&NA;Hemimandibular hyperplasia is a well‐defined, rare asymmetrical mandibular malformation. It is characterized by diffuse enlargement of the condyle, the condylar neck, and the ramus and body of the mandible. Because the anomaly begins before puberty, it is understandable that the maxilla follows the downward growth of the mandible. Pathogenesis is due most likely to clear hyperactivity in the condyle, which can be documented histologically with an actively proliferating cartilage. Therapy is largely based on the patient's age. The authors present their series of nine individuals with hemimandibular hyperplasia treated with various surgical methods between 1992 and 1994. A therapeutic approach calledorthopedic maxillary managementapplied to two of the nine patients is presented. The objective is to maintain the occlusal maxillary plane in a correct position in growing patients. All clinical results, except one, were satisfying and showed good postoperative stability.