[Extra-osseous maxillary cysts--nasolabial cyst]

The maxillary cysts are classified on the basis of the recommendations by the World Health Organisation (1971), based on pathogenic criteria, in developmental and inflammatory, odontogenic and nonodontogenic cysts. Only two maxillary cysts lie primarily extraosseous: a non-odontogenic cyst, the nasolabial cyst, and an odontogenic cyst, the gingival cyst. The nasolabial cyst is a rare, developmental, non-odontogenic maxillary cyst, which offers the peculiarity of its constant extraosseous localization. On the basis of our cases from 1966 to 1988 the clinical patterns, histopathology, differential diagnosis, therapy, prognosis and histopathogenesis of the nasolabial cyst are presented.