This was a cross-sectional, observational study (June–September 2018). The objectives of this study were thus 1) to assess the relationship of bone age with chronological age as assessed by different methods (GP, GR, and TW3) in healthy Indian children and to study differences in genders and 2) to assess which of the three methods of BA assessment is most suitable for Indian children. Also, the wider the range of values analyzed (in our study 2–16.5 years), the greater is the correlation obtained. Correlation coefficients measure the strength of association between two variables and not the agreement between them. In addition, most of the studies done worldwide comparing different methods of BA estimation have used correlation analysis. However, only a handful of Indian studies have compared GP atlas and TW methods of estimation, and these studies were based on the TW-2 method and were performed several decades ago. This makes the use of the TW-3 method of BA estimation an attractive option in children of different ethnicities (Indian children), as, during its development, Asian children’s bones were also included. This has been discussed in a systematic review, which showed that the GP atlas could be imprecise and should be used with caution in Asian/African children. Hence, there are concerns regarding its accuracy and reliability in different ethnic populations. TW method, in contrast to other methods, is not based on pattern matching rather, it is based on the stage of maturity of epiphyses of long and short bones of the hand or carpal bones depending on the method used respectively (13 bone method or 20 bone method, respectively).Īlthough GP atlas is the most commonly used method of BA estimation worldwide, it is based only on Caucasian children and the data are over 7 decades old. The TW method was derived from British children in 1950 and was revised as the TW-3 method in 2001 (inclusion of children from different ethnic populations and abolition of 20 bone score). GR atlas, a relatively new method developed in 2005, was produced by the creation of artificial, idealized, averaged sex, and age-specific images of skeletal development. GP Atlas was prepared from 1,000 Caucasian children of North European descent born between 19 in the USA. The two major methods of BA assessment used commonly are i) Atlas method and ii) Scoring of epiphyses method. The other applications of BA include height prediction and estimation of age in children seeking asylum in other countries and in competitive sports where chronological age (CA) may be unknown. Hence, it seems reasonable to recommend the use of the TW-3 method for BA estimation in the Indian population till an Indian standard bone age atlas is developed.īone age (BA) is a measure of the skeletal maturity of an individual and tells us about the growth potential of a child. Conclusions:Īmong the three methods (GP, GR, and TW-3), the BAs estimated by the TW-3 method were closest to CAs. In Indian girls, however, the BA was underestimated till the pubertal growth spurt, after which there was rapid advancement of BA. Interestingly, BA was underestimated in Indian boys irrespective of the method used. The same results were obtained when root mean square (RMS) deviations were computed. However, in pubertal boys, the GR atlas method was most suitable ( P < 0.05). Using the test of proportions, the TW-3 method was most suitable overall ( P 0.1), and pubertal girls ( P < 0.05). For purpose of deciding which method of BA was most suitable in our cohort, a test of proportions and root mean square (RMS) deviations were computed. X-rays of 851 children (438 boys and 413 girls, aged 2–16.5 years) were analyzed by four independent observers using three different methods of BA estimation (GP, GR, and TW-3). Objectives:ġ) To assess the relationship of BA with chronological age (CA) as assessed by different methods (GP, GR, and TW-3) in healthy Indian children 2) To assess which of the three methods of BA assessment is more suitable in Indian children. Although GP atlas is the most widely used, there are concerns about its accuracy in children of different ethnicities, making the use of the TW-3 method an attractive option in Indian children. There are several methods of bone age (BA) assessment, which include Gruelich-Pyle (GP), Gilsanz-Ratib (GR), and Tanner Whitehouse-3 ( TW-3) methods.

Bone age and chronological age