No abstract

No abstract

Objective: To evaluate the influence of attachments and interproximal reduction on canines undergoing rotational movement with Invisalign. Materials and Methods: In this prospective clinical study, 53 canines (33 maxillary and 20 mandibular) were measured from the virtual TREAT models of 31 participants treated with anterior Invisalign. The pretreatment virtual model of the predicted final tooth position was superimposed on the posttreatment virtual model using ToothMeasure, Invisalign's proprietary measurement software. A one-way analysis of variance (ANOVA) (P Ͻ .05) compared three treatment modalities: attachments only (AO), interproximal reduction only (IO), and neither attachments nor interproximal reduction (N). Student's t-tests (P Ͻ .05) compared the mean accuracy of canine rotation between arches. Results: The mean accuracy of canine rotation with Invisalign was 35.8% (SD ϭ 26.3). Statistical analyses indicated that there was no significant difference in accuracy between groups AO, IO, and N (P ϭ .343). There was no statistically significant difference (P ϭ .888) in rotational accuracy for maxillary and mandibular canines for any of the treatment groups. The most commonly prescribed attachment shape was the vertical-ellipsoid (70.5%). Conclusions: Vertical-ellipsoid attachments and interproximal reduction do not significantly improve the accuracy of canine rotation with the Invisalign system.

No abstract

No abstract

No abstract

Objectives: To test the hypotheses that the Damon system will maintain intercanine, interpremolar, and intermolar widths. To test subsequent hypotheses that the Damon system will not produce a significant difference in maxillary and mandibular incisor position/angulation when compared with control groups treated with conventional fixed orthodontic appliances for similar malocclusion. Materials and Methods: Subjects treated with the Damon system (N 5 27) were compared with subjects treated with a conventionally ligated edgewise bracket system (N 5 16). Subjects' pretreatment and posttreatment lateral cephalometric radiographs and dental models were scanned, measured, and compared to see whether significant differences exist between time points and between the two groups. Results: Results did not support the claimed lip bumper effect of the Damon system and showed similar patterns of crowding alleviation, including transverse expansion and incisor advancement, in both groups, regardless of the bracket system used. Conclusions: Maxillary and mandibular intercanine, interpremolar, and intermolar widths increased significantly after treatment with the Damon system. The mandibular incisors were significantly advanced and proclined after treatment with the Damon system, contradicting the lip bumper theory of Damon. Posttreatment incisor inclinations did not differ significantly between the Damon group and the control group. Patients treated with the Damon system completed treatment on average 2 months faster than patients treated with a conventionally ligated standard edgewise bracket system. (Angle Orthod. 2011;81:647-652.)

No abstract