When assessing the maxillary sinuses for tenderness, which action should the nurse take?

The maxillary sinuses are air-filled cavities located within the maxillary bones beneath the orbit and lateral to the nasal cavity. Inflammation such as sinusitis causes mucosal edema and increased pressure, making the sinus walls tender to palpation during physical examination. Rationale: A. Eyebrow ridges are anatomical landmarks overlying the frontal sinuses, not the maxillary sinuses. Palpating this area assesses frontal sinus tenderness, so this technique does not evaluate the maxillary sinuses accurately. B. Transillumination below the browbone is used to assess frontal sinus aeration and fluid presence. This method does not evaluate maxillary sinus tenderness and is not appropriate for detecting maxillary sinus inflammation. C. Cheekbones (maxilla) are the correct anatomical location for maxillary sinuses. Applying gentle firm pressure here directly assesses maxillary sinus tenderness, which is a key clinical sign of sinusitis affecting these structures. D. Nasal airflow occlusion testing assesses patency of nasal passages and possible obstruction but does not evaluate sinus tenderness. It is unrelated to maxillary sinus palpation and does not identify inflammation in sinus cavities.