Long-term follow-up of two sisters with opposite responses to early treatment of familial Class III malocclusion

Despite the known positive effects of early orthopedic intervention in children with developing Class III malocclusions, uncertainty remains on its effectiveness and long-term benefits. In this case report, the effects of early facemask treatment followed by fixed orthodontic intervention in early permanent dentition were compared in two sisters who had a familial Class III pattern over 20 years. Facial and dental changes at various treatment phases and long-term follow-ups were recorded. The pubertal and postpubertal growth patterns and long-term outcomes between the sisters were different, although the treatment protocols were similar. One patient required orthognathic surgery at a later stage, and her sister maintained the positive early treatment changes. These observations underscore the difficulty of accurate facial prediction in the individual patient, warranting extensive research.