[The fabrication and clinical application of semi-fixed mandibular lingual arch expansion appliance].

Semi-fixed mandibular lingual arch expansion appliance is composed of a mandibular molar band, a keyway and arch expansion spring. The arch expansion spring are used to expand maxillary arch symmetrically or asymmetrically when bolts of the two ends are inset into keyways. Dental arch expansion appliance for 25 patients with mandibular arch stenosis showed that semi-fixed mandibular lingual arch expansion had good effect and could be used to expand mandibular arch.

[Series orthodontic treatment on teeth transposition of maxillary canine and lateral incisor].

OBJECTIVE: To explore the treatment on teeth transposition of maxillary canine and lateral incisor in order to improve the clinical treatment effect. METHODS: Eleven patients with transposition maxillary canine and lateral incisor were treated with the method: Expand space, artificial reverse occlusion of transpositional lateral incisor to give way, transpositional lateral canine distalization and controlling root, mesial movement of lateral incisor with tongue arch, interactive controlling roots and retention with tongue fixed retaining appliance. RESULTS: Eleven patients had satisfactory treatment effect, with tidy dentition and parallel teeth roots of transpositional canine and lateral incisor. CONCLUSION: Series orthodontic treatment on teeth transposition of maxillary canine and lateral incisor can effectively improve the clinical treatment effect and shorten the treatment time.

[Treating maxillary dental arch crowding and protrusion of the patient with mandibular molars missing by implanting miniscrew anchorage].

OBJECTIVE: 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. METHODS: 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. RESULTS: 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. CONCLUSION: The implanting miniscrew anchorages could be used in maxillary dental arch crowding and protrusive patients with single molars complete missing.