Inflammation of the NASAL MUCOSA in the SPHENOID SINUS. Isolated sphenoid sinusitis is uncommon. It usually occurs in conjunction with other paranasal sinusitis.

Inflammation of the NASAL MUCOSA in one or more of the PARANASAL SINUSES.

Surgery performed on the ear and its parts, the nose and nasal cavity, or the throat, including surgery of the adenoids, tonsils, pharynx, and trachea.

An irregular unpaired bone situated at the SKULL BASE and wedged between the frontal, temporal, and occipital bones (FRONTAL BONE; TEMPORAL BONE; OCCIPITAL BONE). Sphenoid bone consists of a median body and three pairs of processes resembling a bat with spread wings. The body is hollowed out in its inferior to form two large cavities (SPHENOID SINUS).

One of the paired air spaces located in the body of the SPHENOID BONE behind the ETHMOID BONE in the middle of the skull. Sphenoid sinus communicates with the posterosuperior part of NASAL CAVITY on the same side.

Formation or presence of a blood clot (THROMBUS) in the CAVERNOUS SINUS of the brain. Infections of the paranasal sinuses and adjacent structures, CRANIOCEREBRAL TRAUMA, and THROMBOPHILIA are associated conditions. Clinical manifestations include dysfunction of cranial nerves III, IV, V, and VI, marked periorbital swelling, chemosis, fever, and visual loss. (From Adams et al., Principles of Neurology, 6th ed, p711)

Inflammation of the NASAL MUCOSA in the MAXILLARY SINUS. In many cases, it is caused by an infection of the bacteria HAEMOPHILUS INFLUENZAE; STREPTOCOCCUS PNEUMONIAE; or STAPHYLOCOCCUS AUREUS.

Inflammation of the NASAL MUCOSA in the ETHMOID SINUS. It may present itself as an acute (infectious) or chronic (allergic) condition.

Inflammation of the NASAL MUCOSA in the FRONTAL SINUS. In many cases, it is caused by an infection of the bacteria STREPTOCOCCUS PNEUMONIAE or HAEMOPHILUS INFLUENZAE.

Diseases affecting or involving the PARANASAL SINUSES and generally manifesting as inflammation, abscesses, cysts, or tumors.