Effects of early treatment of maxillary incisor crowding by using two bands and four brackets (2×4) mechanotherapy

Abstract

The purpose of the present study was to investigate effects of early treatment of maxillary incisor crowding on anteroposterior skeletal and dental changes. Treatment group comprised 17 patients with maxillary incisor crowding treated with the two bands and four brackets ‫)4ן2(‬ mechanotherapy, and with an initial mean age of 8 years and 10 months. Control group consisted of 17 patients with the same type of malocclusion as the treatment group and with an initial mean age of 8 years and 7 months. Lateral cephalograms in the treatment group were obtained at three time periods: T1, at the start of the ‫4ן2‬ mechanotherapy; T2, at the end of the ‫4ן2‬ mechanotherapy; T3, at the end of posttreatment observation. In the control group, lateral cephalograms were obtained at two time periods: T1, at the start of observation; T3, at the end of observation. Ten linear and 10 angular measurements were made for each cephalogram and the cephalometric data obtained were analysed statistically.The significantly large retroclination of the mandibular incisors was found at T1 in both groups compared with Japanese norms, resulting in the obtuseness of the interincisal angle. The resolution of maxillary incisor crowding during T1-T2 produced the retrusive movement of maxillary central incisor tips and the retroclination of mandibular incisors. There were no statistically significant differences for the T1-T3 changes in any linear and angular measurements between both groups. The mandibular incisors were, however, inclined labially during T1-T3 in the treatment group, which were, on the contrary, inclined lingually in the control group. These results suggested that the resolution of maxillary incisor crowding mostly produce the anteroposterior dental effects, and that its effect on the correction of the retroclination of mandibular incisors which was observed at the start of the ‫4ן2‬ mechanotherapy was not so significant.incisor crowding 1-3) .Sanin and Savara 4) , in a longitudinal study of factors affecting the alignment of mandibular incisors, found that a lingual inclination of incisors and a mesial inclination of first molars in the mixed dentition were related to incisor crowding in the permanent dentition. In the investigation of the craniofacial morphology of adults with mandibular anterior crowding compared with those with ideal

Effect of bonding brackets by sulphated polyacrylic vs. Conventional acid etching on deciduous and permanent enamel

“…Most of enamel surfaces treated INTRODUCTION Early orthodontic treatment for various types of malocclusion is recommended to enhance dental and skeletal development before completion of the permanent dentition [1] . A two-by-four sectional edgewise appliance has been used in the mixed dentition for early orthodontic treatment of dental anterior crossbites, maxillary incisor crowding, and maxillary impacted (unerupted) incisors [2][3][4] . To facilitate treatment of these malocclusions, orthodontic brackets might be bonded not only to premolars but also to deciduous canines and molars as well as the four permanent incisors and the two permanent maxillary first molars.…”