A survey of correlated ratio in maxillary anterior teeth smiling / 天津医药

Objective To survey aesthetics cognition for smiling beauty in young people smile. Methods Smile model was established. The middle incisor width/length ratio, lateral incisor and middle incisor width ratio, difference of lateral incisor and the middle incisor gingival level, gingiva exposure, buccal corridor width and smile line radian were used as variable values to change respectively. A total of 200 young people were selected to evaluate results. The differences in index of ideal value and acceptable range between different dender groups were calculated. Results The ideal value of middle incisor width/length ratio was 0.75, and acceptable range was 0.65-0.85. The ideal value of lateral incisor and middle incisor width ratio was 0.618, and acceptable range was 0.518-0.718. The ideal value of lateral incisor and the middle incisor gingival level difference was-0.5 mm, and the acceptable range was-1-0 mm. The ideal value of gingiva exposure was 0 mm, and the acceptable range was 0-2 mm. The ideal value of buccal corridor was 0.09, and the acceptable range was 0.05-0.21. Coordinate smile was ideal smile line (value=1), and the acceptable range was 0.5-1. There were no statistically significant differences in smile esthetics of six ideal value indicators and acceptable ranges between different gender groups. Conclusion The ideal values and acceptable ranges of six indexes of quantitative criteria can be used for clinical treatment.

Perception of Smile Attractiveness by Laypeople–influence of Profession and Treatment Experience.

Aims: To assess the influence of profession, treatment experience, age and gender on the perception of smile aesthetics with different buccal corridors and smile arcs, and to identify the threshold where buccal corridor space becomes aesthetically displeasing. Study Design: A questionnaire-based descriptive study on the assessment of attractiveness ratings by laypeople. Place and Duration of Study: Amman/Jordan, University of Jordan Hospital; Faculty of Dentistry, Division of Orthodontics, from 2010-2011. Methodology: A coloured photograph of a female smile was digitally modified to produce six smile images with buccal corridor spaces (BCSs) ranging from 0% to 25% and three smile images with altered smile arcs (consonant, flat and reverse). These images were shown to 104 laypeople who were asked to rate the attractiveness of each smile on a scale of one to ten. Analysis of variance was used to study the effect of age, gender, profession and treatment experience on smile attractiveness rating. A one-way ANOVA post hoc Duncan test was used to establish the threshold where BCS was considered unattractive. Results: The most attractive smile was the broadest and consonant smile (7.42 +/- 1.87). The image with a reverse smile arc was rated as the least attractive (2.65 +/- 1.85). Duncan’s test revealed that the threshold at which BCS was considered significantly unattractive was when it reached 25%. Analysis of variance showed that young adults perceived the broadest smile as significantly more attractive than older adults (P = .03). Profession had a significant influence on smile attractiveness ratings while gender and treatment experience did not. Conclusion: Flattening the smile arc was found to have more of an unattractive bearing than small variations in BCS. Thus, it is advisable to take into consideration the smile arc during any treatment that involves the anterior maxillary area, especially prosthodontic and restorative treatments, orthognathic surgery and orthodontics.

Role of buccal corridor in smile esthetics and its correlation with underlying skeletal and dental structures.

Purpose: This study was designed to evaluate the buccal corridor in smile esthetics and to correlate it with underlying hard tissues. Materials and Methods: Posed smiling frontal photographs, digital posterior-anterior (PA) cephalograms, and study models of 25 males and 25 females in age range of 18-25 years were taken. Photographs were evaluated for smile esthetics by eight orthodontists, eight plastic surgeons, eight beauticians and eight lay people to group them into three groups with least attractive, average and attractive smile and buccal corridor width was measured. Digital PA cephalograms were transferred on Nemo-tech software for frontal facial analysis. Intercanine and intermolar widths were measured on upper study model with the help of a digital calliper. Results: The buccal corridor width was least in attractive smile group and maximum in least attractive smile group. The buccal corridor width had a negligible correlation with hard tissues and a mild to moderate inverse correlation with intercanine and intermolar widths within the groups. Conclusion: As the amount of buccal corridor display was increased, smiling images were scored less attractive by the evaluators. The buccal corridor is not influenced by underlying skeletal hard tissues but have mild to moderate inverse correlation with the intercanine and intermolar width.

Dimensões do corredor bucal em diferentes faixas etárias e sua proporção com a distância inter pré-molar e inter comissura / Dimensions of buccal corridor in different age groups and their proportion with the interpremolar and intercomissure width

O corredor bucal é definido como o espaço que existe bilateralmente entre a superfície vestibular dos dentes superiores posteriores visíveis e a comissura labial durante o sorriso. Este espaço escuro também é conhecido como espaço negativo. O objetivo da presente pesquisa foi analisar o corredor bucal durante o sorriso de 150 indivíduos de 10 a 19 anos de idade, verificando se há mudança no tamanho desse espaço em diferentes idades, se há diferença entre os gêneros e se existe uma relação de proporção entre a distância inter pré-molares, a largura inter comissura e o corredor bucal. Foram realizadas fotografias digitais padronizadas em norma frontal do sorriso amplo posado que foram transferidas para um computador e os contornos das imagens dos corredores bucais e sua medida linear foram delimitados e calculados pelo programa Image Tool 3.0. Uma linha entre as comissuras labiais direita e esquerda foi definida medindo a largura inter comissura. A área inter labial do sorriso e do corredor bucal foi delimitada e calculada. As distâncias entre as cúspides vestibulares dos primeiros pré-molares superiores foram medidas em modelos de gesso comum e as mesmas foram transferidas para um computador para posteriores comparações. A análise dos dados foi realizada obtendo estimativas por intervalo de confiança, análise de variância com dois critérios de classificação, comparação múltipla de médias e coeficiente de correlação de Pearson. O corredor bucal aumentou com a idade. Os indivíduos do gênero masculino apresentam corredor bucal maior que os do gênero feminino, porém em relação ao percentual da largura inter comissura não há diferença entre os gêneros.

The buccal corridor is defined as the space that exists bilaterally between the vestibular surface of the subsequent superior teeth visible and the labial comissure during the smile. This dark space is also known as negative space. The objective of the present research is to analyze the buccal corridor during the smile of 150 individuals from 10 to 19 years of age, verifying if there is change in the size of that space in different ages and if exists a relationship of proportion among the inter premolar distance, the inter comissure width and the buccal corridor. Digital standardized pictures were accomplished in frontal norm of the posed wide smile that were transferred for a computer and the outlines of the images of the buccal corridors and linear measure were delimited and calculated by the program Image Tool 3.0. A line between the right and left comissures was defined measuring the inter comissure width. The inter labial area of the smile and buccal corridors were delimited and calculated. The distances among the vestibular cusps of the first superior premolars were measured in casts of common plaster and were transferred for a computer for subsequent comparisons. The analysis of the data was accomplished obtaining confidence intervals, analysis of variance with two classification criteria, multiple mean test and Pearson correlation coefficient to complete data. Buccal corridor increases with age. Males have bigger buccal corridor than females, but there is no difference between gender when calculated as percentage related with the inter comissure width.