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Updated: May 29, 2026

In situ Compressive Loading and Correlative Noninvasive Imaging of the Bone-periodontal Ligament-tooth Fibrous Joint
Published on: March 7, 2014
[Effect of semi-fixed Twin-block appliance on temporomandibular joint remodeling]
Fang-fang Gong1, Jing Feng, Zheng Hu
1Department of Orthodontics, Shanghai Jiao Tong University School of Medicine, Shanghai, China. fangfanggong@gmail.com
Purpose:
To evaluate quantitatively the effect of semi-fixed Twin-block appliance on the temporomandibular joint remodeling during the Class II malocclusion treatment.
Methods:
Twenty two Class II division 1 patients treated with semi-fixed Twin-block appliance were included. Pre- and post-orthopedic treatment cephalometric data were analyzed with SPSS13.0 software package for paired t test.
Results:
The mandibular condylar growth was directed superiorly(2.7mm) and posteriorly (3.6mm) (P<0.01), the glenoid fossa was displaced in a inferior(1.5mm) (P<0.01) and posterior (0.8mm)(P<0.05) direction, the effective TMJ changes showed a pattern similar to condylar growth in a superior(4.2mm) and posterior(2.7mm) direction(P<0.01), the mandibular rotation was slightly clockwise(P>0.05).
Conclusions:
The application of semi-fixed Twin-block appliance shows its effectiveness on patients' compliance and the remodeling in temporomandibular joint, contributing to the correction of sagittal jaw relationship discrepancy.

