Overjet y overbite, un desafío terapéutico / Overjet and overbite, a therapeutic challenge

El estudio de diversas situaciones clínicas revela síntomas y signos que deben ser estudiados desde el punto de vista diagnóstico; el análisis dentario debe considerarse solamente como un aspecto morfológico. Lo importante es que la forma pone de manifiesto la acción de grupos musculares que determinan dicha posición y deben ser reeducados para lograr el equilibrio morfofuncional (AU)

Correlação da curva de spee com overbite, overjet e padrão facial / Spee curve correlation with overbite, overjet and facial pattern

Objetivou-se com o presente estudo verificar a relação entre a profundidade da curva de Spee superior e inferior com o overjet, overbite e o padrão facial. Quarenta e três modelos e radiografias cefalométricas laterais iniciais foram selecionados de pacientes do arquivo do Curso de Especialização de Ortodontia da Faculdade de Odontologia da UERJ, pós-surto de crescimento, com dentição permanente completa e apresentando overjet de 1 a 3 mm. Os modelos foram digitalizados e a profundidade máxima da curva de Spee superior e inferior, o overjet e o overbite foram calculados, utilizando-se o programa 3Shape Ortho Analyser. O padrão facial foi determinado a partir do ângulo SN.GoGn. As associações da curva de Spee superior e inferior com overbite, overjet e padrão facial foram avaliadas através do teste de correlação de Pearson. Encontrou-se associação da profundidade da curva de Spee inferior com o overjet e com a curva de Spee superior. Não houve significância estatística na correlação da curva de Spee inferior com o overbite e padrão facial, nem da curva de Spee superior com o overbite, com o overjet ou com o ângulo do plano mandibular, sugerindo que a curva de Spee inferior acentuada está mais frequentemente associada ao overjet aumentado.(AU)

The aim of this study was to verify the relationship between the depth of the lower and upper curves of Spee with overjet, overbite and facial pattern. Forty-three initial casts and lateral cephalometric radiographs were selected from the archives of the Graduate Program in Orthodontics of Rio de Janeiro State University. All patients were postpubertal, with permanent dentition and presenting an overjet varying from 1 to 3 mm. The cast models were scanned and the maximum depth of the upper and lower curve of Spee, the overjet and the overbite were calculated using the 3Shape Ortho Analyzer software. The facial pattern was determined from the SN.GoGn angle. The associations of the upper and lower curve of Spee with overbite, overjet and facial pattern were assessed using the Pearson correlation test. An association was found between the depth of the lower curve of Spee with the overjet and with the upper curve of Spee. There was no correlation of the lower curve of Spee with the overbite and facial pattern, neither between the upper curve of Spee with the overbite, overjet or the mandibular plane angle, suggesting that a marked lower curve of Spee is more frequently associated with increased overjet. (AU)

Application of RW-splint in clinical diagnosis of classⅡ1 malocclusion patients / 口腔疾病防治

Objective @# To investigate whether the RW-splint could be used to guide or determine the CR position of the lower jaw so as to provide help for the later diagnostic design.@*Methods@#20 class ⅡⅠ malocclusion patients were recruited in orthodontic department of Foshan Stomatological Hospital. They were treated by RW-splint for half a year before orthodontic treatment. The overjet of anterior teeth were recorded before and after treatment. @*Results @#The overjet of anterior teeth was (6.792 ± 0.795) mm before treatment and (7.720 ± 0.930) mm after half a year's treatment. The overjet of anterior teeth had significant difference (t=6.319, P <0.01). The overjet change of anterior teeth between before treatment and half year after treatment was (0.928 ± 0.657) mm. @* Conclusion @#The RW-splint wearing before treatment can be used to guide or determine the mandible in the CR position.

