Three-dimensional evaluation of tooth movement in Class II malocclusions treated without extraction by orthodontic mini-implant anchorage

Abstract

ObjectiveThe aim of this study was to analyze tooth movement and arch width changes in maxillary dentition following nonextraction treatment with orthodontic mini-implant (OMI) anchorage in Class II division 1 malocclusions.MethodsSeventeen adult patients diagnosed with Angle's Class II division 1 malocclusion were treated by nonextraction with OMIs as anchorage for distalization of whole maxillary dentition. Three-dimensional virtual maxillary models were superimposed with the best-fit method at the pretreatment and post-treatment stages. Linear, angular, and arch width variables were measured using Rapidform 2006 software, and analyzed by the paired t-test.ResultsAll maxillary teeth showed statistically significant movement posteriorly (p < 0.05). There were no significant changes in the vertical position of the maxillary teeth, except that the second molars were extruded (0.86 mm, p < 0.01). The maxillary first and second molars were rotated distal-in (4.5°, p < 0.001; 3.0°, p < 0.05, respectively). The intersecond molar width increased slightly (0.1 mm, p > 0.05) and the intercanine, interfirst premolar, intersecond premolar, and interfirst molar widths increased significantly (2.2 mm, p < 0.01; 2.2 mm, p < 0.05; 1.9 mm, p < 0.01; 2.0 mm, p < 0.01; respectively).ConclusionsNonextraction treatment with OMI anchorage for Class II division 1 malocclusions could retract the whole maxillary dentition to achieve a Class I canine and molar relationship without a change in the vertical position of the teeth; however, the second molars were significantly extruded. Simultaneously, the maxillary arch was shown to be expanded with distal-in rotation of the molars.

Clinical application of an intraoral scanner for serial evaluation of orthodontic tooth movement: A preliminary study

“…Most previous studies on orthodontic tooth movement have compared only the differences between the pretreatment and posttreatment periods. 5 6 7 8 During treatment, however, clinicians frequently have to evaluate tooth movement to decide whether to change the arch wires and/or biomechanics. However, acquiring repetitive cephalograms and CBCT images increases the risk of radiation exposure.…”

“… 2 3 4 Some investigators tried to evaluate orthodontic tooth movement by superimposing digital models obtained from dental casts. 5 6 7 8 However, their evaluations compared only the differences between the pretreatment and posttreatment periods. Consequently, much important information on various tooth movements during treatment, especially during initial leveling and alignment, were overlooked.…”

Three-dimensional analysis of tooth movement in Class II malocclusion treatment using arch wire with continuous tip-back bends and intermaxillary elastics

“…The reference points, lines, and planes used for measurements in the present study are shown in Figure 4. The facial axis (FA) points19 of maxillary teeth have been used as reference points for measurement in previous studies718 because incisal edges or cusp tips could be changed during orthodontic treatment. Therefore, the FA points were used as the reference points for all measurements in our study.…”

“…Various treatment methods have been introduced to correct Class II malocclusion, depending on the severity of the discrepancy. These treatments include orthopedic treatment, premolar or molar extraction, multiloop edgewise arch wire (MEAW) technique,12 intermaxillary elastics, maxillary molar distalization combined with headgear or intraoral appliances, such as superelastic NiTi wires,3 distal jets,4 and molar sliders,5 orthodontic mini-implants (OMI),67 and surgical procedures.…”

Three-dimensional evaluation of the maxillary dentoalveolar changes with three different intraoral distalization systems: Jones Jig, Distal Jet and First Class

“…The sample size calculation was based on an alpha significance level of 5% and a beta of 20%, to detect a mean difference of 2.04 mm, with a standard deviation of 1.41 mm in the sagittal displacement of the maxillary first molar, reported in a previous study. 21 A minimum of 11 patients were required in each group based on the sample size calculation. Thus, to increase the power of the study 17 patients were included in each group.…”