OBJECTIVETo analyze the practical effect of distalization of lower cuspiud by light-segmented archwire.

METHODS17 cases were selected. In all cases, two lower first bicuspids were extracted and lower molars were designed as reinforced anchorage. In the first half year, lower cuspids were distalized with light-segmented archwire, and lower incisors were in the physiologic drift stage. Before the treatment, three months and six months after the treatment, cephalograms and study models were recorded respectively. The data were analyzed with SPSS 10.0.

RESULTSThe distance of mesiolization of the first lower molar was 1.14 mm in half a year. The distance of distalization of the lower cuspid was 5.02 mm in half a year. No significant difference was found in LM-MP and SN-MP angle. LI-NB angle was decreased by 9.57 degrees. Crowding of lower incisors was transferred from -2.55 mm to 1.08 mm.

CONCLUSIONDuring distalization of lower cuspid by light-segmented archwire, anchorage tooth was stable, lower cuspids were distalized effectively, and lower incisors drifted towards the ideal position automatically.