Facial swelling is a common presenting sign of the dental emergency patient. The most common etiology of the swelling is odontogenic infection, whereupon the dental practitioner begins his intraoral examination in order to assess, diagnose and ultimately treat the source of the swelling. In many cases the examination is academic, as the causative tooth sticks out like the proverbial 'sore thumb.' Other times the source of the swelling is not so clear cut, and the practitioner must formulate a differential diagnosis in order to accurately deal with the pathology. It is vital that all information be accurately assessed prior to diagnosis and treatment. The etiology of facial swelling may be infectious, traumatic or neoplastic.