Skeletal and dental effects produced by functional regulator-2 in pre-pubertal class II patients: a controlled study

Abstract

Background: Whether skeletal effects are obtained by functional appliances in class II subjects is still controversial. In this regard, most of the available studies did not clearly identify the growth phases (i.e. pubertal or not) of the treated patients. This retrospective controlled study aimed at evaluating the skeletal and dental changes in class II subjects produced by the functional regulator (FR)-2 treatment during the pre-pubertal growth phase.

Methods: The data were derived from records obtained at a university dental clinic. A total of 17 treated subjects and a total of 17 untreated controls, all pre-pubertal, matched for malocclusion, age (8.8±1.5 years) and sex (18 females, 16 males), were included. The overall observational period was 1.6±0.8 years for both groups.

Results: Only minor skeletal changes with very little clinical relevance were seen after the observational period. Most of the changes produced by the FR-2 treatment were at the dental level including palatal tipping of the maxillary incisors and slight proclination of the mandibular incisors, both accounting for the noteworthy overjet reduction.

Conclusions: The present study has shown that functional treatment of class II malocclusion by FR-2 appliance during the pre-pubertal growth phase is limited to modification at the dental level.

Figure 1

Landmarks, distances and planes used in the chephalometric analysis. Planes of reference: FH, Frankfurt horizontal plane; NL, nasal line; ML, mandibular line; FOP, functional occlusal plane; N perp, line on N perpendicular to the FH.

Figure 2

Treatment effects on main sagittal skeletal parameters. Treatment effects refer to the difference in mean changes between the time points of the treated and untreated control groups. None of the mean values reported (+0.5 mm (Co-A), +0.1 mm (Co-Gn), −0.3 mm (A to N perp) and +0.6 mm (Pg to N perp)) were in the range of the method error and not statically significant when expressed as effect size coefficient.