[Solitary bone cyst of the mandible and platelet rich fibrin (PRF)]. / Kyste osseux solitaire de la mandibule et fibrine riche en plaquettes (PRF).

INTRODUCTION: Solitary maxillary or mandibular bone cysts are rare benign lesions. They are usually localized in the mandible of young men. In some cases, a traumatic risk factor can be documented. OBSERVATION: A young 13-year-old female patient consulted in the orthodontics unit. An orthopantomogram showed a large cystic lesion in the ramus and posterior part of the left mandible corpus. No reossification of the cavity was observed one year after curettage. A second curettage was performed combined with PRF filling. Six months later, the cavity was completely reossified. DISCUSSION: Curettage is the first line treatment of isolated cystic lesions and generally followed by complete reossification of the cavity. Incomplete healing is observed in 20% of the cases. PRF may induce the healing of non-reossified cystic cavity by supplying local growth factors.