The effect of treatment with functional appliance on a pathologic growth pattern of the condyle.

Hemifacial microsomia causes asymmetry of the face frequently known to progress throughout the postnatal development if not submitted to any kind of treatment. According to the theoretic basis for treatment of hemifacial microsomia as presented by Harvold and associates, generation of the right muscle-bone interaction constitutes the necessary precondition for the bone apposition that produces facial symmetry. This theory was the basis for the treatment of three patients with abnormal condyles, one suffering from hemifacial microsomia, one patient with a unilateral condylar fracture followed by displacement and secondary resorption of the condyle, and one patient with bilateral loss of condylar cartilage as a result of trauma. The patients were treated with an activator a.m. Harvold, and the treatment results analyzed radiographically and clinically. The results demonstrated clearly that generation of an altered muscle balance is possible even though hemifacial microsomia patients suffer from absence of normal muscles--that is, normal functional matrix as well as absence of normal condyle--and that bone apposition required for establishment of symmetry can be achieved if the right microenvironment is established. It was, however, also obvious that treatment should be initiated as early as possible because the treatment result was dependent on both the timing and the cooperation of the patient.