Accuracy assessment of dental age estimation with the Willems, Demirjian and Nolla methods in Spanish children: Comparative cross-sectional study

Abstract

Background: The objective of this study was to evaluate and compare the validity and accuracy of the Willems, Demirjian and Nolla methods in predicting chronological age in a Spanish ethnicity population. Methods: A sample of 604 orthopantomographs of Spanish children aged 4 to 13 years was evaluated by two independent evaluators. Descriptive statistics were applied to calculate the chronological age and dental age, presenting the mean and standard deviation. The difference between dental age and chronological age was calculated for each method. A positive result indicated an overestimation and a negative figure indicated an underestimation. The Wilcoxon test for paired data and Spearman's correlation coefficient were applied by age groups and sex to compare the chronological age and dental age of each method (that of Willems, Demirjian and Nolla). Statistical tests were performed at a 95% confidence level. Results: The interexaminer agreement was 0.98 (p = 0.00), and the intraexaminer agreement was 0.99 (p = 0.00). The Willems method significantly overestimated the age of boys (0.35 years (0.93)) and girls (0.17 years (0.88)). The Demirjian method significantly overestimated the age of boys (0.68 years (0.95)) and girls (0.73 years (0.94)). The Nolla method significantly underestimated age in boys (0.44 years (0.93)) and girls (0.82 years (0.98)). Conclusions: In the Spanish population, the use of the Demirjian method for legal and medical purposes is frequent. This study reveals that the Willems method is more appropriate due to its greater precision in estimating dental age.

Dental age estimation and accuracy assessment by Demirjian, Nolla and Willems methods in Nepalese children for predicting the chronological age

“…Internationally, using Demirjian method, an overestimation of dental age was found in Brazilians and Croats, 29 Malaysians, 30 Turks, 31 Bangladeshi and British, 32 Indians 2 and Spanish children. 27 The entire sample in this study showed an underestimation in dental age by -1.06 years using Nolla method which is similar with a Nepalese children study 14 and other population studies. 13,27,33,34 Whereas, Nolla's method has also shown overestimation in young children.…”

“…27 The entire sample in this study showed an underestimation in dental age by -1.06 years using Nolla method which is similar with a Nepalese children study 14 and other population studies. 13,27,33,34 Whereas, Nolla's method has also shown overestimation in young children. 2,[35][36][37] Internationally, Nolla method has shown underestimation in the dental age when applied in Brazilians and Croats, 29 Malaysians, 30 Turks, 31 Bangladeshi and British, 32 Indians 38 and Spanish children.…”

“…2,[35][36][37] Internationally, Nolla method has shown underestimation in the dental age when applied in Brazilians and Croats, 29 Malaysians, 30 Turks, 31 Bangladeshi and British, 32 Indians 38 and Spanish children. 27 In this study, Willems method tends to underestimate age by -1.32 yrs in total sample. Comparably, a study done in a small population of Nepalese children also found Willems method to underestimate the dental age.…”

“…25,39 Internationally Willems method, found overestimation in Bangladeshi and British, 32 Indians 38 and in Spanish children. 27 However, a study carried out by Mohammed RB et al 2 also in the Indian population reports underestimation with the Willems method.…”

The Applicable Dental Age Estimation Methods for Children and Adolescents in Indonesia

“…Each of the teeth has an individual score assigned based on the Demirjian calcification stage. The scores of all the individual teeth are added up and converted to the chronological age based on sex [ 26 ].…”