[Chronic maxillary atelectasis: an uncommon cause of persistent radiological opacification].

Chronic maxillary atelectasis (CMA) is an infrequent entity characterized by a persistent decrease in maxillary sinus volume due to inward bowing of one or more antral walls. The cause of CMA is probably maxillary sinus hypoventilation secondary to ostiomeatal complex obstruction. This creates negative pressure, leading to thinning of the sinus walls. We report the case of a 14-year-old asymptomatic girl with an opacified maxillary sinus on radiology following unsuccessful antibiotic treatment. A coronal computed tomography scan showed partial right antral opacification, with a laterally malpositioned medial infundibular wall and fontanel retraction, and consequently CMA was diagnosed. The interest of this case lies in the infrequency of CMA and the need to distinguish it from maxillary sinusitis.