Sinuses are air-filled cavities located within the bones of the face and skull. They are lined with mucous membranes and play a crucial role in humidifying and filtering the air we breathe, as well as producing mucus to keep the nasal passages moist and trap foreign particles. Most of us have four pairs of sinuses as shown in the image below.
Frontal Sinuses
The frontal sinuses are paired cavities that lie behind your frontal bone within your forehead. Obstruction of the drainage pathway and associated infection can cause frontal sinusitis, resulting in symptoms such as headaches, pressure, and tenderness over the forehead.
Ethmoid Sinuses
The ethmoid sinuses are a complex system of small, air-filled cavities located between the eyes, behind the bridge of the nose. They consist of numerous thin-walled cells separated by delicate bony partitions called ethmoidal air cells. They can be divided into anterior ethmoid (towards the front) and posterior ethmoid (towards the back). Inflammation of the ethmoid sinuses can lead to symptoms such as facial pain, nasal congestion, and postnasal drip.
Maxillary Sinuses
The maxillary sinuses are the largest of the paranasal sinuses and are located within the maxillary bones (which are behind your cheeks). Infection or inflammation of the maxillary sinuses can cause symptoms such as facial pain, and pressure in the cheeks and toothache (although often infections in the root of your teeth can trigger infection within these sinuses).
Sphenoid Sinuses
The sphenoid sinus is located deep within the skull, behind the nose and eyes. Inflammation or infection of the sphenoid sinus can cause symptoms such as headache, earache, and neck pain.
