OBJECTIVETo offer some reference for micro-implant's development and population by analyzing clinical application of two kinds of micro-implant systems.

METHODS38 patients treated with MIA (micro-implant anchorage) and 28 patients treated with SDIA (self-driven titanium implant for orthodontic anchorage) were included. Analyzing the rate of lost implants, the gum's reactivity and the efficiency of moving teeth summarized the excellences and shortcomings of two systems.

RESULTS1) Six of MIA implants fell off after being inserted. Seven of SDIA implants lost when they had been implanted for a month. But they were stable after being inserted again. 2) The gum around 12 SDIA implants got inflammation symptom, but the gum around MIA implants was normal. 3) Both MIA implants and SDIA implants could move teeth effectively and persistently when they were stable.

CONCLUSIONWhen we apply micro-implant in clinic, we should prevent it from closing roots of teeth and choose the small tip micro-implant. The embedded position should be in area of attachment gum. At the same time, the areas around the tip of micro-implant should be keeping clean.