New distance‐based exponential regression method and equations for estimating the chronology of linear enamel hypoplasia (LEH) defects on the anterior dentition

Abstract

Objectives We present a new distance‐based exponential regression approach based on published histological data to refine the objectivity, accuracy, and precision of age estimates of LEH defect formation on the anterior dentition. Methods Published histological data of anterior tooth crown growth for two samples (northern European and southern African) were fitted with exponential trendlines to construct exponential regression equations for each tooth type. A theoretical comparison of the age estimates produced by two commonly used methods (decile chart and linear regression), and those based on the exponential regression equations presented in this article were undertaken. Paired‐samples t‐tests were used to determine whether the estimates obtained by these methods differed significantly. Results Exponential regression equations were able to accurately replicate age estimates produced by the decile‐chart method. For defects that fell precisely on a decile, estimates differed by 1–23 days. Estimates based on the linear regression method were consistently younger by 4.5–16 months. For defects that fell within deciles, the exponential regression equation estimates, when different, were 12 days to 4 months older than those yielded by the decile method. Conclusions By combining currently published histological data on anterior tooth crown growth with a regression approach, it is possible to produce more accurate age estimates than yielded by methods that do not rely on histological data. Furthermore, this approach also greatly improves the objectivity, precision and replicability of results, especially for defects that fall between deciles, when compared to the decile chart method.

Enamel hypoplasia and health conditions through social status in the Roman Imperial Age (First to third centuries, Rome, Italy)

“…The authors developed a decile chart of anterior tooth enamel growth, which took into account the population variations in crown height and the non‐linear enamel growth rate during tooth formation. This method does not provide any indication for premolar teeth, and as also observed by Cares Henriquez and Oxenham (), it is time‐consuming and has precision and replicability problems. Moreover, a comparison of the age of LEH formation between the Reid and Dean's (, ) method and the Goodman and Rose's regression equations () found significant differences ranging from 1 to 4 months (Martin, Guatelli‐Steinberg, Sciulli, & Walker, ; Ritzman, Baker, & Schwartz, ).…”

“Captain of All These Men of Death”: An Integrated Case Study of Tuberculosis in Nineteenth-Century Otago, New Zealand

“…Linear enamel hypoplasia was observed on six anterior teeth (13,12,11,43,42,32) and all but two of these teeth (12 and 11) displayed at least two hypoplastic lines (Fig 4a). The estimated age of the formation of the LEH was between 2-6 years old (Cares Henriquez and Oxenham, 2019).…”

Estimation of age at onset of linear enamel hypoplasia. New calculation tool, description and comparison of current methods

“…A major limitation of both methods is the omission of individual differences in total crown height, which may lead to over‐ or underestimation of age at LEH development. In addition, the Goodman and Song formula is far too simplistic (it has insufficient parameters) to properly describe tooth growth (Henriquez & Oxenham, 2019). Enamel grows in a nonlinear manner, which has necessitated the development of other methods that better reflect the dynamics of tooth crown development (Reid & Dean, 2006).…”

“…Recently, a new method for estimating the age of LEH was proposed by Henriques and Oxenham (2019). It is based on datasets derived by Reid and Dean and the equation a*e (b*x) (where x represents growth deciles, a and b stand for constant coefficients fitted for each tooth type, e is Euler's number).…”