Cephalometric effects of Twin-block and van Beek Headgear-Activator in the correction of Class II malocclusion.

INTRODUCTION: The Twin-block (TB) and the van Beek Headgear-Activator (vBHGA) are indicated for patients with Class II malocclusion with a retrognathic mandible. Although the former is commonly prescribed for horizontally growing patients, the latter is often recommended for those growing vertically. This study aimed to compare the skeletal, dentoalveolar, and soft-tissue short-term effects of TB and vBHGA, taking growth patterns into account. METHODS: Immediate prefunctional (T1) and postfunctional appliance (T2) lateral cephalometric radiographs were retrospectively obtained for vBHGA (n = 46), TB (n = 45), and untreated control (n = 45) groups. The interaction of several variables at T1, T2, and T2 - T1, as well as the resultant treatment effect, were analyzed using the analysis of covariance regression models at the 5% significance level. RESULTS: Except for a greater reduction in Wits measurement (3.0 mm; P <0.0001) in the TB group, no anteroposterior (AP) skeletal difference was observed between the 2 appliances (ANB, 0.530; P = 0.07) (Harvold, 0.13 mm; P = 0.81). Both improved the AP skeletal relationship (ANB and Harvold) compared with the control (P <0.05). Although this mostly occurred because of the forward positioning of the mandible with the TB (SNB, 0.960; P = 0.01), the maxillary restriction was the main mechanism with the vBHGA (SNA, 1.590; P <0.01). Dentoalveolar compensations were more pronounced with the TB (IMPA, 1.92; P = 0.02), leading to greater overbite and overjet correction. Only the inclination of the maxillary incisors showed interaction with the growth pattern, with the TB horizontal growers experiencing more retroclination (U1-NA°. 3.620; P = 0.0067). CONCLUSIONS: Both appliances produced similar modest AP skeletal changes that, together with dentoalveolar compensations, were able to correct the Class II malocclusion regardless of growth pattern.

Influência do Desvio da Linha Média Superior na Atratividade do Sorriso / Influence of Upper Midline Deviation on Smile Attractiveness / Influencia de la desviación de la línea media superior en el atractivo de la sonrisa

Resumo Introdução e objetivo: a análise do sorriso diante de um tratamento odontológico é imprescindível e deve sempre levar em consideração fatores como: idade do paciente, anomalias de tamanho e forma dos dentes, formato do rosto, lábios, cor, presença de diastemas, desvios de linha média dentária, entre outros. Investigar a possível influência do desvio da linha média superior na atratividade do sorriso em adolescentes. Métodos: foram utilizadas seis fotografias frontais de sorrisos posados de voluntários adolescentes tratados ortodonticamente que apresentavam uma oclusão aparentemente normal e a linha média dentária superior coincidente com a linha média facial e com a inferior. Cada fotografia real foi manipulada com auxílio do Adobe Photoshop 7.0, para obter-se fotografias com desvio de linha média superior de 1 a 4mm, totalizando 30 fotografias. Tais imagens foram analisadas por cirugiões-dentistas, alunos de odontologia e adolescentes leigos, os quais as classificaram levando em consideração a estética do sorriso. Para verificar a atratividade do sorriso foi utilizado a análise de variância (ANOVA) para a avaliação inter e intra-grupos, além da correlação de Pearson. Resultados: os grupos de alunos e cirurgiões-dentistas mostraram correlação negativa entre o desvio da linha media e a atratividade do sorriso (p≤0,05). Foi possível observar que não houve diferença estatisticamente significante na avaliação feita por adolescentes leigos independente do grau de desvio de linha média. Conclusão: desvios de linha média superior prejudicam a atratividade de sorriso quando avaliadas por pessoas que têm conhecimento sobre a área odontológica.

