Table 2: Comparison of mean difference between Haavikko's, Demirjian's and Willems methods of dental age estimation with chronologic age

		Mean		Std. deviation		Mean difference in years		Standard error		Paired t-test, p-value		Pearson's correlation coefficient
												r		p-value
Chronological age		12.27		1.69		–1.95		0.12		0.001*		0.69		0.001*
Haavikko's method		10.31		1.04
Chronological age		12.27		1.69		0.55		0.08		0.001*		0.88		0.001*
Demirjian's method		12.89		1.81
Chronological age		12.27		1.67		–0.20		0.12		0.11		0.73		0.001*
Willems method		12.06		1.80

*Highly significant