Fibrous dysplasia is a rare disease, a slowly progressive benign pseudotumoral osteopathy, characterized by a proliferation of connective fibrous tissue that replaces the medullary bone with trabeculated bone. It affects mainly the skull, the maxillofacial region and the long bones. It is a congenital and metabolic disorder. We present the case of a 20-year-old female patient from Tanzania, with a history of good health, who presented to the department of maxillofacial surgery of the Kitui Country Referral Hospital, Kenia, due to an abnormal and deforming growth in the lower third of the face, with more than six years of progress. She reported difficulty speaking, pain while eating hard food and having had repeated infectious processes. On intraoral examination a displacement of the left dental structures was found, as well as bleeding and reddened mucus with indentations resulted from the trauma caused by the upper teeth on the tumoral surface. She had a bad oral hygiene, halitosis and a curvature of the tongue and of the structures of the floor of the mouth towards the opposing side. CT scan showed an expansible image, with intralesional calcifications, that occupied the whole left mandibular region. A preoperative incisional biopsy was performed, which showed a mandibular fibrous dysplasia. Exeresis of the tumoral mass was performed with the placement of a titanium plate, restoring the lost mandibular bone and thus securing the space for future bone reconstructions. The early diagnosis of this condition would avoid aggressive procedures, making it possible to preserve the possible greatest amount of healthy bone.La displasia fibrosa se define como una osteopatía pseudotumoral benigna de lenta progresión, caracterizada por una proliferación de tejido fibroso conectivo que reemplaza el hueso medular por hueso trabeculado. Puede aparecer en cualquier parte del cuerpo, principalmente afecta cráneo, región maxilofacial y huesos largos. Es una alteración congénita y metabólica, que a veces se asocia con pigmentaciones cutáneas o anomalías endocrinas, por lo que es necesario una comprensión completa de la naturaleza de esta enfermedad y su curso clínico, para optimizar el manejo quirúrgico de pacientes tan afectados. En este estudio, se describe un caso clínico, tratado en el hospital de Kitui, Kenia, en el servicio de Cirugía Maxilofacial, donde una paciente femenina de 20 años de edad, raza negra, procedente de Tanzania, es remitida por presentar un aumento de volumen considerable en la región mandibular izquierda, de larga evolución, afectándole la estética, el habla y la masticación. Luego de examinada, se determinó hacer una biopsia incisional preoperatoria, mostrando como resultado una displasia fibrosa mandibular. Se procede a la excéresis de la masa tumoral y la colocación de una placa de titanio restituyendo el hueso mandibular perdido, asegurando de esta manera el espacio para futuras reconstrucciones óseas
