Related Experiment Video
Updated: Jun 4, 2026
Quantitative Assessment Protocol for Facial Soft Tissue Volumetric Changes with Stereophotogrammetry
Published on: December 9, 2025
[Hard and soft tissue changes following the treatment of Class II division 1 malocclusion using twin-block appliance]
Li-Guo Li1, Yan-Ping Zuo, Dong-Hui Yuan
1Dept. of Stomatology, The Bethune International Peace Hospital, Shijiazhuang 050082, China.
Objective:
To investigate the hard and soft tissue changes following the treatment of Class II division 1 malocclusion using Twin-block appliance.
Methods:
50 Class II division 1 malocclusion subjects whose handwrist radiographs were in FG-G stage were selected. One group (27 patients) was treated with Twin-block appliance, the other group (23 patients) was observed without treatment The acquired data of cephalometric of two groups were analyzed statistically with SPSS 11.0.
Results:
Soft tissue changes, Ls-E, Li-E, U1-Stms, Stms-Stmi, NsLs-FH, LsNsLi, LsNsPg', the angle of H decreased. Sn-Stms, Stmi-Me', Ns-Me', Sn-Me', NsLi-FH, NsPg'-FH, A'Ls-FH, B'Li-FH, LiB' Pg', CmSnLs, GSnPg', the angle of Z increased, there was statistically significant difference (P < 0.05). Hard tissue changes, SNB, L1-NB, IMPA increased, ANB, U1-SN, U1-NA, FMIA decreased, there was statistically significant difference (P < 0.05).
Conclusion:
Sagittal relationship between upper- and lower-jaws is effectively improved after orthopedics with Twin-block appliance. Lower face height increases. Soft tissue profile tends to be straight-styled.
