Scuola di Specializzazione in Psioterapia della Gestalt

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 Demirjian's method used as a reference today, and permit age estimation till 20 years of age.

Accurate age determination is fundamental in both forensic medicine and anthropology. Many methods that relate dental characteristics to adult age have been proposed, but there is still no simple and reliable method that does not damage the study material. The aim of this work was to propose a relevant and practical technique for determining age in adults that could be used in both living and deceased individuals. The sample was composed of 210 CT scans from individuals aged from 15 to 85 years old, with four healthy canines present in the mouth. The 840 canines were modelled using Mimics® 10.01 software. The pulp volume/total volume ratio ×100 was determined for each tooth. Seven mathematical models, corresponding to all possible real situations, were determined by the weighted least squares method and ranked in order of relative performance. The adequacy of the seven models to the data was very high with the regressions proposed (0.915 < R (2) adjusted < 0.964). Ranked in order of performance, the maxillary model was the most powerful of the seven models for age determination, followed by the 4 canines model, the 13 model and the 23 model.

HLA DR4 antigens have been considered as a risk factor in periodontal disease. The aim of this "case control" study was to verify and to provide fuller clarification of such data. "Cases" or patients had to be aged between 20 and 48 years. They presented at least 5 sites spread over several teeth with an attachment loss equal or greater than 6 mm, and 10 sites spread over several teeth with periodontal pockets equal to or greater than 5 mm. Verification with a WHO probe showed an individual CPITN score of 4. Moreover, subjects whose average CPITN score for the 6 sextants was less than 3 were excluded from the study. Among these "severe periodontitis" patients, a subgroup was distinguished composed of subjects aged 20-35 years who presented, in accordance with the cases by Katz and co-workers, 5 or more teeth showing pocket depths of 6 mm or more. The dental chartings of these subjects showed an attachment loss of more than 3 mm on certain teeth over an inter-exam period of 1-3 years. They all displayed obvious loss of bony support in the affected sites. This constituted the "rapidly progressive periodontitis" subgroup. The "controls" were all over 20 years of age, and it was clinically verified that they were free of periodontal disease. There were 48 "cases" and 55 "controls". HLA typing of patients and controls was performed using "sequence oligoprobe hybridization after polymerase chain reaction" in accordance with the 11th International Workshop. This method allowed the detection of DR4 alleles as well as DR4 subtypes. The ethno-geographic origin of the subjects, considered as a confounding variable, was neutralized by stratified analysis. Subtypes 0401, 0404, 0405 and 0408 tended to be more frequent (p=0.08) in the cases (Severe Periodontitis). Focusing on analysis of "rapidly progressive periodontitis" in subjects aged 20-35 years, a very significant Mantel-Haenszel chi2 was obtained (p=0.0058) which led to a Mantel-Haenszel standardized odds ratio (OR) equal to 17. The 95% confidence interval was 1.03<0.R.<180.10. In conclusion, this supports previous reports and gives further clarification: in particular subtypes 0401, 0404, 0405 and 0408 can be considered as a risk factor for "rapidly progressive periodontitis". It should be noted that these determinants have been implicated in rheumatoid arthritis.

The aim of this study was to establish a prediction formula to allow for the determination of sex among the southeastern French population using dental measurements. The sample consisted of 105 individuals (57 males and 48 females, aged between 18 and 25 years). Dental measurements were calculated using Euclidean distances, in three-dimensional space, from point coordinates obtained by a Microscribe. A multiple logistic regression analysis was performed to establish the prediction formula. Among 12 selected dental distances, a stepwise logistic regression analysis highlighted the two most significant discriminate predictors of sex: one located at the mandible and the other at the maxilla. A cutpoint was proposed to prediction of true sex. The prediction formula was then tested on a validation sample (20 males and 34 females, aged between 18 and 62 years and with a history of orthodontics or restorative care) to evaluate the accuracy of the method.

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.

We carried out a biometric study of the mandible during the last two trimesters of fetal life using three-dimensional tomodensitometric images. We first validated the method of fetal mandible measurement from three-dimensional reconstructions, and then compared these measurements with direct measurements on dissected mandibles. Thanks to the biometric technique on three-dimensional images, dissection of mandibles is no longer necessary, allowing the material to be conserved for later studies. Tomodensitometric images of the whole fetal skull can be obtained in 10 minutes, a much shorter time than that required for dissection of the fetal mandible. Another major advantage is the possibility of computerized image storage, which allows subsequent studies on the same material, its observation and manipulation as well as exchange of findings with the research community, with no risk of damage to the original material.

Two probabilist methods of age prediction in children are proposed: they are both based on the radiological presence of erupted teeth or germs. Using an apprenticeship sample of known age and sex, we established several discriminant models (+/- 13, +/- 16, +/- 18 years old). We also evaluated a Bayesian model with the following age groups: < 13, [13-16[, [16-18[, > or = 18 years old, or [X and Y] years old. When applied on a known test sample, Fisher's linear functions presented a success rate greater than 90%, above 13 years threshold, and below 16 and 18 years thresholds, and Bayesian approach, greater than 85%. Therefore, these methods provide an interesting alternative for children age determination that can be applied in biological and forensic anthropology, too.

La méthode d’estimation de l’âge au décès adulte par comptage des anneaux du cément dentaire n’est actuellement pas consensuelle car fiabilité et précision diffèrent d’une étude à l’autre. L’observation du tissu cémentaire au microscope optique montre que le nombre de lignes d’incrément et la largeur de la bande cémentaire varient selon la face dentaire et la dent considérées. Pourtant, aucune étude ne s’est consacrée à la variabilité intra-individuelle du cément jusqu’à présent. Avec un échantillon de 51 dents monoradiculées contemporaines d’âge connu extraites sur 15 individus, nous avons manuellement compté les anneaux sur cinq sections transversales issues du tiers médian radiculaire de chaque dent. Deux estimations de l’âge par dent ont été calculées : 1) avec le nombre maximal de lignes comptées et 2) avec la valeur moyenne des comptages, auxquels est ajouté l’âge d’éruption moyen. Nos résultats révèlent une variabilité de l’estimation de l’âge, parfois très élevée : jusqu’à 3...

La 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 estimatio...

The study of intra-individual variability of acellular cementum apposition is a major issue in the estimation of age-at-death usingcementochronology. Since the literature is scarce on the subject we extracted 51 modern teeth from 15 of known-age patients. We manually counted the acellular cementum increments on five cross sections from the middle third root of each tooth. Age estimation was then calculated by summing the number of lines to the average age of dental eruption. Our results showed some variability between counts within tooth, especially on premolars. The intra-individual variability of cementum deposition has been highlighted by comparing age estimates obtained for each tooth of one individual which is not surprising considering problems already described in the literature on this issue. Once premolars were excluded, the variation between teeth of an individual dropped to 0 to 5 years in 73% of cases. In conclusion, the intra-individual and intra-dental variability of c...