The term "fistula" can be defined as an improper connection between different body compartments. It can occur in different parts of the body. Although, fistulae mostly develop due to untreated chronic infections, traumatic injuries and congenital deformities, specific infections or diseases, and post-surgical healing abnormalities can also cause fistula formation. Although, there is a general classification system made by the World Health Organization to identify fistulae, specifically, in this chapter oral fistulae are divided into four different categories, namely dentoalveolar, oroantral, oronasal and orocutaneous fistulae. The diagnosis and the treatment protocols for oral fistulas are described using this specific classification and with additional new techniques introduced for the correction of the lesions. Conventional surgical methods also are summarized. The importance of the radiological examination is emphasized and the practitioners are informed of possible complications.

Nasopalatine duct cyst is the most common non-odontogenic cyst. It develops in the midline of the anterior maxilla. It is usually asymptomatic and sometimes it can be overlooked or misdiagnosed. We present 10 patients who applied to Istanbul University Faculty of Dentistry, Department of Oral and Maxillofacial Surgery.