to the maxillary sinus is odontogenic sinusitis, which originates from a dental issue. The roots of the upper teeth are in close proximity to the sinus floor, separated by a thin layer of bone. Infections from dental abscesses, decay, or complications following procedures can penetrate this barrier. This type of infection is responsible for an estimated 10 to 12% of all chronic sinusitis cases and is often unilateral.
Recognizing the Signs
The symptoms of maxillary sinusitis often present as facial discomfort, distinct from a typical head cold. The most commonly reported sign is pain or pressure felt directly in the cheek area, just below the eyes. This pressure may intensify when the person bends forward or lowers their head. Many individuals also experience referred pain in their upper teeth, which can mistakenly be attributed to a primary dental problem.
This referred pain occurs because the maxillary nerve supplies sensation to both the sinus lining and the upper teeth. Nasal symptoms include a thick, discolored discharge, often yellow or green, that may drain from the nose or down the back of the throat, known as post-nasal drip. This drainage can lead to a persistent cough, bad breath, or a bad taste in the mouth.
Inflammation and congestion can also impair the sense of smell and taste. If the condition is an acute infection, systemic symptoms such as fatigue or a low-grade fever may also be present.
Treatment and Recovery Pathways
The initial approach to managing maxillary sinusitis depends on whether the condition is acute or chronic and the suspected underlying cause. A diagnosis is typically confirmed through a physical examination and often involves imaging, such as a computed tomography (CT) scan, to assess the extent of the inflammation and blockage. The goal of all treatment is to reduce inflammation, promote drainage, and eliminate any infectious agents.
For most acute cases, particularly those suspected to be viral, supportive care is the primary treatment pathway. This includes using saline nasal rinses, inhaling steam, and taking over-the-counter pain relievers. Nasal corticosteroid sprays may also be prescribed to reduce the swelling of the sinus lining and help reopen the drainage ostium.
If a bacterial infection is confirmed or strongly suspected, antibiotics may be prescribed. Antibiotics are reserved for bacterial infections, as they are ineffective against viral or fungal causes.
For chronic sinusitis, or cases that do not respond to medication, functional endoscopic sinus surgery (FESS) may be considered. FESS is a minimally invasive procedure designed to enlarge the natural sinus opening, improving ventilation and drainage. If the cause is odontogenic, the underlying dental infection must be treated first before the sinus inflammation can resolve.