Knowledge of deciduous crown formation times is useful in forensic anthropology and when aging juvenile remains from an archaeological context. Until now, histological techniques for calculating enamel formation times in deciduous teeth have been completely dependent on being able to visualise clear daily incremental markings. In the first part of this study we took twenty deciduous teeth where daily incremental markings were easily visible on both aspects of the crown and used these as the basis for generating regression equations to predict enamel formation times. We were then able to use these regression equations to calculate deciduous crown formation times in a further fifty deciduous teeth where it was not possible to see daily increments. We present here new data for deciduous crown formation times based on these regression equations. In the second part of this study these regression formulae were applied blind to teeth from two individuals with known medical histories. The formulae were able to successfully determine the times of prenatal and postnatal enamel formation relative to the neonatal line and also to correctly estimate the ages at which accentuated 'stress lines' occurred during the period of deciduous crown formation.

A method of calculating human deciduous crown formation times and of estimating the chronological ages of stressful events occurring during deciduous enamel formation (vol 22, pg 127, 2014)

OBJECTIVES The Osteological Paradox posits that skeletal lesions may differentially be interpreted as representing resilience or frailty However, specific consideration of the etiologies and demographic distributions of individual skeletal indicators can inform the criteria on which to differentiate stress, frailty, and resilience Adopting a life history approach and adaptive plasticity model, this study proposes a framework for the analysis and interpretation of a commonly reported skeletal lesion, cribra orbitalia, which considers the underlying mechanisms of the condition, the clinical and epidemiological literature relating to anemia and malnutrition, and the bioarcheological evidence MATERIALS AND METHODS Data were extracted from the European (n = 33 populations) and American (n = 19 populations) modules of the Global History of Health Project Kaplan-Meier and Cox regression analyses were applied, where time was the age-at-death, and the factor or covariate was presence or absence of cribra orbitalia RESULTS Of 37 samples that produced significant results, 21 demonstrated a change in relationship when the subadults were excluded from analysis When subadults were included, individuals with cribra orbitalia present had statistically significant lower survival time With subadults excluded, the relationship either became nonsignificant or was reversed DISCUSSION We demonstrate that in many cases the inclusion of subadults in analysis impacts upon the apparent mortality associated with cribra orbitalia Examining cribra orbitalia in children and adults has two separate goals: in children, to determine the prevalence and risk of death associated with active lesions and stress; and in adults, to determine whether childhood health assaults that cause cribra orbitalia are associated with frailty or resilience

https://onlinelibrary.wiley.com/doi/pdf/10.1002/ajpa.24091

A paleoepidemiological approach to the osteological paradox: Investigating stress, frailty and resilience through cribra orbitalia

Teeth contain an incremental record of their growth in the form of periodic growth markings that are literally embodied within the structure of enamel. These can be revealed when ground sections of teeth are prepared for transmitted light microscopy. This chapter sets out one method for estimating the time taken to form the crowns of permanent teeth. First, the daily rates of enamel formation are estimated at three positions within the crown close to the enamel dentine junction (EDJ). Then a 200 μm length along an enamel prism that take ∼80 days to form is followed out from the EDJ at the dentine horn. From this point a line is then tracked back along the direction of the oblique striae of Retzius that are contained within enamel to a lower position further along the EDJ. This procedure is repeated until the cervix of the tooth is reached. The total time for enamel formation is estimated by summing the number of 80 day segments traced out.

A histological method that can be used to estimate the time taken to form the crown of a permanent tooth.

Insights on patterns of developmental disturbances from the analysis of linear enamel hypoplasia in a Neolithic sample from Liguria (northwestern Italy).

Enamel neonatal line thickness in deciduous teeth of Australian children from known maternal health and pregnancy conditions.

Use of dental microstructure to investigate the role of prenatal and early life physiological stress in age at death

Synchrotron radiation micro X-Ray Fluorescence (SR-μXRF) elemental mapping of ancient hair: Metals and health at 3rd millennium BCE Shahr-i Sokhta, Iran

Farzad Foruzanfar

Papers

Use of dental microstructure to investigate the role of prenatal and early life physiological stress in age at death

Synchrotron radiation micro X-Ray Fluorescence (SR-μXRF) elemental mapping of ancient hair: Metals and health at 3rd millennium BCE Shahr-i Sokhta, Iran

First permanent molars with accentuated line patterns: Assessment of childhood health in an urban complex of the fifth millennium before the present.