MANDIBULAR SKELETAL CHANGES INDUCED BY EARLY FUNCTIONAL TREATMENT OF CLASS-III MALOCCLUSION - A SUPERIMPOSITION STUDY

A superimposition study on mandibular stable structures was performed to evaluate changes in mandibular rotation and in the direction of con dylar growth induced by early treatment of Class III malocclusion by a functional appliance (removable mandibular retractor). A sample of 18 children with treated Class III malocclusions, mean age at the first observation (immediately before the beginning of treatment) 5.47 +/- 1 .14 years, mean age at the second observation 8 +/- 1.29 years, mean o bservation period 2.5 +/- 0.9 years, was compared with a control group of 18 children with untreated Class III malocclusions, mean age at th e first observation 5.72 +/- 1.11 years, mean age at the second observ ation 7.86 +/- 1.44 years, mean observation period 2.27 +/- 0.92 years . No statistically significant difference between the two groups was r ecorded for positional (total) rotation of the mandible. A significant upward-forward direction of condylar growth was assessed in the treat ed group (p < 0.001). This therapeutically induced change in growth di rection of the mandibular condyle was considered a skeletal sign of an terior morphogenetic rotation of the mandible, i.e., a mechanism compe nsating for excessive mandibular growth.