Long-term treatment effects of the FR-2 appliance of Fränkel.

INTRODUCTION: The objective of this study was to evaluate the long-term effectiveness in a group treated with the FR-2 appliance of Fränkel compared with an untreated Class II control group.

METHODS: The sample consisted of 30 patients (17 boys, 13 girls) treated exclusively with the FR-2 by Rolf Fränkel. The mean age at the start of treatment was 8 years (T1), with a posttreatment cephalogram (T2) taken 10 years later. The control group included 20 subjects (11 boys, 9 girls) with untreated Class II malocclusion. Their mean ages at T1 and T2, and the mean times of observation, matched the treatment group closely. Lateral cephalograms were analyzed with a specific tracing regimen at both T1 and T2 in both groups. The Student t test was used to compare changes between the groups

RESULTS: The FR-2 group maintained stable correction of the initial Class II malocclusion over the evaluation period. Significant mandibular and intermaxillary changes and dentoalveolar changes were noted in the treated group, with a 3-mm long-term increase in mandibular length compared with the untreated Class II controls.

CONCLUSIONS: This study suggests that correction of a Class II malocclusion with the FR-2 appliance maintains favorable results over the long term with both skeletal and dentoalveolar changes.