Abstract Introduction and objective: the analysis of the smile in the face of dental treatment is essential and must always take into account factors such as: age of the patient, anomalies in the size and shape of the teeth, face shape, lips, color, presence of diastema, dental midline deviations, between others. To investigate the possible influence of the deviation of the upper midline on the attractiveness of the smile in adolescents. Materials and methods: six frontal photographs in posed smile were selected from orthodontically treated adolescent volunteers who had an apparently normal occlusion and an upper dental midline coincident with facial and lower midline. Each real photograph was manipulated with the aid of Adobe Photoshop 7.0, in order to obtain photographs with an upper midline deviation of 1 to 4mm, totaling 30 photographs. Such images were analyzed by graduated dentists, dentistry students and lay adolescents, who classified them considering the aesthetics of the smile. To check the attractiveness of the smile, analysis of variance (ANOVA) was used for inter and intra-group evaluation, in addition to Pearson's correlation. Results: the groups of students and dentists showed a negative correlation between the deviation from the midline and the attractiveness of the smile (p ≤0.05). It was possible to observe that there was no statistically significant difference in the assessment made by lay adolescents, regardless of the degree of deviation from the midline. Conclusion: deviations from the upper midline impair the smile attractiveness when evaluated by people who are knowledgeable about the dental field.

Resumen Introducción y objetivo: el análisis de la sonrisa de cara al tratamiento odontológico es fundamental y siempre debe tener en cuenta factores como: edad del paciente, anomalías en el tamaño y forma de los dientes, forma de la cara, labios, color, presencia de diastemas, desviaciones de la línea media, entre otros. Investigar la posible influencia de la desviación de la línea media superior en el atractivo de la sonrisa en adolescentes. Materiales y métodos: se utilizaron seis fotografías frontales en sonrisa posada tomadas a adolescentes voluntarios tratados con ortodoncia que tenían oclusión aparentemente normal y línea media dentaria superior coincidente con línea media facial e inferior. Cada fotografía real fue manipulada con la ayuda de Adobe Photoshop 7.0, con el fin de obtener fotografías con una desviación de la línea media superior de 1 a 4 mm, totalizando 30 fotografías. Tales imágenes fueron analizadas por odontólogos graduados, estudiantes de odontología y adolescentes legos, quienes las clasificaron teniendo en cuenta la estética de la sonrisa. Para verificar el atractivo de la sonrisa, se utilizó el análisis de varianza (ANOVA) para la evaluación inter e intra-grupo, además de la correlación de Pearson. Resultados: los grupos de estudiantes y dentistas mostraron una correlación negativa entre la desviación de la línea media y el atractivo de la sonrisa (p ≤0.05). Se pudo observar que no hubo diferencia estadísticamente significativa en la evaluación realizada por los adolescentes legos independientemente del grado de desviación de la línea media. Conclusión: las desviaciones de la línea media superior perjudican el atractivo de la sonrisa cuando son evaluadas por personas que tienen conocimientos sobre el campo dental.

Association Between Dental Arch Widths and Interarch Relationships in Children With Operated Unilateral Complete Cleft Lip and Palate.

OBJECTIVE: Palate and lip repair have great influence on the sagittal and transverse growth of the maxilla. The correlation between arch widths and sagittal interarch relationships in operated patients with complete unilateral cleft lip and palate (UCLP) in the mixed dentition is not clear. The aim of this study was to compare the maxillary arch widths of patients with UCLP and different interarch relationships (GOSLON Yardstick index). METHODS: The study sample consisted of 144 pairs of dental casts of patients with complete UCLP from 8 to 10 years of age, from a single center. These dental casts were divided into three groups: group I (patients with GOSLON Yardstick 1 and 2 interarch relationships), group II (GOSLON Yardstick 3), and group III (GOSLON Yardstick 4 and 5). The control group consisted of 40 pairs of dental casts of noncleft Class I patients at the same age range. The maxillary and mandibular arch widths were measured at canine, deciduous molars, and permanent first molar regions. Intergroup comparisons were performed by analysis of variance followed by Tukey tests (P < .05). RESULTS: Maxillary arch widths were significantly smaller in all three groups with repaired UCLP compared to the control group. Group III showed reduced intercanine and second deciduous molar widths compared to group I. No intergroup differences were observed for mandibular arch widths. CONCLUSIONS: Operated UCLP patients with more severe sagittal discrepancies tend to show more severe transverse maxillary arch deficiencies.