A Deceiving Massive Opacification of the Maxillary Sinus: Odontogenic Cyst Mimicking Odontogenic Sinusitis.

Considered the second most common type of odontogenic cysts, dentigerous cysts (DCs) are developmental lesions most often detected incidentally on radiographic imaging. The pathogenesis of DCs is not fully understood, but they are widely regarded as developmental cysts originating from the dental follicle. Although typically asymptomatic, DCs may cause clinical symptoms when they reach large sizes or get infected. This case highlights how a DC (common developmental odontogenic lesion often incidentally detected on imaging) may present with complete maxillary sinus opacification despite minimal symptoms and normal endoscopic findings, underscoring the need for precise terminology when classifying odontogenic-related sinonasal conditions.