Baby-Risk of malocclusion assessment index An assessment tool for preventive orthodontic treatment needs in a selected population of children in southeast of Iran

Context: Preventive orthodontic treatments are performed in the primary or mixed dentition period and provide a proper development of occlusion to avoid dentofacial anomalies. Aims: This study aims to evaluate the Baby-Risk of Malocclusion Assessment Index (ROMA) index regarding ease of use, reproducibility, and the epidemiological assessment of major orthodontic problems in children aged 4–6-year-old in Kerman (Iran) kindergartens. Setting and Design: This cross-sectional study was conducted on 1000 children aged 4–6 in Kerman (Iran) kindergartens, selected by cluster sampling, and data were collected using the Baby-ROMA index. Methods: After recording a demographic data collection form, the clinical examination of the teeth was carried out by a dental student. The data were analyzed with SPSS 18 using t-test, analysis of variance, Chi-squared test, and Mann–Whitney test at a significance level of P < 0.05. Results: In this study, the most common cause of malocclusion was dental caries (7.5%), followed by crossbite (6.1%). Furthermore, 31.6% of the subjects had one type of malocclusion, and 20.5% needed monitoring the occlusion before the growth spurt, while 11.1% needed immediate orthodontic treatment (mostly 6-year-old children). Moreover, 15.3% of the subjects had systemic problems; 3.4% had craniofacial, 22% had dental, and 2% had functional problems. The prevalence of class I canine relationship in the right canines was 82.32%, with 82.5% on the left side. The prevalence of open bite was higher in females with thumb-sucking habit. Conclusion: The Baby-ROMA index presented good reliability and ease of use for evaluating early orthodontic treatment needs in primary and mixed dentition periods.

Comparison of two asymmetric headgear force systems: A finite element analysis

Abstract Objective: The aim of this study was to evaluate the effect of displacement patterns of the molar teeth in response to different asymmetric headgear loading using 3D finite element method. Methods: A series of twenty-five facebow with different left vs. right outer bow length and different expansion of left vs. right were designed. The non-favored side (right side) was shortened at intervals of 10 mm, and favored side (left side) was expanded 10 degree greater than right side and 5 degree expansion were successively added. At the first phase, each side received 200-g load, implying the neck strap to displace toward shorter arm. At the second phase, a total of 400-g load was applied to the ends of the outer bow. Because of the neck strap displacement, the shorter arm received greater load than the left side, the magnitude of the applied force to each side depended on difference of left vs. right outer bow length and expansion. Results: All systems were effective in promoting asymmetric distal movement of the molars. However, the asymmetrical facebow with the 40 mm shortening and 25 degree expansion outer bow when unequal force applied could be used in asymmetric mechanics. Medial and occlusal displacing forces were observed in all systems. Conclusions: Both equal and unequal force application is effective for molar distalization. Expansion of the outer bow in the affected side and shortening of the outer bow in the normal side were effective to produced differential distal molar movement.

Resumo Objetivo: o objetivo desse estudo foi usar o método de elementos finitos 3D para avaliar o efeito no padrão de deslocamento dos molares em resposta ao uso de aparelhos extrabucais com diferentes forças assimétricas. Métodos: foram confeccionados 25 aparelhos extrabucais (AEB) com diferenças, entre os lados direito e esquerdo, quanto ao comprimento e ao grau de abertura do braço externo. O lado não favorecido (lado direito) foi encurtado em intervalos de 10 mm e o lado favorecido (lado esquerdo) foi aberto 10 graus a mais do que o lado direito, sendo adicionados 5 graus de abertura sucessivamente. Na primeira fase, cada lado recebeu carga de 200 g, causando o deslocamento da tala cervical em direção ao braço mais curto. Na segunda fase, foi aplicada carga total de 400 g às extremidades dos braços externos dos AEB. Devido ao deslocamento da tala cervical, o braço mais curto recebeu uma força maior do que o lado oposto; a magnitude da força aplicada em cada lado dependeu da diferença no comprimento e na abertura dos braços externos do AEB. Resultados: todos os sistemas foram efetivos em promover movimentação distal assimétrica dos molares. Porém, o AEB assimétrico com 40 mm de encurtamento e 25 graus de abertura do braço externo poderia ser usado na mecânica assimétrica, com aplicação diferenciada de força. Foram observadas forças mediais e oclusais de deslocamento em todos os sistemas. Conclusões: tanto a aplicação de forças simétricas quanto assimétricas são efetivas para a distalização dos molares. A expansão do braço externo do AEB no lado afetado e o encurtamento no lado normal foram efetivos na produção de movimento distal assimétrico dos molares.