Many diseases of the maxillofacial complex are localized, whereas others are manifestations of systemic or multisystem diseases. Regardless of their pathogenesis, diseases that affect teeth, bones, oral mucosa and salivary tissues result in clinically observable tissue changes that subsume many processes. Some diseases that arise central in the jaws are, in fact, odontogenic, while others do not involve the odontogenic tissues. Rather, they affect the osseous and marrow elements, much the same as diseases that arise in other areas of the skeleton. Some jaw lesions are symptomatic, some merely cause expansion or enlargement of the maxillofacial bones and yet others are detectable only on radiographs or other imaging systems. Because radiographs are routinely taken for dental diagnostics, most central jaw lesions are identifiable on the basis of radiography. Central jaw and sinus lesions are, therefore, classifiable according to radiographic features.