The purpose of this study was to assess the early effect of FR III on the growing patients with anterior cross-bite. The lateral cephalograms and models were obtained from 7 patients at the time of pretreatment and correction of anterior cross-bite. The results were as follows: 1. A slight tendency of rotation toward anterosuperior direction and the growth to anterior direction were shown in maxilla. 2. There were a little change of mandibular vertical position and increase in lower facial height although some variations existed. 3. The bodily or labial tipping movement was shown in maxillary incisors. 4. The lingual tipping of mandibular incisors was shown in all cases. 5. Maxillary arch width increased while mandibular arch width usually changed a little although some variations existed. But it was difficult to summary in a word because variable responses were noted according to a wide variety of skeletal type, growth, and malocclusion.