[Comparison between J-hook and micro-implant anchorage in the treatment of patients with bimaxillary protrusion].

Objective: To compare the difference between J-hook and micro-implant anchorage in the treatment of patient with bimaxillary protrusion.

Methods: Thirty patients with bimaxillary protrusion were divided into two groups (J-hook and micro-implant groups) and treated with MBT appliance. Four first premolars were extracted in all patients. Cephalometric analyses were carried out before and after treatment.

Results: In J-hook group and micro-implant group,computerized cephalometric analysis revealed that before treatment U6C-PP was (12.4 +/- 0.2) mm and (12.5 +/- 0.1) mm, respectively,and after treatment U6C-PP was (12.6 +/- 0.1) mm and (12.8 +/- 0.1) mm,respectively. The difference between J-hook group and microimplant group was significant (P < 0.01). The other differences of cephalometric analyses between J-hook group and micro-implant group was not significant.

Conclusions: Both J-hook and micro-implant could provide adequate anchorage in the treatment of patients with bimaxillary protrusion.