Respiración oral y traumatismo dentoalveolar en niños de 6 a 14 años / Oral breathing and dentoalveolar trauma in children aged 6 to 14 years

Introducción: el trauma dentoalveolar corresponde a una lesión traumática de alta prevalencia, elevado costo de tratamiento y efectos negativos a nivel funcional, estético y psicológico. Existen factores predisponentes de traumatismo dentoalveolar que coinciden con ciertas características de niños respiradores orales, sin embargo, el rol de la respiración oral como factor predisponente no está claramente determinado. Objetivo: determinar la asociación entre respiración oral y trauma dentoalveolar controlando por otras covariables en niños de 6 a 14 años. Métodos: se aplicó un estudio de casos y controles 1:2. La muestra quedó constituida por 57 casos y 113 controles asumiendo un nivel de confianza del 95 por ciento, una potencia del 80 por ciento y un 10 por ciento de pérdidas. Los casos correspondieron a niños de 6 a 14 años de edad ingresados por TDA a la Unidad de Odontopediatría del Hospital Dr. Sótero del Rí", centro de referencia que atiende a una población de 1 521 144 habitantes de la capital. Los controles correspondieron a niños voluntarios sin TDA del mismo centro asistencial y grupo etario. Los datos fueron recolectados a partir de una entrevista, además de la medición clínica y observación directa para determinar el modo respiratorio. Para diferencias entre grupos se aplicó prueba de Fisher y Mann Whitney. La asociación entre respiración oral y trauma dentoalveolar se evaluó a partir de un modelo logístico considerando sexo, resalte y edad. Resultados: la prevalencia de niños respiradores orales fue mayor en los casos con un 47,4 por ciento (p < 0,05), sin embargo, no se pudo establecer una asociación significativa entre respiración oral y trauma dentoalveolar (OR:1,875; IC 95 por ciento: 0,866 - 4,058; p > 0,05) como para ninguna de las covariables del modelo. Conclusiones: respirar a través de la cavidad oral no constituiría un aumento del riesgo de sufrir un trauma dentoalveolar durante un golpe o caída en los niños estudiados(AU)

Introduction: dentoalveolar trauma is a traumatic-high prevalent injury with high costs associated with treatment and adverse effects at functional, aesthetic, and psychological levels. There are some predisposing clinical features of dentoalveolar trauma that are also present in mouth-breathing children, however the role of mouth breathing as a predisposing factor is not clearly determined. Objective: this paper aims to determine the association between mouth breathing and dentoalveolar trauma in children aged 6 to 14 years, controlling other covariates. Methods: a case-control study 1:2 was conducted. The sample was composed of 57 cases and 113 controls, assuming 95 percent of confidence level, 80 percent of power, and 10 percent losses. The cases were children aged 6 to 14 years admitted at the Pediatric Dentistry Unit in Dr. Sotero del Río Hospital because of dental trauma. This hospital assists a population of 1.521.144 inhabitants from the capital city. Controls were conducted on volunteer children of the same age group without dental trauma who are treated at the same hospital. Data were collected from interviews, clinical measurement, and direct observation to determine respiratory mode. The Fisher and Mann Whitney test was applied to find differences between the groups. The association between mouth breathing and dentoalveolar trauma was assessed through a logistical model controlling gender, overjet, and age. Results: the prevalence of mouth-breathing children was higher, which represents 47, 4 percent (p < 0. 05). However, no significant association could be made between mouth breathing and dentoalveolar trauma (OR: 1.875; IC95 percent:0.866-4.058; p > 0. 05) and neither for any of the covariates in this model. Conclusions: breathing through the oral cavity does not constitute an increased risk of dentoalveolar trauma over a bump or fall in children aged 6 to 14 years(AU)

Inclinación de incisivos: cálculo de la cantidad de desplazamiento bucolingual y sus efectos en la longitud del arco dental / Incisor inclination: estimate of the quantity of bucolingual displacement and their effects on the dental arc lenght

Se presentan métodos para calcular con mayor precisión la cantidad de desplazamiento incisal en los movimientos de inclinación bucolingual, basados en las fórmulas longitud de arco y longitud de cuerda de una circunferencia y la ley del senocon centro de rotación dinámico. Cuando se usan arcos preformados de alambre durante las fases de alineación ortodóncica, la inclinación producida sobre los dientes anteriores afecta la forma y la longitud del arco total. Actualmente, esto es un aspectopoco evaluado. Se ofrecen guías para calcular estas variaciones con el propósito de lograr análisis de espacio más exactos. Representaciones y análisis de casos refuerzan esta propuesta.

