Pathological fracture of the mandible caused by radicular cyst: A case report and literature review.

RATIONALE: Pathological fracture of the mandible caused by radicular cyst is rare. This report describes a unique case of a mandibular pathological fracture caused by radicular cyst, arising from an endodontically treated molar. PATIENT CONCERN: A 49-year-old female was referred to our department with persistent pain in left mandibular angle, accompanying with restricted mouth opening and malocclusion. DIAGNOSE: An orthopantomograph (OPG) showed a unilocular lesion with a relatively well-defined border, and the lesion was associated with a fracture in the inferior border of the mandible. INTERVENTION: This patient was treated through curettage of the cyst combined with open reduction and internal fixation of the fracture. OUTCOMES: At the 1-year follow-up visit, the patient did not have any complaints, and the radiographs indicated the consolidation of the fracture without recurrence of cyst. LESSONS: This case report highlights the routine follow-up of endodontically treated teeth in order to check for apical healing and detect the cystic change at early stages.