A clinical study evaluating the accuracy of teeth rotation correction with removable clear appliance

Abstract

Objective \nTo evaluate the accuracy of rotation correction for maxillary central incisor, maxillary lateral incisor, maxillary canine and maxillary premolar with removable clear appliance, and the influence of attachment design and interproximal reduction on correction efficiency. \n \n \nMethods \nThe study included 142 maxillary teeth (27 central incisors , 23 lateral incisors, 45 canines and 47 premolars ) which were designed to treat rotation with clear aligners. According to whether IPR or whether using attachments, maxillary central incisor and maxillary lateral incisor were divided into 2 groups: teeth with IPR only(IO) and teeth with no attachments no IPR(N). Maxillary canine and maxillary premolar were divided into 3 groups: teeth with attachments only(AO), IPR only(IO), with attachments and IPR(B) and no attachments no IPR(N). Pre-treatment and staged plaster cast models at time only rotation were designed were laser-scanned, and the real tooth movements were obtained by digital model superimposition. Intragroup comparisons were made using Independent-Sample T test, analysis of variance and Student-Newman-Keuls test. \n \n \nResults \nThe mean accuracy of maxillary central incisor rotation was 62.61%. The rotation accuracy of IO group[(69.5±3.81)%] is higher than N group[(55.72±4.05)%](P 0.05). The mean accuracy of maxillary premolar rotation was 46.96%. The rotation accuracy of B group[(51.33±1.66)%]is higher than AO group[(45.47±2.07)%]and IO group[(49.02±1.48)%](P<0.05), The rotation accuracy of IO group and AO group were both higher than N group [(42.03±2.40)%](P<0.05). \n \n \nConclusions \nIPR can improve the accuracy of rotation correction for maxillary central incisor, maxillary lateral incisor, maxillary canine and maxillary premolar with removable clear appliance. Attachments can not significantly improve the accuracy of canine rotation, and although it can increase the accuracy of maxillary premolar rotation, the degree of improvement is relatively low. \n \n \nKey words: \nRemovable clear appliance;\xa0Teeth rotation;\xa0Interproximal reduction;\xa0Attachment