Abstract: Abstract Objective：To investigate the clinical effect of micro-screws with rocking-chair archwire in treatment of Bi-maxillary dental protrusion. Methods: A total of 12 cases of Bi-maxillary dental protrusion patients with removal of four first premolars were chosen。The cases were treated with micro-screws and rocking-chair archwire .Cephalometric indicators changes before and after treatment were compared. Results: 12 patients were successful treated, Incisors retracted significantly :U1-SN mean reduced 12.92°,U1-NA mean reduced 12.92°,U1-NA (mm) mean reduced 5.90mm, L1-MP mean reducted12.75°,L1-NB mean reducted of 9.98°,L1-NB (mm) mean reduction 5.19mm ;Soft tissue profile improved significantly:NLA mean reduced 11.39°,EP-UL mean reduced 3.58mm, EP-LL mean reduced 3.78mm; MPA、OP-FH increased not significantly. Conclusion: Micro-implant anchorage with rocking-chair archwire can effectively treat Bi-maxillary dental protrusion.

Key words: micro-screws, rocking-chair archwire, Bi-maxillary dental protrusion