Malocclusion or laterorhinia: Which one impacts aesthetic facial perception the most?

INTRODUCTION: This study aimed to evaluate the perception of facial attractiveness when nose and teeth, together or isolated, present different degrees of disharmony. The secondary objective was to compare the perception of laypersons with that of dentists. MATERIALS AND METHODS: This cross-sectional observational study included 112 individuals (58 laypersons and 54 dentists) that evaluated 6 manipulated images of the face of the same model, scoring their attractiveness using 10 cm Visual Analogue Scales (VAS), with least and most attractive at the left and right anchors, respectively. The images contained manipulations performed only on the nose (laterorhinia) and mouth (misaligned teeth), as follows: (1) standard photograph, with symmetrical nose + aligned teeth; (2) 2 mm nasal deviation + aligned teeth; (3) 4 mm nasal deviation + aligned teeth; (4) symmetrical nose + misaligned teeth; (5) 2 mm nasal deviation + misaligned teeth and (6) 4 mm nasal deviation + misaligned teeth. We used the repeated measures ANOVA test and Tukey's post-test for intra-group comparison of the images. The independent t-test was used for inter-group comparison of each image. RESULTS: In the laypersons' group, the highest grades were given to images with aligned teeth and the lowest to misaligned teeth (smallest mean difference = 2.88 cm). For this group, there was no statistically significant difference (P-values ranged from .988 to 1.000) between scores of the three images in which teeth were aligned (range of 7.70-7.78 cm). In the group of dentists, highest grades were given to images with aligned teeth and the lowest to misaligned teeth. Difference between images 3 and 4 was not statistically significant (P = .204). All other differences between any image of straight teeth and any image with misaligned teeth were significant and the smallest mean difference between the two groups of images was 1.87 (P = .039). However, in the images with aligned teeth, there was also a statistically significant difference with higher scores to the images with symmetrical nose in contrast with those with significant laterorhinia (mean difference = 1.03 cm). CONCLUSION: Teeth disharmonies had a more negative impact on the aesthetic perception of the face than did nose deviations, for both dentists and laypersons.

Space closure using aligners.

INTRODUCTION: Due to the search for more aesthetic and comfortable alternatives to perform orthodontic treatments and to the great technological development, orthodontic aligners have assumed great importance. More and more complex treatments have been carried out with these appliances without, however, having all aspects involved in their use being studied in depth. Its biomechanical planning requires different approaches than those used in fixed orthodontics, as the force systems involved in movements, responses and side effects are distinct, and the professional must be prepared when opting for the technique. OBJECTIVE: The objective of this article is to perform an evaluation of the force systems created on the space closure with aligners, its characteristics, and problems, as well as make some suggestions to overcome the difficulties inherent to its use. CONCLUSION: Space closure with aligners is possible, but depends on the correct selection of the patient, in addition to requiring the proper planning of the applied forces. The use of auxiliary resources and overcorrections to address the deficiencies of the aligner systems should always be considered. Digital planning should be used as a map of the force systems that will be applied, and not just as a marketing tool, keeping in mind that determining the objectives and the way to achieve them is the responsibility of the orthodontist, and that treatment plans must be individualized for each situation, following appropriate biomechanical precepts.

Space closure using aligners

ABSTRACT Introduction: Due to the search for more aesthetic and comfortable alternatives to perform orthodontic treatments and to the great technological development, orthodontic aligners have assumed great importance. More and more complex treatments have been carried out with these appliances without, however, having all aspects involved in their use being studied in depth. Its biomechanical planning requires different approaches than those used in fixed orthodontics, as the force systems involved in movements, responses and side effects are distinct, and the professional must be prepared when opting for the technique. Objective: The objective of this article is to perform an evaluation of the force systems created on the space closure with aligners, its characteristics, and problems, as well as make some suggestions to overcome the difficulties inherent to its use. Conclusion: Space closure with aligners is possible, but depends on the correct selection of the patient, in addition to requiring the proper planning of the applied forces. The use of auxiliary resources and overcorrections to address the deficiencies of the aligner systems should always be considered. Digital planning should be used as a map of the force systems that will be applied, and not just as a marketing tool, keeping in mind that determining the objectives and the way to achieve them is the responsibility of the orthodontist, and that treatment plans must be individualized for each situation, following appropriate biomechanical precepts.

RESUMO Introdução: Devido à busca por alternativas mais estéticas e confortáveis para realizar tratamentos ortodônticos e ao grande desenvolvimento tecnológico, os alinhadores ortodônticos assumiram uma grande importância. Tratamentos cada vez mais complexos vêm sendo realizados com esses dispositivos sem que, no entanto, sejam estudados em profundidade todos os aspectos envolvidos na sua utilização. Seu planejamento biomecânico requer abordagens diferentes da Ortodontia fixa, pois os sistemas de forças envolvidos nas movimentações, respostas e efeitos colaterais são distintos, e o profissional deve estar preparado ao optar por essa técnica. Objetivo: O objetivo deste artigo é fazer uma avaliação dos sistemas de forças envolvidos no fechamento de espaços com alinhadores, suas características e problemas, bem como apresentar algumas sugestões para contornar as dificuldades decorrentes de seu uso. Conclusão: O fechamento de espaços com alinhadores é possível, mas depende da correta seleção do paciente, além de exigir o adequado planejamento das forças aplicadas. O uso de recursos auxiliares e sobrecorreções para suprir as deficiências dos sistemas de alinhadores deve ser sempre considerado. O planejamento digital deve ser usado como um mapa dos sistemas de forças que serão aplicados, e não apenas como ferramenta de marketing, tendo em mente que a determinação dos objetivos e da maneira de atingi-los é de responsabilidade do ortodontista e que os planejamentos devem ser individualizados para cada situação, seguindo preceitos biomecânicos adequados.

