Smile esthetics: Perception and comparison of treated and untreated smiles

WOS: 000235046200009PubMed ID: 16443472Introduction: Although orthodontic treatment is based primarily on occlusal relationships, greater attention is now paid to enhancing dentofacial characteristics to produce optimal facial esthetics. The purposes of this study were to compare smile esthetics among extraction and nonextraction patients and a control group, assess certain dentofacial characteristics in those groups, and discuss how these features relate to smile esthetics. Methods: Panels of orthodontists, plastic surgeons, artists, general dentists, dental professionals, and parents used a 5-point scale to rate smiling photographs of 25 extraction, 25 nonextraction, and 25 untreated control subjects. Dentofacial characteristics of the 3 groups were obtained from lateral cephalometric analyses, direct biometric measurements, and frontal photographs. Smile esthetics and differences among the 3 groups were subjected to 1-way analysis of variance (ANOVA), and Pearson correlation coefficients were calculated to determine the relationship of the variables to the esthetic score. Results: The mean esthetic scores for the extraction, nonextraction, and control groups were 3.15, 3.12, and 3.26, respectively. Visible dentition width relative to the smile width ratio and intercanine distance relative to smile width ratio were significantly different among the groups, with extraction patients showing a slightly wider dental arch relative to the soft tissue (P < .05). There was also a significant difference in the U1-SN angle among the groups (P < .05), and this variable showed a strong correlation with the esthetic score as did maxillary gingival display (P < .05). However, our study groups could not be differentiated in smile esthetics

Do long-term changes in relative maxillary arch width affect buccal-corridor ratios in extraction and nonextraction treatment?

PubMed ID: 21392691Introduction: Our aims were to evaluate long-term maxillary arch width changes in orthodontic patients treated with and without premolar extractions and to provide a potential link to the buccal-corridor ratios. Methods: Dental casts of 34 extraction and 32 nonextraction orthodontic patients with Class I malocclusions were digitized and evaluated before treatment (T1), at posttreatment (T2), and at postretention (T3). The mean postretention times for the extraction and the nonextraction groups were 5 years 2 months and 4 years 10 months, respectively. Specific arch width measurements were made on the anatomic y-axis of the casts between the most labial aspects of the anatomic dental arch immediately distal to the incisive papilla, the farthest point posteriorly of the conjunction of the third lateral and medial rugae on the midpalatal raphe and at an individually constant distance from the incisive papilla. Arch width changes were calculated and compared statistically to determine whether the dental arches were narrower after extraction treatment and at postretention. Results: All maxillary arch width measurements remained virtually stable after extraction therapy and at the postretention follow-up. Significant increases were recorded for all maxillary arch width measurements in the nonextraction group after treatment (mean changes, 1.37-2.05 mm). Posterior arch width measurements decreased significantly between T2 and T3 (mean change, 0.5 mm). Mean changes between T1 and T2 were significant between the 2 groups for all measurements (P <0.05). Only the mean change in posterior arch width was significant between the 2 groups in the postretention period (P <0.05). Conclusions: Extraction treatment did not result in narrower maxillary dental arches, whereas nonextraction treatment slightly expanded the dental arch. Copyright © 2011 by the American Association of Orthodontists