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Advisor(s)
Abstract(s)
Introdução: O diagnóstico precoce é essencial para o tratamento das discrepâncias dentomaxilares na dentição mista. Este estudo teve como objetivo desenvolver métodos de previsão do tamanho dentário na dentição mista precoce, aplicáveis a partir dos seis anos de idade dentária.
Materiais e métodos: Modelos de gesso de 125 indivíduos foram digitalizados com o scanner iTero 5D Element Plus™. O tamanho mesiodistal dos dentes foi medido com o software MeditLink, em ambas as arcadas. Equações de regressão linear utilizando sete combinações diferentes dos primeiros seis dentes permanentes erupcionados foram desenvolvidas para prever o espaço total e anterior necessário para os dentes permanentes não erupcionados, na maxila e mandíbula. O desempenho preditivo de várias combinações de dentes (MP1-MP7) foi avaliado através do desenvolvimento de uma equação de regressão linear simples para cada um dos métodos. Uma subamostra de 30 indivíduos diferentes foi usada para realizar um estudo
de validação.
Resultados: Os caninos inferiores apresentaram os maiores valores de dimorfismo sexual e os incisivos laterais superiores de variabilidade de tamanho. No geral, as equações específicas por sexo tiveram um desempenho idêntico às equações combinadas. A previsão da soma dos incisivos laterais inferiores, caninos e pré-molares (ΣMn2,3,4,5) apresentou os maiores valores de correlação para as equações combinadas tanto na amostra de estudo (r=0.808) como de validação (r=0.630). Globalmente MP2 (Σ31,41,36,46), MP3 (Σ31,41,16,26) e MP5 (Σ31,41) apresentaram as correlações mais altas e os erros médios mais baixos.
Conclusão: A previsão do tamanho dos dentes permanentes não erupcionados pode ser realizada em idades mais precoces com precisão semelhante às previsões, em idades posteriores, usando o método de Tanaka-Johnston. As equações específicas para cada sexo apresentaram resultados comparáveis à equação combinada, pelo que recomendamos o usoclínico desta última. Este estudo destaca a importância de validar as equações de previsão do tamanho dentário numa amostra diferente.
Introduction: Prediction of tooth size/arch length discrepancy during the early mixed dentition phase might aid in preventing future development of malocclusion. The present study aimed to establish an early mixed dentition prediction method applicable from six years of dental age. Materials and methods: Study models of 125 Portuguese individuals (61 males and 64 females, with a mean age of 20.2±6.6 and 21.6±7.3, respectively) were scanned with the iTero 5D Element Plus™ scanner. The mesiodistal width of each tooth in both arches was measured using MeditLink software. Linear regression equations using seven different combinations of the erupted permanent teeth were developed to predict the total and anterior space needed for the unerupted permanent teeth in the maxilla and mandible. The predictive performance of various combinations of the erupted teeth (prediction methods MP1 to MP7) was assessed by developing a simple linear regression equation for each method. A subsample of 30 different individuals was collected to perform a validation study. Results: Lower canines showed the most significant sexual dimorphism, and upper lateral incisors had the wider size variability. Overall, sex-specific equations performed identically to the combined equations. Prediction of the sum of mandibular lateral incisor, canine and premolars (ΣMn2,3,4,5) showed the highest correlation values for the combined equations in both the study (r=0,808) and the validation (r=0,630) samples. Overall MP2 (Σ31,41,36,46), MP3 (Σ31,41,16,26) and M5 (Σ31,41) showed higher correlations and lower mean errors. Conclusion: The size of unerupted permanent teeth could be predicted at an earlier age, when the lower central incisors are erupted with similar accuracy as later predictions using the Tanaka-Johnston equations. Sex-specific equations showed comparable results to the combined equation; therefore, we recommend the clinical use of the latter. This study highlights the importance of validating tooth size prediction equations on a different group of individuals.
Introduction: Prediction of tooth size/arch length discrepancy during the early mixed dentition phase might aid in preventing future development of malocclusion. The present study aimed to establish an early mixed dentition prediction method applicable from six years of dental age. Materials and methods: Study models of 125 Portuguese individuals (61 males and 64 females, with a mean age of 20.2±6.6 and 21.6±7.3, respectively) were scanned with the iTero 5D Element Plus™ scanner. The mesiodistal width of each tooth in both arches was measured using MeditLink software. Linear regression equations using seven different combinations of the erupted permanent teeth were developed to predict the total and anterior space needed for the unerupted permanent teeth in the maxilla and mandible. The predictive performance of various combinations of the erupted teeth (prediction methods MP1 to MP7) was assessed by developing a simple linear regression equation for each method. A subsample of 30 different individuals was collected to perform a validation study. Results: Lower canines showed the most significant sexual dimorphism, and upper lateral incisors had the wider size variability. Overall, sex-specific equations performed identically to the combined equations. Prediction of the sum of mandibular lateral incisor, canine and premolars (ΣMn2,3,4,5) showed the highest correlation values for the combined equations in both the study (r=0,808) and the validation (r=0,630) samples. Overall MP2 (Σ31,41,36,46), MP3 (Σ31,41,16,26) and M5 (Σ31,41) showed higher correlations and lower mean errors. Conclusion: The size of unerupted permanent teeth could be predicted at an earlier age, when the lower central incisors are erupted with similar accuracy as later predictions using the Tanaka-Johnston equations. Sex-specific equations showed comparable results to the combined equation; therefore, we recommend the clinical use of the latter. This study highlights the importance of validating tooth size prediction equations on a different group of individuals.
Description
Dissertação para obtenção do grau de Mestre no Instituto Universitário Egas Moniz
Keywords
Dentição mista precoce Previsão do tamanho dentário Medições digitais Discrepância dento-maxilar