Methods are presented to calculate more precisely the quantity of incisor displacement during buccolingual inclination movements. It is based on the arc length and chord length of a circle and law of sines with dynamic rotation center formulas. When preformed archwires are used during the orthodontic alignment phases, the inclination taking place on the anterior teeth affects the form and total arch length. At present this aspect has not been evaluated in depth. Guidelines are offered to calculate these variations with the purpose of achieving a more exact space analysis. Representations and case analysis reinforce this proposal.

Avaliação da correlação da recidiva da sobremordida e da sobressaliência com a recidiva do apinhamento anterior em casos tratados sem extrações / Evaluation of the correlation of the relapse of overbite and overjet with the relapse of anterior crowding in cases treated nonextraction

O presente estudo retrospectivo objetivou correlacionar a recidiva da sobremordida e da sobressaliência com a recidiva do apinhamento dos incisivos ântero-superiores e ântero-inferiores. A amostra consistiu de 34 pacientes (17 de cada gênero),apresentando más oclusões iniciais de Classe I e II,tratados sem extração e mecânica Edgewise.O tempo médio de duração do tratamento foi de 2,19 anos e os tempos de contenção e pós-contenção foram de 1,46 e 5,31 anos respectivamente. Todos os pacientes apresentavam, pelo menos, 3 mm de sobremordida e 4 mm de sobressaliência e apinhamento superior e inferior, de suave a severo. Foram medidos nos modelos de estudo das fases pré (T1), pós-tratamento (T2) e pós-contenção (T3) a sobremordida, a sobressaliência e o índice de irregularidade de Little superior e inferior. Após a obtenção dos dados, passou-se à análise estatística. A comparação intergrupos foi realizada por meio do teste t independente. Os testes ANOVA e Tukey foram apl icados para verificar se houve recidiva da sobremordida, da sobressaliência e dos apinhamentos ântero-superior e ântero-inferior. Para verificação da presença de correlação entre a recidiva da sobremordida, da sobressaliência e do apinhamento anterior, utilizou-se o teste de correlação de Pearson. Os resultados evidenciaram recidiva estat ist icamente signi ficante para o apinhamento ântero-super ior e ântero- infer ior . Houve correlação entre a recidiva da sobremordida e da sobressaliência, no entanto, não houve relação entre essas duas recidivas e o apinhamento anterior.

The present study aimed to correlate, by means of a retrospective analysis, the postretention stability of the overbite and overjet with the relapse of the crowding of maxillary and mandibular anterior teeth. The sample comprised 34 subjects (17 of each gender), at a mean initial age of 12.89 years, presenting Class I and II malocclusions, treated nonextraction and Edgewise mechanics.All patients presented at least 3mm of overbite and 4mm of overjet and maxillary and mandibular crowding from slight to severe. It was measured, in the dental casts from the stages pretreatment (T1), posttreatment (T2) and postretention (T3), the overbite, overjet and the maxillary and mandibular Little irregularity index. After data were obtained, the statistical analysis was performed. The intergroup comparison was performed by independent t tests. The ANOVA and Tukey tests were applied to verify the relapse of the overbite, overjet and maxillary and mandibular anterior crowding. To verify the presence of correlation among the relapse of the overbite, overjet and the anterior crowding, the Pearsons correlation test was used. Results did not show statistically significant difference between Angles Class I and Class II patients. There was correlation of the relapse of overbite with the relapse of overjet, however, there was no relationship among the relapse of overbite and overjet with the relapse of anterior crowding.

The relationship between overjet size and dentoalveolar compensation.

Background : The purpose of this study was to investigate the effect of overjet size and the dento-alveolar compensation in subjects with normal class I molar relationship. Materials and Methods: Lateral cephalometric head records of 59 Egyptian children (34 boys and 25 girls) aged 7.5 to 10.5 years with mean age of 8.69±0.73. All had normal class I type of occlusion. The sample was classified into four quartiles according to the overjet size and the cephalometric analysis was based on seven linear and eight angular measurements using a dental tracer programme. Results: showed that, in spite of presence of high significant over jet size differences between the groups; there was no significant differences in all the studied parameters were found. Applying the least significant differences (LSD) test and coefficient correlations between the studied parameters clarifying that there was a significant differences in angular measurements (SN-AB, SN-Occl, I-I, I-ML, I-NB). Conclusion: during transitional dentition there was a sufficient dento-alveolar adaptation to growth changes in the saggittal jaw relation ship to attain normal class I type of occlusion. This compensation is pronounced in angular parameters and clustered in the lower arches particularly in incisal area.

