Facial growth during treatment with the function regulator appliance.

Facial growth was examined in ten patients who had completed one year of treatment with the function regulator 2 (FR-2) as described by Fränkel. Cephalometric headfilms taken before and one year into treatment were superimposed on stable structures in the anterior cranial base, and the qualitative changes were analyzed. The results showed that facial growth in most patients was mainly in the vertical plane, but considerable individual variations were seen. The maxilla generally became more retrognathic during treatment and showed backward rotation and posterior displacement in some patients. Marked individual variations were seen in the mandible. No indications were found that the FR-2 promoted forward growth of the mandible as used in this study (no notching of teeth and less than 5 mm of mandibular advancement). The improvement in dental occlusion observed was primarily due to changes in the vertical relationship between the jaws.