Objective: To evaluate the position of the lower incisors in subjects with different facial patterns following use of a fixed spring induced appliance (FSIA) and full fixed multi-banded/bonded orthodontic therapy (FMB treatment). Materials and Methods: A retrospective sample of 115 subjects exhibiting class II malocclusions was used. Subjects were categorized into three growth types according to pre-treatment cephalometric variables (MP-SN and Y-axis), which yielded 28 brachycephalic, 54 mesocephalic, and 31 dolichocephalic subjects. An ANOVA test statistic was used to investigate the differences between the three facial groups. Lateral cephalograms were taken at initial treatment (T0), post-FSIA treatment (T1) & end of active FMB treatment (T2). Results: Dental changes induced by the FSIA & FMB treatment (T2-T0) included: retroclination of the lower incisors (L1-MP: 1.7°±0.9, L1-APo: 3.4°±0.8, L1-NB: 2.2°±0.9), retrusion of the lower incisors (L1-APo: 1.7mm±0.3, L1-NB: 0.2mm±0.06), reduction in the overjet (4mm±0.2) and the overbite (2.8mm±0.3). Facial patterns were not significantly influenced by the FSIA and FMB treatment (MP-SN: 1.8°±0.6; Y-Axis: 0.9°±0.5). Reduction of the skeletal Class II relationship was represented by a significant decrease (p<0.05) of the Wits value (2.3mm±0.2) in all three groups. Lower incisor angular and linear changes at T2 were all proclined and protruded to the initial values at T0. Conclusions: The lower incisors at the end of treatment (T2) remained within normal cephalometric values. The overall change in the position of the lower incisors was proclination and protrusion at T2-T0 and retroclination and retrusion at T2-T1. When T2-T0 was compared, the lower incisors were proclined and protruded to their original position. Facial growth pattern appeared to be unrelated to the amount of dental movement and there was a trend for more pronounced dental retroclination and retrusion of the lower incisors in brachycephalic patients.

No description available.

No description available.

Thesis (M.S.)--University of Michigan, 1981.

Thesis (M.S.)--University of Michigan, 1984.

Thesis (M.S.)--University of Michigan, 1981.

Thesis (M.S.)--University of Michigan, 1984.

INTRODUCTION: Evaluate how esthetic smiling variables influence laypeople’s preference for a step or no step between the incisal edges of the maxillary central and lateral incisors, and how subject demographics may modify such an association. METHODS: Sixteen smiling photographs with differing esthetic variable combinations were duplicated and paired. One of each pair was modified to create a 1mm step between the maxillary central and lateral incisors, while the other picture had no step. Photos were shown to 200 laypeople, and they were asked to choose which smile they prefer for each pairing. RESULTS: 99% of the subjects did not realize any difference between the photos in each pairing. 63% of the subjects surveyed in this study were college educated. For ten out of sixteen esthetic combinations, people preferred no step between central and lateral incisors. People younger than 43 years of age preferred no step for four esthetic categories. In one of the esthetic categories, males preferred a step, while females preferred no step. Caucasians and other racial backgrounds preferred no step for one esthetic combination. For two categories, people who did not attend college preferred a step, and those who did attend college preferred no step. CONCLUSIONS: More people prefer no step between maxillary central and lateral incisors, and patient background and demographics have little-to-no influence on this preference.

No description available.

No description available.