Perception of adults' smile esthetics among orthodontists, clinicians and laypeople

OBJECTIVE: Smile esthetics has become a major concern among patients and orthodontists. Therefore, the aim of this study was: (1) To highlight differences in perception of smile esthetics by clinicians, orthodontists and laypeople; (2) To assess factors such as lip thickness, smile height, color gradation, tooth size and crowding, and which are associated with smile unpleasantness. METHODS: To this end, edited photographs emphasizing the lower third of the face of 41 subjects were assessed by three groups (orthodontists, laypeople and clinicians) who graded the smiles from 1 to 9, highlighting the markers that evince smile unpleasantness. Kruskall-Wallis test supplemented by Bonferroni test was used to assess differences among groups. Additionally, the prevailing factors in smile unpleasantness were also described. RESULTS: There was no significant difference (P = 0.67) among groups rates. However, the groups highlighted different characteristics associated with smile unpleasantness. Orthodontists emphasized little gingival display, whereas laypeople emphasized disproportionate teeth and clinicians emphasized yellow teeth. CONCLUSION: Orthodontists, laypeople and clinicians similarly assess smile esthetics; however, noticing different characteristics. Thus, the orthodontist must be careful not to impose his own perception of smile esthetics. .

OBJETIVOS: a estética do sorriso tornou-se motivo de preocupação entre pacientes e ortodontistas. Diante disso, esse estudo objetivou (1) apontar as diferenças de percepção estética do sorriso entre grupos diferentes de avaliadores (clínicos, ortodontistas e leigos) e (2) avaliar entre fatores, como espessura de lábio, altura do sorriso, gradação de cor, tamanho dentário e apinhamento, quais estão implicados na desagradabilidade do sorriso. MÉTODOS: para tal, foram avaliados 41 indivíduos, com fotografias editadas, evidenciando o terço inferior da face. Essas fotografias foram avaliadas por três grupos (ortodontistas, leigos e clínicos), que graduaram os sorrisos com notas de 1 a 9 e apontaram marcadores que justificariam a desarmonia do sorriso. O teste de Kruskall-Wallis, complementado pelo teste de Bonferroni, foi empregado para verificação das diferenças entre os grupos de avaliadores. Além disso, os fatores mais prevalentes na desagradabilidade do sorriso foram descritos. RESULTADOS: não houve diferença significativa (p = 0,67) entre os grupos de avaliadores nas notas para avaliação do sorriso. Porém, os grupos apontaram características distintas, contribuindo para a desarmonia do sorriso. Para ortodontistas, a característica que mais contribuiu para a desarmonia do sorriso foi a pouca exposição gengival, enquanto, para os leigos, foram os dentes de tamanhos desproporcionais entre si, e, por último, dentes amarelados foram a característica mais observada pelos clínicos. CONCLUSÃO: concluiu-se que ortodontistas, leigos e clínicos, apesar de avaliarem similarmente a estética dos sorrisos, percebem características morfológicas diferentes. O ortodontista, portanto, deve ter cuidado sobre imposições de sua própria concepção de beleza do sorriso. .

An in vitro comparison of nickel and chromium release from brackets

This study aimed at comparing amounts of nickel (Ni) and chromium (Cr) released from brackets from different manufacturers in simulated oral environments. 280 brackets were equally divided into 7 groups according to manufacturer. 6 groups of brackets were stainless steel, and 1 group of brackets was made of a cobalt-chromium alloy with low Ni content (0.5 percent). International standard ISO 10271/2001 was applied to provide test methods. Each bracket was immersed in 0.5 ml of synthetic saliva (SS) or artificial plaque fluid (PF) over a period of 28 days at 37ºC. Solutions were replaced every 7 days, and were analyzed by spectrometry. The Kruskal-Wallis test was applied. Amounts of Ni release in SS (µg L-1 per week) varied between groups from "bellow detection limits" to 694, and from 49 to 5,948.5 in PF. The group of brackets made of cobalt-chromium alloy, with the least nickel content, did not release the least amounts of Ni. Amounts of Cr detected in SS and in PF (µg L-1 per week) were from 1 to 10.4 and from 50.5 to 8,225, respectively. It was therefore concluded that brackets from different manufacturers present different corrosion behavior. Further studies are necessary to determine clinical implications of the findings.