Patients often present to their dental providers with reports of posterior maxillary pain. The etiology of their symptoms may be either an acute or chronic situation, and the examining dentist's primary focus is usually to rule out dental pathosis. Rhinosinusitis should be an important consideration on the list of differential diagnoses when evaluating patients with posterior maxillary pain. The American Academy of Otolaryngology standardized the terminology for paranasal sinus infections in 1996 and offered guidelines for evaluation and treatment of sinusitis. This article highlights these guidelines for diagnosing and treating patients with rhinosinusitis. It also includes a review of sinus anatomy and of the special considerations for iatrogenic sinus exposure as well. Dental providers who understand the relationship between the maxillary sinus and the oral structures are better prepared to arrive at an accurate diagnosis. The astute dental provider will ensure a rapid and positive outcome for this group of patients with rhinosinusitis.