QS Study

The paranasal sinuses are air-filled spaces located within the bones of the skull and facial bones. The paranasal air sinuses are the air-filled spaces present within bones around the nasal cavities.

Clinical anatomy of Paranasal Sinuses

Infection of a sinus is known as sinusitis. It causes a headache and persistent, thick, purulent discharge from the nose. Diagnosis is assisted by transillumination and radiography. A diseased sinus is opaque. They are situated around the nasal cavity and they are all paired and sometimes symmetrical, while always being bilateral. The sinuses develop as outgrowths from the nasal cavity; hence they all drain directly or indirectly into the nose. Nasal infection (rhinitis), e.g., during a “cold in the head,” may spread to the sinuses (sinusitis).

Clinical anatomy of Paranasal Sinuses 1

Fig: Clinical anatomy of Paranasal Sinuses

The maxillary sinus is most commonly involved. It may be infected from the nose or from a carious tooth. Drainage of the sinus is difficult because its ostium lies at a higher level than its floor. Another factor is that cilia in the lining mucosa are destroyed by chronic infection. The superior border of this sinus is the bony orbit, the inferior is the maxillary alveolar bone and corresponding tooth roots, the medial border is made up of the nasal cavity and the lateral and anterior border are limited by the cheekbones. The sinuses develop mostly after birth, and their degree of development varies greatly. Hence the sinus is drained surgically by making an artificial opening near the floor in one of the following two ways.

(a) Antrum puncture can be done by breaking the lateral wall of the inferior meatus,

(b) An opening can be made at the canine fossa through the vestibule of the mouth, deep to the upper lip (Caldwell-Luc operation.)

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