Reliability of overbite depth indicator (ODI) and anteroposterior dysplasia indicator (APDI) in the assessment of different vertical and sagittal dental malocclusions: a receiver operating characteristic (ROC) analysis.

INTRODUCTION:: Differential diagnosis of skeletal and dental relationships is crucial for planning orthodontic treatment. Overbite depth indicator (ODI) and anteroposterior dysplasia indicator (APDI) had been introduced in the past for assessment of vertical and sagittal jaw relationships, respectively. OBJECTIVE:: The objectives of this study were to evaluate the reliability of ODI and APDI in overbite and Angle malocclusions, as well as assess their diagnostic reliability among males and females of different age groups. MATERIAL AND METHODS:: This study was conducted using pretreatment dental casts and lateral cephalograms of 90 subjects. For ODI, subjects were divided into three groups based on overbite (normal overbite, open bite and deep bite). Likewise, the same subjects were divided for APDI into three groups, based on Angle's malocclusion classification (dental Class I, II and III malocclusions). Mann-Whitney U test was applied for comparison of study parameters regarding sex and different age groups. The mean values of ODI and APDI were compared among study groups by means of Kruskal-Wallis and post-hoc Dunnet T3 tests. The receiver operating characteristic (ROC) curve was applied to test diagnostic reliability. RESULTS:: Insignificant differences were found for ODI and APDI angles, particularly in regards to sex and age. Significant intergroup differences were found in different overbite groups and Angle's classification for ODI and APDI, respectively (p < 0.001). ROC showed 91% and 88% constancy with dental pattern in ODI and APDI, respectively. CONCLUSIONS:: ODI can reliably differentiate deep bite versus normal overbite and deep bite versus open bite. APDI can reliably differentiate dental Class I, II and III malocclusions.

Reliability of overbite depth indicator (ODI) and anteroposterior dysplasia indicator (APDI) in the assessment of different vertical and sagittal dental malocclusions: a receiver operating characteristic (ROC) analysis

ABSTRACT Introduction: Differential diagnosis of skeletal and dental relationships is crucial for planning orthodontic treatment. Overbite depth indicator (ODI) and anteroposterior dysplasia indicator (APDI) had been introduced in the past for assessment of vertical and sagittal jaw relationships, respectively. Objective: The objectives of this study were to evaluate the reliability of ODI and APDI in overbite and Angle malocclusions, as well as assess their diagnostic reliability among males and females of different age groups. Material and Methods: This study was conducted using pretreatment dental casts and lateral cephalograms of 90 subjects. For ODI, subjects were divided into three groups based on overbite (normal overbite, open bite and deep bite). Likewise, the same subjects were divided for APDI into three groups, based on Angle's malocclusion classification (dental Class I, II and III malocclusions). Mann-Whitney U test was applied for comparison of study parameters regarding sex and different age groups. The mean values of ODI and APDI were compared among study groups by means of Kruskal-Wallis and post-hoc Dunnet T3 tests. The receiver operating characteristic (ROC) curve was applied to test diagnostic reliability. Results: Insignificant differences were found for ODI and APDI angles, particularly in regards to sex and age. Significant intergroup differences were found in different overbite groups and Angle's classification for ODI and APDI, respectively (p < 0.001). ROC showed 91% and 88% constancy with dental pattern in ODI and APDI, respectively. Conclusions: ODI can reliably differentiate deep bite versus normal overbite and deep bite versus open bite. APDI can reliably differentiate dental Class I, II and III malocclusions.

RESUMO Introdução: o diagnóstico diferencial das relações esqueléticas e dentárias é essencial para o plano de tratamento ortodôntico. O indicador de profundidade da sobremordida (ODI)) e o indicador de displasia anteroposterior (APDI) foram desenvolvidos, no passado, para avaliação das relações verticais e sagitais dos maxilares, respectivamente. Objetivo: o objetivo desse estudo foi avaliar a confiabilidade do ODI e do APDI em diferentes sobremordidas e más oclusões de Angle, bem como verificar sua confiabilidade diagnóstica em homens e mulheres de diferentes grupos etários. Métodos: esse estudo foi conduzido utilizando-se modelos de estudo e radiografias cefalométricas laterais pré-tratamento de 90 indivíduos. Para o ODI, os indivíduos foram divididos em três grupos, com base na sobremordida (sobremordida normal, mordida aberta, mordida profunda). Ainda, para avaliação do APDI, esses mesmos indivíduos foram divididos em três grupos baseados na classificação de Angle para as más oclusões (Classes I, II e III dentárias). O teste U de Mann-Whitney foi aplicado para comparar os parâmetros estudados, quanto ao sexo e diferentes grupos etários. Os valores médios do ODI e do APDI foram comparados entre os grupos estudados por meio dos testes de Kruskal-Wallis e post-hoc T3 de Dunnett. A curva ROC (receiver operating characteristic) foi aplicada para testar a confiabilidade do diagnóstico. Resultados: diferenças não significativas foram encontradas para os ângulos ODI e APDI, particularmente em relação ao sexo e à idade. Diferenças significativas foram encontradas entre os grupos com diferentes sobremordidas e diferentes más oclusões de Angle, para o ODI e para o APDI, respectivamente (p < 0,001). A ROC mostrou 91% e 88% de concordância com o padrão dentário, para o ODI e APDI, respectivamente. Conclusões: o ODI mostrou-se confiável para diferenciar entre a mordida profunda e a sobremordida normal, e entre a mordida profunda e a mordida aberta. O APDI é confiável para se diferenciar entre as más oclusões dentárias de Classes I, II e III.

