[A study on the combination of Nance arch and TPA in the use of straight-wire arch orthodontic treatment].

Purpose: To evaluate the effect of combination of Nance and TPA on the use of MBT appliance to treat Class II division I malocclusion.

Methods: Nineteen cases of Class II division I malocclusion, aged from 12 to 16 years, underwent Nance arch and TPA in the use of MBT appliance to reinforce molar anchorage. Cephalometric analysis and model measurements were conducted and compared before and after treatment using SAS8.

[Dental arch form reverting by four-point method].

Purpose: To explore a simple method of reverting individual dental arch form template for wire bending.

Methods: Individual dental arch form was reverted by four-point method. By defining central point of bracket on bilateral lower second premolar and first molar, certain individual dental arch form could be generated.

[Preliminary clinical study on intrusion of overerupted molars with a removable appliance].

Purpose: To evaluate the clinical effect of molar intrusion with a removable appliance and determine its clinical value.

Methods: Seven patients were selected in the study.The clinical effect of intrusion was evaluated,the periodontal attachments and root resorption post-treatment were accessed by models,clinical examination, periapical radiograph analysis via CygnusRay2TM digital X-ray system pre and post-treatment.