Compacting Mandibular Molar by Using Micro-implant Anchorage:A Clinical Study

Objective To evaluate clinical effects and the features by micro-implant anchorage in compacting mandibular molars in Angle ClassⅠmalocclusion. Methods Twenty-four micro-implants were embedded mesial and distal bone of mandibular first molar of 12 Angle Class Ⅰ malocclusion patients as clinical anchorages for compacting mandibular molars. The position changes of mandibular molars from compaction and the buccolingual position and mesiodistal inclination were measured and the compacting velocity,root obsorbsion and periodontal membrane change were observed. The anchorage was evaluated by the change of mandibular second molar and mandibular central incisor. Results The compaction was 3.5mm,the course of treatment was 5.2months,the velocity of mandibular first molar compacting was 0.67 mm per month and the buccall movement of mesial and the distal cusp were 1.2mm and 1.3mm,with no root absorption and periodontal membrane change and with no change in the location of mandibular second molar and mandibular central incisor. Conclusion The method can successfully compact mandibular molars to appropriate positions,providing enough space for antagonizative maxillary first molar restoration. And meantime,it is easy and convenient in the clinical application,worthy of being popularized.