A 19-year-old experiences pain over her cheeks and discolored nasal discharge. Which sinus do you suspect is affected?

The symptoms described – pain over the cheeks and discolored nasal discharge – point to an involvement of the maxillary sinus. The maxillary sinuses are located in the cheeks, and irritation or inflammation in this area typically results in pain that manifests in the cheek region. Additionally, sinus infections often lead to nasal discharge that may be discolored due to the presence of infection or inflammation; this can occur with maxillary sinusitis.

The other sinuses, while they can also contribute to sinus-related pain and discharge, are located in different regions. For example, the ethmoid sinus is situated between the nasal cavity and the orbit (eye socket) and would generally cause pain around the eyes or bridge of the nose. The sphenoid sinus is deeper in the skull and may contribute to pain at the back of the head and discomfort around the eyes, but it is less likely to be directly associated with facial pain in the cheek area. The frontal sinus, located in the forehead region, typically presents with forehead pain rather than cheek pain.

Thus, given the specific symptom of cheek pain combined with the discolored nasal discharge, the maxillary sinus is the most likely sinus to be affected in this scenario.