The maxillary sinus is the paranasal sinus that impacts most on the work of the dentist as they will often be required to make a diagnosis in relation to orofacial pain that may be sinogenic in origin. Maxillary sinus disease is often coincidentally observed on radiographs, and dentists often have to make a diagnosis and plan treatment based on the interpretation of the image. This paper aims to guide the dental professional through some of the disease processes involving the paranasal sinuses and in particular the maxillary sinus. The outcome is to encourage comprehensive history taking and examination of the patient to facilitate an accurate diagnosis that will enable successful treatment.