RESUMEN
After a diagnostic study involving computer tomography and bone scintigraphy, a 16-year-old boy appeared to be suffering from the monostotic type of fibrous dysplasia of the maxilla. The diagnosis was confirmed by histopathological examination ofa biopsy. During a follow-up period of 8 years, no signs of progression were evident. Fibrous dysplasia is a rather poorly understood benign bone disease which may occur anywhere in the skeleton. In general, histopathological confirmation using a bone biopsy is recommended. Fibrous dysplasia can be divided into 3 types: 1. monostotic, 2. polyostotic, and 3. polyostotic with endocrine problems. In the majority of cases, a wait-and-watch strategy is sufficient. Malignant transformation is extremely rare and appears almost exclusively in polyostotic cases.