Bruno Foti

New forensic approach to age determination in children based on tooth eruption

The present study proposes equations for age determination both in living and dead children, obtained with the help of stepwise ascending multiple linear regression. The equations should be applied, based on the number of erupted teeth and tooth germs, which were detected on radiographs, during clinical examination and in infant skeletal remains. The proposed equations proved to be efficient just like Demirjians method used as a reference today, and permit age estimation till 20 years of age.

Limits of the Lamendin method in age determination

This study shows that epithelial attachment level, used as age determination criterion in Lamendins method, is not reliable for adults of either sex above the age of 49 years with periodontal diseases in any quadrant. The underestimation of calculated age increases from 7 to 19 years with chronological age. On the other hand, the present paper confirms the pertinence of dentin translucency as an age indicator in Lamendins method.

Three-dimensional Modeling of the Various Volumes of Canines to Determine Age and Sex: A Preliminary Study

Abstract:  Canines are usually used in anthropological and forensic sciences for sex and age determination. The best methods to estimate age are based on secondary dentine apposition, evaluated from periapical X‐rays. The aim of this study was to propose a new method of sex and age estimation using 3D models to obtain more precise predictions using tooth volumes. Fifty‐eight dental CT scans of patients aged 14–74 with a well‐balanced sex ratio composed the sample. One hundred and thirty‐three healthy canines were modeled (Mimics 12.0). The sample was divided into a training sample and a validation sample. An age formula was determined using the “pulp volume/tooth volume” ratio. Sex prediction was adjusted with total volumes. Applying the equations to the validation sample, no significant difference was found between the real and predicted ages, and 100% of the sex predictions were correct. This preliminary study gives interesting results, and this method is worth being tested on a larger data sample.

Estimation of gestational age from tooth germs: Biometric study of DentaScan images.

Abstract:  The few available studies on fetal age estimation concern very small samples, and statistical analysis is sometimes inadequate. In this survey, we used germs of deciduous teeth to estimate fetal age. Forty‐nine fetuses and 40 mandibles were scanned, and observations and measurements were made on DentaScan images. After checking their repeatability and reproducibility (analysis of variance), we defined thresholds using Fisher’s linear discriminant analysis to calculate the probability that a fetus was over or below a predefined age threshold. The forensic threshold which is of particular interest in France is 22 weeks amenorrhea. Relationships between fetal age and deciduous germ measurements were then sought by multiple linear regression. The thresholds gave very good results: 91.84% of good probability for the threshold of 22 weeks amenorrhea with no chance of error. The most precise age evaluation obtained nevertheless gave a range of ±4.6 weeks amenorrhea, so greater accuracy is still needed.

Variabilité intra-individuelle de l'estimation de l'âge au décès adulte à partir des anneaux du cément dentaire

RésuméLa méthode d’estimation de l’âge au décès des adultes par comptage des anneaux du cément dentaire n’est actuellement pas consensuelle car fiabilité et précision diffèrent d’une étude à l’autre. De plus, aucune étude n’a été menée jusqu’à présent sur la variabilité intra-individuelle du cément. À partir d’un échantillon de 51 dents extraites cliniquement sur 15 individus, nous avons quantifié cette variabilité. Les lignes d’incrément ont été comptées sur cinq sections transversales issues du tiers médian radiculaire de chaque dent. Deux estimations de l’âge par dent ont été calculées en tenant compte (1) du nombre maximal de lignes comptées, (2) de la valeur moyenne des comptages. Nos résultats montrent que a) les estimations d’âge calculées à partir de l’incisive sont plus précises que celles calculées à partir de la canine ou de la prémolaire; b) les estimations d’âge calculées à partir des comptages maximaux sont plus précises que celles issues des comptes moyens; c) les estimations d’âge obtenues à partir des incisives mandibulaires sont plus précises que celles issues des incisives supérieures. Enfin, on observe une variabilité conséquente du nombre de lignes d’incrément sur la même dent. À l’échelle de l’individu, l’estimation de l’âge au décès entre deux dents peut différer de 26 ans, ce qui induit un biais dans l’estimation de l’âge à partir de ce paramètre.AbstractThe reliability of adult age-at-death estimates based on counting the incremental lines in dental cementum is uncertain because their accuracy and precision vary from one study to another. Moreover, no previous study has addressed intra-individual variability in counts of incremental lines in cementum. We quantified this variability from a sample of 51 clinically extracted teeth of 15 individuals. Incremental lines were counted on five cross sections from the median third of each tooth root. Two age estimates were calculated per tooth, taking into account (1) the maximum number of lines counted and (2) the average value of counts. Our results show that a) age estimates based on the incisor are more accurate than those based on the canine or premolar; b) age estimates based on maximum counts are more accurate than those based on average counts; c) age estimates based on mandibular incisors are more accurate than those based on maxillary incisors. Substantial variability was observed in the number of increment lines on the same tooth. For an individual, the estimated age at death between two teeth can differ by 26 years, which produces a bias in age estimations from this parameter.