Craniofacial changes induced by early functional treatment of Class III malocclusion

To evaluate the effects of a functional appliance (removable mandibular retractor) on the craniofacial skeleton in children with Class II malocclusions, a longitudinal cephalometric study was performed. A sample of 30 children with treated Class III malocclusions (18 boys, 12 girls, mean age at the first observation 5.64 +/- 1.01 years, mean age at the second observation 8.43 +/- 1.73 years) was compared to a sample of 30 children with untreated Class III malocclusions (13 boys, 17 girls, mean age at first observation 6.06 +/- 1.14 years, mean age at the second observation 8.45 +/- 1.79 years) used as controls. The treated group matched the control group as to sex, age at the first observation, age at the second observation, observation period, Class III occlusal signs, and also as to angular craniofacial dimensions at the first observation. A cephalometric analysis based on a stable basicranial reference system was applied. The main significant findings in the treated group were an anterior morphogenetic rotation of the mandible as a result of an upward-forward direction of condylar growth, a more vertical orientation of the ramus, and a reduced gonial angle; reduced mandibular protrusion and total length; increased maxillary protrusion; increased maxillary dentoalveolar protrusion and reduced mandibular dentoalveolar protrusion. No significant changes in the vertical craniofacial relationships and in cranial base angulation were observed. The role of an early correction of Class III occlusal relationship in the establishment of a more favorable craniofacial growth pattern was discussed.