Influence of canine vertical position on smile esthetic perceptions by orthodontists and laypersons.

INTRODUCTION: Our objectives were to verify the impact of alterations in the vertical position of the maxillary canines in smile esthetic perceptions and to determine whether exposure of the gingival margins directly affects laypersons' and orthodontists' perceptions. METHODS: A smile photograph of a male subject showing gingival zeniths was selected, and the canine vertical positions were symmetrically modified in increments of 0.5 mm, creating 4 new images varying from 1.0 mm of intrusion to 1.0 mm of extrusion, with and without gingival exposure. The total of 10 images were evaluated by 60 orthodontists and 60 laypersons, who determined the level of attractiveness of each smile on a visual analog scale. RESULTS: For both orthodontists and laypersons, the canine vertical position modifications had a statistically significant influence (P <0.0001), and the gingival exposure had no significant influence on the smile esthetic evaluations. CONCLUSIONS: For both groups of evaluators, the most attractive smiles were the standard smile and the smiles with 0.5 mm of intrusion. The less attractive smiles were those with 1.0 mm of extrusion and 1.0 mm of intrusion. Orthodontists were more critical in their assessments. There were no differences in the esthetic evaluations of smiles with and without gingival margin exposure for both groups of evaluators.

Variations between maxillary central and lateral incisal edges and smile attractiveness.

INTRODUCTION: In this study, we aimed to verify whether different levels of maxillary incisal edges influence the perception of smile attractiveness and whether gingival display affects this perception according to groups of orthodontists, dentists, orthodontic patients, and laypersons. METHODS: Photographs of the smiles of 1 man and 1 woman showing the gingival contours of the incisors and the canines were digitally altered, creating steps from 0 to 2.0 mm in 0.5-mm increments, with and without gingival exposure. The 20 pictures were shown in random order to 240 evaluators divided into 4 groups who were asked to provide attractiveness scores on visual analog scales. RESULTS: Both the steps (P <0.001) and the gingival exposure (P <0.05) had statistically significant influences on the evaluations in all groups. There was also a statistically significant difference (P <0.001) between the evaluations of orthodontists and the other groups, with distinct patterns. CONCLUSIONS: The most accepted vertical relationship of incisor borders was the 1.0-mm step. There were significant differences in the evaluation of orthodontists when compared with the other 3 groups, and no significant difference was detected between these groups. The gingival display altered significantly the esthetic perception of the smiles evaluated. There were significant differences between the evaluations of the smiles of the man and the woman.

Avaliação in vitro do desempenho da alça ortodôntica em T / In vitro evaluation of the performance of orthodontic T-loops

O objetivo deste estudo foi avaliar em testes de tração os efeitos na relação carga/deflexão de alças de retração em T quando alterados na confecção o tipo de liga metálica (aço inoxidável ou titânio-molibdênio -TMA) e a altura (7 e 9 mm). Quarenta alças foram confeccionadas combinando os dois fios e as duas alturas, divididas em 4 grupos (10 alças por grupo), mantendo-se uma dimensão horizontal de 10 mm. Os testes foram realizados em máquina para ensaios de tração com célula de carga, onde as alças de cada grupo sofreram ativações a partir de 1 mm até 3 milímetros, com intervalos de 0,5 mm. Os resultados mostraram que tanto a variação da liga quanto da altura da alça produziram variação significativa na relação carga/deflexão. Foi feita uma comparação entre os níveis de força encontrados em cada uma das situações testadas e os valores recomendados na literatura científica para retração dos dentes anteriores. Foi observado que para 1,0 mm de ativação, apenas as alças de aço com 7 mm de altura atingiram os níveis de força recomendados. Para as ativações de 1,5 e 2,0 mm, tanto as alças de aço de 9 mm quanto as alças de TMA com 7 mm atingiram tais valores. Para as ativações de 2,5 e 3,0 mm, apenas as alças de TMA com 9 mm de altura foram consideradas seguras, uma vez que todas as demais produziram forças demasiadamente altas para o uso clínico...

The aim of this study was to evaluate, in traction test, the effects on the load/deflection rate of the T-loop, when changing the type of alloy used in its confection (stainless steel-SS -or Titanium-Molybdenum alloy - TMA), and the height of the loop (7 and 9 millimeters). Forty loops were bent combining the two alloys and the two heights, divided in four groups of 10 loops each. The horizontal dimension was kept in 10 mm. The tests were made in a traction test machine with a load cell, where the loops from each group were activated from 1 to 3mm in steps of 0.5mm. Results showed that both the variation of the alloy and the variation of the height produce significant changes in the load/deflection rate. A comparison was made between the forces found in each of the situations tested and the numbers suggested in the scientific literature for anterior retraction, and it was observed that, for activations of 1mm, only the SS 7mm high loops reached the levels recommended. For activations of 1.5 and 2.0mm, both the loops made of SS 9mm high and the ones made of TMA 7mm high delivered the necessary force. For activations of 2.5 and 3.0 mm, only the TMA loops 9mm high were considered safe for clinical use, since all the other loops delivered excessive force...