Suspected Endodontic Failure in a Patient with Cleidocranial Dysplasia: A Case Report.

A patient's medical history and related dental manifestations can significantly contribute to confounding signs and symptoms leading to a diagnostic challenge. An 18-year-old female patient presented with persistent radiographic radiolucency associated with the apex of a previously treated tooth (tooth 9); asymptomatic apical periodontitis and endodontic failure were suspected. This report presents how a patient's condition of cleidocranial dysplasia had a profound effect on her dental history, which included the presence of multiple supernumerary teeth. Extensive surgical intervention during the patient's childhood was required to remove the supernumerary teeth, which resulted in an endodontic misdiagnosis in her adult life. After clinical and radiographic examination, the patient was diagnosed with a periapical scar. Periapical fibrous scars have a prevalence of between 2.5% and 12% and are a rare healing process with fibrous tissue after surgical and nonsurgical interventions. This report describes the diagnosis and pathophysiology of fibrous scars, including their risk factors and long-term monitoring approaches.