[Soft tissue profile changes by Frankel-III appliance on correcting Angle Class III malocclusion in mixed dentition].

PURPOSE: The purpose of this study was to evaluate the soft tissue profile changes of functional Angle Class III malocclusion in mixed dentition, and to evaluate the effectiveness of treatment with Frankel-III appliances.

METHODS

Fifteen cases of Angle Class III malocclusion in mixed dentition, 8 males and 7 females, were selected. The mean age of the patients was 9.5 years old, ranging from 7 to 12 years old. Lateral cephalometric radiograph was taken before and after the treatments and analyzed. The data was analyzed by paired t test with SPSS17.0 software package.

RESULTS

After the patients were treated with Frankel-III appliances in mixed dentition, Sn-Ns-Si, Ns-Sn-Pos , LiSi-Sn increased, S-Ns-Si, S-Ns-Pos,LL-EP decreased with significant difference (P<0.01). S-Ns-Sn, LsSn-Sn,Sn-Me,Ns-Me,Ul-EP increased with significant difference (P<0.05).

CONCLUSIONS

All findings indicate that functional Angle Class III malocclusion can be corrected with Frankel-III appliances. The relationship among nose, upper lip, lower lip and chin become harmonious after treatment. The maxillary and mandibular soft tissue changes are distinct and soft tissue profile changes from Class III to Class I.