Paranasal Sinus

**Semantic type:** Anatomical Structure

**Definition:** Any one of the air-filled spaces within the ethmoid, frontal, maxillary, or sphenoid bones, which communicate with the nasal cavity.

**Synonyms:** - Accessory Sinus - Accessory Sinuses - Accessory sinus, NOS - Accessory sinuses - Nasal Sinus - Nasal Sinuses - Nasal and Sinuses - PARANASAL SINUS - Paranasal Sinuses - Paranasal Sinuses - Paranasal sinuses - Sinuses, Nasal - Sinuses, Paranasal - paranasal sinus - paranasal sinus