Relationship between abnormal horizontal or vertical dental overlap and temporomandibular disorders / Relação de trespasse vertical e horizontal com desordens temporomandibulares

Purpose: This study investigated if abnormal vertical (overbite) and/or horizontal (overjet) dental overlap are more prevalent in adult subjects with clinical signs of temporomandibular disorders (TMD). Methods: Case-control design. The sample comprised 103 subjects, males and females from 19 to 54 year-old, which were divided into two groups: Group 1 (control) without TMD (n=52) and Group 2 (cases) with TMD (n=51). Inclusion criteria for Group 2 were based on axis I of the RDC/TMD protocol. Two calibrated examiners (Cohen kappa = 0.85) performed the clinical examination to collect data on occlusion and TMD. Data were analyzed by Chi-square tests. Results: Overbite mean values were 3.4 mm (control group) and 2.5 mm (cases group). Abnormal overbite was found in 26 subjects (50%) of the control group and 16 (31%) in the cases group (P=0.054). Overjet mean values were 2.4 mm and 2.0 mm for the control and cases groups, respectively. Abnormal overjet was found in 44 (85%) subjects of the control group and 44 (86%) of the cases group (P=0.811). No significant overall association was found between the tested occlusal variables and TMD (P=0.585). Conclusion: Overbite and overjet were not associated with TMD in this sample.

Objetivo: Este estudo investigou se anormalidades de trespasse vertical (overbite) e/ou horizontal (overjet) são mais prevalentes em sujeitos adultos com manifestações clínicas de desordens temporomandibulares (DTM). Metodologia: Desenho de caso-controle. A amostra consistiu de 103 sujeitos, com idades de 19 a 54 anos, que foram divididos em dois grupos: Grupo 1 (controle) sem DTM (n=52) e Grupo 2 (casos) com DTM (n=51). Os critérios de inclusão para o Grupo 2 basearam-se no eixo I do protocolo RDC/TMD. Dois examinadores calibrados (Cohen kappa = 0.85) realizaram o exame clínico para coleta dos dados de oclusão e de DTM. Data were analyzed by Chi-square tests.Resultados: Os valores médios de overbite foram 3,4 mm (controle) e 2,5 mm (casos). Overbite anormal foi mensurado em 26 sujeitos (50%) do grupo controle e 16 (31%) no grupo casos (P=0,054). Os valores médios de overjet foram de 2,4 mm e 2,0 mm para os grupos controle e casos, respectivamente. Observou-se overjet anormal em 44 (85%) sujeitos do grupo controle e 44 (86%) dos casos (P=0,811). Nenhuma associação significativa foi observada entre as variáveis oclusais testadas e DTM (P=0,585).Conclusão: Overbite e overjet não foram associadas a DTM nesta amostra.

A study on the cephalometric parameters related with anterior overbite / 实用口腔医学杂志

Objective: To investigate the cephalometric parameters related with anterior overbite. Methods: 144 patients with malocclusion in permanent dentition (74 skeletal Class I and 70 skeletal Class II) were recruited into the study. Cephalometric analysis was performed from pre-orthodontic lateral headfilm in natural head position. Both linear correlation analysis and stepwise regression analysis were respectively performed in the two groups. Results: In the stepwise regression equation of Class I group, the larger the overjet, posterior facial height and upper incisor height, or the smaller the lower facial height and lower molar height, the deeper the anterior overbite was. In the 70 Class II, the larger the overjet, interincisal angle and inclination of lower incisors, or the smaller the mandibular angle and upper molar height, the deeper the anterior overbite was. The equations could explain 75.8% and 62.3% overbite variations, respectively. Of all the parameters, overjet took the most important part in maintaining a normal and stable anterior overbite. Conclusion: Those cephalometric parameters correlated with anterior overbite can be both dental and skeletal. They may compensate each other to maintain stable anterior overbite. Of them, anterior overjet may be the main factor.