RESUMEN
<p><b>OBJECTIVE</b>To study the clinical effectiveness of implanting miniscrew serving as anchorage instead of molars in treating maxillary dental arch crowding and protrusive patients mandibular molars complete missing.</p><p><b>METHODS</b>Eight adult patients aged from 22 to 38, whose maxillary dental arch were crowding and protrusion, with mandibular molars missing were chosed. At the missing side, a miniscrew was implanted on the buccal surface, 11-13 mm away from the distal end of the second premolar. After implanting, a self-made miniscrew traction cap was attached to its supergingival section by keyway retention. Premolars and anterior teeth were tracted in turn to distal end. Intermaxillary traction II was made necessarily on the traction cap.</p><p><b>RESULTS</b>Successful results were acquired after treating together with normal overbite, overjet and right occlusion relation. It took 24 months in the longest course, 15 months in the shortest course and 20.8 months on average.</p><p><b>CONCLUSION</b>The implanting miniscrew anchorages could be used in maxillary dental arch crowding and protrusive patients with single molars complete missing.</p>