A retrospective analysis of growth of the constructed condyle-ramus in children with hemifacial microsomia.

A retrospective analysis of changes in costochondral rib grafts used to construct the condyle-ramus in children with hemifacial microsomia (HFM) was made. The mean age at surgical correction was 6.5 years, and the average follow-up was 4.5 years. Direct measurements were made on panoramic radiographs. The condyle-ramus length was expressed as a percentage change comparing the constructed with the normal side. During the first 2 postoperative years, there was either no change or a slight decrease in the length of the rib graft. After 2 years, however, the costochondral graft elongated at a slow, irregular rate. The mode change was 11 percent over the postoperative study period. In four patients who exhibited rapid growth of the normal condyleramus (greater than the mean change of 0.94 cm), the constructed side failed to keep pace. In another group of four patients who exhibited moderate elongation of the normal side, the grafted side grew commensurately or demonstrated greater than normal percentage change in length. There was no correlation between the initial size of the costochondral graft, age at time of operation, or presenting type of mandibular deformity. These findings are discussed in terms of the intrinsic growth and the functional matrix theories of mandibular development.