Influence of initial occlusal severity on time and efficiency of Class I malocclusion treatment carried out with and without premolar extractions.

INTRODUCTION: The aim of this retrospective study was to compare the occlusal outcomes, duration and efficiency of Class I malocclusion treatment carried out with and without premolar extractions in patients with different degrees of initial malocclusion severity. METHODS: Complete records of 111 patients were obtained and divided into two groups: Group 1 consisted of 65 patients at an initial mean age of 13.82 years old treated with four premolar extractions; whereas Group 2 consisted of 46 patients at an initial mean age of 14.01 years old treated without extractions. Two subgroups were obtained from each group (1A, 1B, 2A and 2B) with different degrees of malocclusion severity according to the initial values of PAR index. Compatibility was assessed using chi-square and t-tests. The subgroups were compared by means of Analysis of Variance (ANOVA). The variables that might be related to treatment duration and efficiency were assessed using the multiple linear regression analysis. RESULTS: Initial malocclusion severity was positively related to the amount of occlusal correction and consequently to a higher efficiency index. Moreover, extraction protocol showed a positive relationship with treatment duration and a negative relationship with treatment efficiency. CONCLUSION: Extraction and non-extraction protocols for correction of Class I malocclusion provide similar satisfactory results; however, the extraction protocol increases the overall treatment duration. Orthodontic treatment is more efficient in cases with high initial malocclusion severity treated with a non-extraction protocol.

Influence of initial occlusal severity on time and efficiency of Class I malocclusion treatment carried out with and without premolar extractions

INTRODUCTION: The aim of this retrospective study was to compare the occlusal outcomes, duration and efficiency of Class I malocclusion treatment carried out with and without premolar extractions in patients with different degrees of initial malocclusion severity. METHODS: Complete records of 111 patients were obtained and divided into two groups: Group 1 consisted of 65 patients at an initial mean age of 13.82 years old treated with four premolar extractions; whereas Group 2 consisted of 46 patients at an initial mean age of 14.01 years old treated without extractions. Two subgroups were obtained from each group (1A, 1B, 2A and 2B) with different degrees of malocclusion severity according to the initial values of PAR index. Compatibility was assessed using chi-square and t-tests. The subgroups were compared by means of Analysis of Variance (ANOVA).The variables that might be related to treatment duration and efficiency were assessed using the multiple linear regression analysis. RESULTS: Initial malocclusion severity was positively related to the amount of occlusal correction and consequently to a higher efficiency index. Moreover, extraction protocol showed a positive relationship with treatment duration and a negative relationship with treatment efficiency. CONCLUSION: Extraction and non-extraction protocols for correction of Class I malocclusion provide similar satisfactory results; however, the extraction protocol increases the overall treatment duration. Orthodontic treatment is more efficient in cases with high initial malocclusion severity treated with a non-extraction protocol. .

INTRODUÇÃO: o objetivo desse estudo retrospectivo foi comparar os resultados oclusais, o tempo e o grau de eficiência do tratamento da má oclusão de Classe I realizado com e sem extrações em pacientes que apresentavam diferentes tipos de severidade oclusal inicial. MÉTODOS: a amostra foi composta pelas documentações de 111 pacientes, divididas em dois grupos: Grupo 1 (n = 65), com idade inicial média de 13,82 anos, tratados com extrações; Grupo 2 (n = 46), com idade inicial média de 14,01 anos, tratados sem extrações. De cada grupo, foram obtidos dois subgrupos (1A, 1B, 2A e 2B) com severidades oclusais diferentes (alta e baixa), de acordo aos valores iniciais do índice PAR. A avaliação da compatibilidade foi realizada por meio do teste qui-quadrado e do teste t. Os subgrupos foram comparados por meio da análise de variância (ANOVA) e foi realizada a análise de regressão linear múltipla para avaliação das variáveis que poderiam estar relacionadas com o tempo e com a eficiência do tratamento. RESULTADOS: a severidade oclusal inicial esteve diretamente relacionada à quantidade de sua correção e, consequentemente, à obtenção de um maior índice de eficiência; por outro lado, a utilização do protocolo de extrações de pré-molares mostrou uma relação direta com o tempo de tratamento e inversa com a eficiência do tratamento. CONCLUSÃO: no tratamento da má oclusão de Classe I, podem ser obtidos resultados oclusais satisfatórios com uma maior quantidade de correção das alterações oclusais nos casos com maior severidade inicial, e um maior tempo de tratamento quando o tratamento envolve extrações dentárias. .

Effects of intrusion combined with anterior retraction on apical root resorption.

This study evaluated the influence of intrusion mechanics combined with anterior retraction on root resorption of the maxillary incisors. A sample of 56 patients was divided into two groups: group 1 comprised 28 patients (12 females and 16 males), presenting with an increased overjet and deep overbite (6.48 and 4.78 mm, respectively) treated with reverse curve of Spee intrusion mechanics and group 2 comprised 28 patients (12 females and 16 males) with an increased overjet of 5.67 mm and a normal overbite of 1.12 mm. The initial mean ages for groups 1 and 2 were 13.41 and 13.27 years, respectively. Pre- (T1) and post- (T2) treatment periapical radiographs were used to evaluate root resorption. The groups were compared using the Mann-Whitney U-test. Correlation between root resorption and tooth movement was investigated with Spearman's correlation coefficient. The subjects in group 1 had statistically greater root resorption (P < 0.05) than those in group 2. The initial overbite severity and the amount of correction had significant positive correlations with root resorption (r = 0.324 and r = 0.320, respectively). The combination of anterior retraction with intrusive mechanics causes more root resorption than anterior retraction of the maxillary incisors alone.