Does the crypt: tooth ratio in the developing tooth correlate with chronological age in children?—a novel, radiographic, cross-sectional pilot study using ImageJ tools

Abstract

Abstract Background The bony cavity known as the crypt encloses the developing tooth, the size of which is influenced by the tooth movements during various phases of tooth eruption. The radiographic observations have revealed that the size of the crypt decreases as the root formation continues. The present study was conducted to assess the relationship between the crypt to tooth ratio (CTR) and the chronological age in children in the age range of 4 to 16 years using their digital panoramic radiographs (OPGs). The ImageJ tools were used to calculate the area of the bony crypt and the area of the developing mandibular second molar from 145 OPGs. The ratio between the area of the crypt and the area of the calcified portion of the tooth was obtained and compared with the calendric age (CA) to develop a regression model for age estimation. Results There was a significant negative correlation between the chronological age and the CTR values (r= −0.898, p<0.001) in all the age groups. The derived regression formula was age = 17.192–3.855 (CTR) with an r 2 value of 0.807 and a standard error of estimate (SEE) being 1.385. The derived formula was tested using 52 OPGs from a different set of patients in the same age group. The mean chronological age of the test sample was 9.57 years (± 3.42), their mean estimated age (EA) was 8.50 years (± 3.25), and the difference was statistically significant (p<0.001). A difference of more than 1 year was observed in 69% of boys and 54% of girls. Conclusions This method is an attempt to correlate the crypt to tooth ratio of developing the second molar tooth with the chronological age. A large sample study is required to validate this novel technique of age estimation in children.

Keywords

• Bony crypt
• Crypt to tooth ratio
• Mandibular second molar
• Age estimation
• Orthopantomogram