Abstract:

Obsjective

To investigate clinical application of orthodontic magnetic appliances made with the thermoplastic material and polymethyl methacrylate plastics.

Methods

Eighteen anterior crossbite patient cases were selected and divided into polymethyl methacrylate plastics group （group A）and thermoplastic materials （group B）， with nine patients for each group. The two groups were observed for: （1）the fabricating time and chair time； （2）patients' subjective feeling of wearing the appliances；（3）treatment outcome after 1 year； and （4）emergency visit times.

Results

The fabricating and chair time in Group B was （19.44 ± 6.44） min and （3.11 ± 1.27） min， respectively， which was shorter than group A （P＜0.05）. The subjective feeling in group B was better than in group A （P＜0.05）. During the year of treatment， the times of emergency visiting were more in Group A （P＜0.05）.

Conclusions

The orthodontic magnetic appliance made of thermoplastics showed remarkable superiority in fabricating and clinical chair time， patient's subjective feeling and durability over the one made of polymethyl methacrylate plastics. It suggests to use the orthodontic magnetic appliance made of thermoplastics in clinical application.

Key words: Thermoplastic materials, Polymethyl methacrylate plastics, Magnetic, Appliance, Clinical study