Background: This study evaluated three-dimensionally the skeletal effects of two different intraoral force application systems for treating skeletally growing ClassIII patients(RCT).
Methods: Thirty-three patients were recruited for this study and randomly allocated between three groups: GroupI(n=11)patients treated with CS2000(CSgroup/pulling force) GroupII(n=11)patients treated with reversed Forsus Fatigue Resistant(RFgroup/pushing force) and GroupIII(n=11)untreated control group(negative control). CBCT image was taken before treatment(T0) and after gaining a 2mm overjet or after an observation period of six months(T1). Skeletal measurements were assessed and compared between the two groups. Within group comparisons were done using Wilcoxon Sign Rank test.
Results: Sagittally in RF group, OLp-Apt increased by3.60mm, OLp- Bpt decreased by-2.50mm and OLp-Pg decreased as well by-2.00mm(P<0.0001). While in CSgroup, OLp- Apt increased by3.10mm, OLp-Bpt decreased by-1.10mm and OLp-Pg decreased as well by-1.00mm(P<0.0001). Wits appraisal increased by5.00mm and5.50mm in RF and CS group accordingly after treatment(P<0.0001). There was an increase in OLs-Apt in both treatment groups by3.80mm in RFgroup and 5.00mm in CSgroup(P<0.0001). Vertically there was a statistical significant difference between two groups. ANS-Me decreased in RFgroup by-0.70mm and increased in CSgroup by2.00 mm. Both treatment groups demonstrated an increase in the SNA angle(2.6° in RF group and2.5° in CSgroup)(P<0.0001), a decrease in the SNB angle-1.00° in RFgroup and-2.00° in CSgroup(P<0.0001), hence increase ANB angle.
Conclusions: CS2000 spring and reversed Forsus Fatigue Resistance device both promoted forward maxillary advancement in an average of 5months. Both appliances gave close effects to bone anchored maxillary protraction devices and functional appliances, removing compliance factor out of the equation.