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Quantitative Assessment Protocol for Facial Soft Tissue Volumetric Changes with Stereophotogrammetry
Published on: December 9, 2025
[Changes of hard tissues in patients with functional and skeletal Angel Class Ⅲ malocclusion after FRⅢ appliance
Nan Zhang1, Sun Wang, Wei Zheng
1.Department of Stomatology, First Affiliated Hospital of the Medical School, Shihezi University. Shihezi 832008, Xinjiang Uygur Autonomous Region, China.
Purpose:
To compare changes of hard tissues before and after treatment of functional and skeletal Angle Class Ⅲ malocclusion with FRⅢ appliance.
Methods:
Thirty patients with functional and skeletal Angel Class Ⅲ malocclusion were selected and treated with FRⅢ appliance. SPSS 22.0 software package was performed for statistical analysis.
Results:
After treatment, there was no significant difference in SNA, S-Ptm, ANS-Ptm and Go-Po (P>0.05). ANB, ANS-Me, ANS-Me /N-Me were increased significantly (P<0.01). SNB, L1-NB, L1-MP were decreased significantly (P<0.05). MP-FH, Y axis, U1-NA, U1-NA (mm), U1-SN were increased significantly (P<0.05).
Conclusions:
After FRⅢ appliance treatment of Angel Class Ⅲ malocclusion, the position of mandible may rotate clockwise downward and backward, with retrusion of the lower incisors and protrusion of the upper incisors.

