Maxillary sinus hypoplasia, embryology, and radiology.

Maxillary sinus hypoplasia has been observed in up to 10% of radiological studies of the face or head. Although this may be a coincidental finding, it has been associated with chronic sinusitis and facial pain. Associated abnormalities of the lateral nasal wall, orbit, and ostiomeatal complex are common. The importance of this condition is, first, in the differential diagnosis of an "opaque" maxillary sinus and, second, as a potential hazard to the orbit of such patients, should they undergo functional endoscopic sinus surgery.