ABSTRACT
The purpose of this study was to investigate the changes in the craniofacial skeleton subsequent to chincap therapy in the juvenile skeletal Class III malocclusion with more appropriate control samples. The experimental group consisted of 29 Korean children(14 males, 15 females) who had skeletal Class III malocclusion with prognathic mandible and were undergone chincap theray from the beginning of treatment. The control. group was composed of 21 Korean children(10 males, 11 females) who had no orthodontic treatment, but with similar skeletal discrepancies to experimental group. Lateral cephalometric radiographs at the age of 7, and 2 years later were analyized and compared with student's t-test(p< 0.05). The results of this study were as follows; 1. The control group without chincap therapy had not shown any improvement of the skeletal discrepancies, but had grown to be much severe. This means that the untreated Class III patient with prognathic mandible would not be corrected by growth For the experimental group with chincap therapy, the anterior-posterior skeletal discrepancies and mandibular prognathism were both improved. 2. Neither significant restraint nor acceleration of growth was found in the cranial base and maxilla by chincap treatment" The inhibition of mandibular growth could not be accepted, but the changes of the direction of growth and morphological changes were found. 4. Vertical growth tendency was increased with chincaP therapy. 5, When putting together the results of the analyses , it seems to be the rotation and displacement of the mandible that the major treatment effects of chincap are. The changes of the direction of growth and the morphological changes also seems to contibute to the treatment effect partly. In summary, the chincap doesn't restrain the mandbbular growth. But, it is considered as a useful treatment modality for correction of skeletal discrepancies and reduction of mandbbnlar prognathism in growing Class Ill patients with madibular prognathism.