ABSTRACT
Objective To study the accuracy of Nolla method for age estimation of Northern Chinese Han children aged between 5.00 and 14.99 years based on original transformation tables and multiple regression model. Methods A total of 2 000 orthopantomographs （OPGs） were collected from the Hospital of Stomatology, Xi'an Jiaotong University, including 1 000 males and 1 000 females. Development stage of 7 left mandibular permanent teeth （except third molars） was assessed based on Nolla method, then age estimation was conducted through transformation tables and multiple regression model, respectively. Firstly, the development stage results of 7 permanent teeth were added up and the estimated age was obtained through the original transformation tables. Secondly, 80% of the samples （80 males and 80 females in each age group） were randomly selected from 2 000 OPGs as the train set. The chronological age of the selected patients was taken as the dependent variable, while gender and the development stage results of 7 permanent teeth were taken as the independent variable to establish multiple regression model. The remaining 20% of the samples were substituted into the model as the test set, to verify the accuracy of age estimation by multiple regression model. Results Mean chronological ages of males and females were 10.03±0.09 years and 10.01±0.09 years, respectively. The age estimated by original transformation tables showed an overestimation for males （0.18 years on average） and an underestimation for females （0.02 years on average）, with mean absolute error （MAE） of 0.94 years and 0.97 years, respectively. While the results by multiple regression model showed that males were overestimated by 0.06 years on average and females were underestimated by 0.02 years on average. The MAE was 0.66 years and 0.77 years, respectively. Conclusion The Nolla method is suitable for age estimation of Northern Chinese Han children. Compared with the original transformation tables method, the multiple regression model is more accurate for age estimation.
Subject(s)
Adolescent , Child , Child, Preschool , Female , Humans , Male , Age Determination by Teeth , Asian People , China , Molar, Third , Radiography, PanoramicABSTRACT
RESUMEN: Objetivo: El propósito de este estudio fue comparar tres métodos de estimación de la edad dental (ED) con fines forenses. Material y métodos: Se seleccionaron 512 radiografías panorámicas de sujetos de Maracaibo, estado Zulia, Venezuela, de ambos sexos (272 hembras y 240 varones), con edades cronológicas (EC) entre 6-18 años. Se asignaron los estadios de maduración propuestos por Nolla, Moorrees et al y Demirjian et al a siete dientes mandibulares permanentes del lado izquierdo, la ED fue calculada de acuerdo con la metodología de cada autor. Se obtuvo la EC en la cual se observaron los diferentes estadios de maduración, así como las diferencias de media entre la EC y la ED estimada por cada método mediante un test de Student para muestras relacionadas. Resultados: En general, las hembras alcanzaron los estadios de maduración a edades más tempranas que los varones. Se evidenció en el total de la muestra, una sobreestimación de la edad para el método de Demirjian et al (-0.14 ± 1.45), mientras que para el de Nolla y Moorrees et al se observó una subestimación, esta subestimación fue mayor para el método de Moorrees et al (2.63 ± 2.09) que para el de Nolla (0.42 ± 1.38), siendo que las diferencias encontradas entre la EC y la ED fueron estadísticamente significativas. Conclusión: Se determinó que para el total de la muestra, el método de Demirjian et al fue el más preciso.
ABSTRACT: Objective: The purpose of the present study was to compare three methods for calculation of dental age (DA) to be used for forensic purposes. Material and methods: 512 panoramic X-rays of subjects of both genders living in Maracaibo, State of Zulia, Venezuela were selected (272 females, 240 males). Selected subjects were in the 6-18 years chronological age (CA) range. Maturation stages of Nolla, Moorrees et al and Demirjian et al were assigned to seven permanent teeth of the left side, and DA was calculated according to methodology of each author. CA was obtained where different stages of maturation were observed, as well as mean difference between DA and CA as calculated with each method were obtained with a t student test for related samples. Results: In general, females reached maturation stages at earlier ages than males. The total sample revealed age over-estimation for the Demirjian method (-0.14 ± 1.45), whereas, a sub-calculation was observed for the Nolla and Moorrees et al method. This under-estimation was greater for the Moorrees at al method (2.63 ± 2.09) when compared to Nolla method (0.42 ± 1.38) and differences between DA and CA were found to be statistically significant. Conclusion: In the total studied sample, it was determined that Demirjian et al method was the most accurate.
ABSTRACT
Objetivo. Determinar qué método, Demirjian o Nolla, es más preciso en la determinación de la edad en niños peruanos de 4 a 15 años. Material y métodos. Se evaluaron 59 radiografías panorámicas, 25 del sexo masculino y 34 del femenino; se determinó la edad dental según los métodos mencionados, y posteriormente se comparó esta con la edad cronológica. Resultados. Se encontró una diferencia significativa entre la edad dental y la edad cronológica determinada con método Demirjian; la edad fue sobrestimada en 0.94 años. Con el método Nolla no se encontró una diferencia significativa entre ambas edades; la edad fue subestimada en -0.24 años. Conclusiones. El método Nolla es más preciso para estimar la edad dental, según la muestra de estudio empleada, por no haber diferencias significativas entre la edad dental y la edad cronológica.
Objective. To determine which method, Demirjian or Nolla, is more accurate in determining the age in peruvian children of 4 to 15 year old. Materials and methods. 59 panoramic radiographs were evaluated, 25 of male and 34 of female; dental age was determined according to both methods, and then compared this one with chronological age. Results. When using the Demirjian method a significant difference between dental age and chronological age was found, the age was overestimated in 0.94 years. With the Nolla method we found no significant difference between the two ages, age was underestimated -0.24 years. Conclusions. The Nolla method is more accurate to estimate the dental age, according to the study sample used, there is no significant difference between dental age and chronological age.