Introduction

Tooth formation is widely used to assess maturity and predict age. In clinical dentistry, this information aids in diagnosis and treatment planning.₁ The continuous patterns of tooth development can be observed on a longitudinal series of radiographs and various mineralization stages.₂,₃,₄,₅,₆ A number of methods have been proposed to determine dental age,₇,₈,₉ but, the system developed by Demirijian has gained wide acceptance.₉

During developmental stages particularly in root formation, a notable difference between sexes arises with females being advanced when compared with males.₁₀,₁₁ The aim of this study was to determine age from open and closed apices of teeth, and derived a standard regression equation from them.

Material and Methods

Sample: The orthopantomographs sample of 435 healthy children (218 boys: 217 girls) aged between 4-16 years (table 1) was selected. Panoramic radiographs that were unclear or that showed hypodentia, gross pathology and previous orthodontic treatment were excluded. The chronological age for each subject was calculated by subtracting the data of the radiograph from the date of birth.

Study Design: This was a retrospective cross-sectional study. Good quality digital panoramic radiographs taken for this study during the course of diagnosis and treatment.

Dental Age Estimation

Results

The ANOVA results (table II) show that gender and the variables x3 (Canine), S, N0 and first order interaction between S and N0 contributed significantly to the fit and fielding the following regression equation:

Age = 7.083+0.493G+0.931x3-0.854S+0.693N0-0.185S N0 Equation (1)

G variable is 1 for boys and 0 for girls. Correlation coefficients between age and morphological variables were statistically significant and negative.

Figure 1

Table 1: Different groups of age and gender in the study

Figure 2

Table 2: Regression analysis predicting chronological age from the predictors

Figure 3

Figure 1: Parameters of Study

Discussion and Conclusion

Chronological age, as recorded by registration of birth date, is referred to throughout an individual's life. This information is relevant in medical and dental practice for evaluating developmental progress, for educational purposes and in legal maters, particularly in application of criminal law.₉,₁₀ Various studies have reported that morphological measurements can be reliably made in orthopentomographs provided that some corrections are made to take into account the individual variability of tooth size and the differences in magnification of radiographs and angulation between x-ray beam and film.¹² In this study, to obtain an estimated age in north Indian children aged between 4 to 16 years old was obtained used measurements of the open apices of the (mean) of the seven permanent mandibular teeth. While one study have taken into account only left seven permanent mandibular teeth. The open apices in the present study showed a significant correlation with age, but only x3 contributed significantly to fit, while the other teeth entered the model equation while this consistent with previous study except x5 (Second premolar) contributed significantly to fit.₉,₁₀ This may be due to different genetic factor, environmental factors, nutritional factors and geographical factors.₁₀,₁₁ The present regression equation I is derived for age estimation from children. This equation may be used as a diagnostic tool for age estimateion in children, where in medicolegal cases and clinical dentistry.

Acknowledgement

Correspondence to

Dr. Balwant Rai (Editor In Chief Internet Journal of Dental Science) E-mail : drbalwantraissct@rediffmail.com Mobile No. :0091-9812185855