A comparison of the validity of the Demirjian, Willems, Nolla and Häävikko methods in determination of chronological age of 5-15 year-old Indian children.

BACKGROUND: Demirjian's method has been the most popular and extensively tested radiographic method of age estimation. More recently, Willems' method has been reported to be a better predictor of age. Nolla's and Häävikko's methods have been used to a lesser extent. Very few studies have compared all four methods in non-Indian and Indian populations. Most Indian research is limited by inadequate sample sizes, age structures and grouping and different approaches to statistical analysis. AIM: The present study aimed to evaluate and compare the validity of the Demirjian, Willems, Nolla and Häävikko methods in determination of chronological age of 5 to 15 year-old Indian children. DESIGN: In this cross-sectional observational study, four methods were compared for validity in estimating the age of 1200 Indian children aged 5-15 years. RESULTS: Demirjian's method overestimated age by +0.24 ± 0.80, +0.11 ± 0.81 and +0.19 ± 0.80 years in boys, girls and the total sample, respectively. With Willems' method, overestimations of +0.09 ± 0.80, +0.08 ± 0.80 and +0.09 ± 0.80 years were obtained in boys, girls and the total sample, respectively. Nolla's method underestimated age by -0.13 ± 0.80, -0.30 ± 0.82 and -0.20 ± 0.81 years in boys, girls and the total sample, respectively. Häävikko's method underestimated age by -0.17 ± 0.80, -0.29 ± 0.83 and -0.22 ± 0.82 years in boys, girls and the total sample, respectively. Statistically significant differences were observed between dental and chronological ages with all methods (p < 0.001). Significant gender-based differences were observed with all methods except Willems' (p < 0.05). Gender-specific regression formulae were derived for all methods. CONCLUSION: Willems' method most accurately estimated age, followed by Demirjian's, Nolla's and Häävikko's methods. All four methods could be applicable for estimating age in the present population, mean prediction errors being lower than 0.30 years (3.6 months).

Willems I VS Willems II: A comparative study of accuracy in 5-15 year old Indian children.

BACKGROUND: Studies testing the Willems method of age estimation with gender-specific scores on different population groups have reported consistently more accurate results over other methods. Not enough is known about the validity of Willems non-gender specific scores. AIM: The present study aimed to compare the accuracy of the Willems I (gender-specific scores) and Willems II methods (non-gender-specific scores) in the age estimation of 5-15 year-old Indian children. DESIGN: In this cross-sectional observational study, the Willems I and II methods were tested and compared for accuracy in estimating the age of 1200 Indian children aged 5-15 years. RESULTS: The mean differences between dental age calculated by the Willems I method and chronological age were +0.09±0.80 years, +0.08±0.80 years and +0.09±0.80 years for boys, girls and the total sample, respectively. With the Willems II method, the values were -0.06±0.80 years, +0.11±0.79 years and +0.01±0.80 years for boys, girls and the total sample, respectively. Both methods did not show any statistically significant differences between dental and chronological ages for either gender or the total sample (p>0.05). CONCLUSION: The Willems I method was more accurate in predicting age of boys, while the Willems II method was more accurate in girls in the present study, but not significantly so. Both methods are appropriate for use in this population.

Staging of third molar development in relation to chronological age of 5-16 year old Indian children.

BACKGROUND: The usefulness of the developmental status of the third molar has been studied in assessment of the chronological age of adolescents in whom the development of the other permanent teeth is nearly complete. However, little is known about the timing and pattern of third-molar development in the Indian population. AIM: This study aimed to stage the third molar development in relation to chronological age of 5-16year old Indian children. DESIGN: In this cross-sectional observational study, the status of third molar development in relation to chronological age of 1139 Indian children aged 5-16 years was evaluated radiographically, using Orhan's modification of Demirjian's method. RESULTS: The frequency of occurrence of the third molars varied from 47% to 70%. Crypt formation, crown completion and root completion occurred as early as 5.4, 8.7 and 15.0 years, respectively. No significant differences based on gender or side were observed in third-molar development (p>0.05). For most stages, maxillary third molars were slightly more advanced than their mandibular counterparts (p>0.05). CONCLUSION: Considering the high degree of variability observed in third molar genesis and development, the usefulness of this tooth in age determination studies may be very limited in the age group studied.