Abstract: PURPOSE: To study the clinical effect of the upper first molar space closure by mesial traction of the second and the third molar with palatal miniscrew and casting frame. METHODS: Twelve cases with the upper first molar lost and only accepting regional orthodontic treatment were chosen. Two miniscrews were inserted beside the palatal suture, individual casting frames were manufactured to help stabilize the miniscrew and the upper premolars on the same side. The force was exerted on both the buccal and lingual side. Graphpad Prism 6.0 software was used for Student's t test. RESULTS: All the spaces were closed, the average mesial movement was 5.7 mm, the tipping of the second molar and the third molar was almost normal and the occlusion of other teeth kept intact. CONCLUSIONS: Miniscrew and casting frame can accomplish the effective mesial movement of the upper second and third molar to close the first molar space.

Key words: Miniscrew, Casting frame, Space closure