Estimación de la edad de individuos infantiles en antropología forense. Resultados para la edad dental en una muestra de origen mediterráneo

Laburpena

ABSTRACT Forensic Anthropology has evolved and expanded considerably over the past half century. It is now a key discipline of forensic sciences, responsible for important tasks in numerous medical-legal contexts, such as the identification of missing persons, interpretation of skeletal lesions in relation to the manner and cause of death, and support in cases of mass disasters, such as earthquakes, tsunamis, floods, and terrorist attacks. It is also used for the study of living people in reference to immigration issues, paternity, and juvenile law, among others. Research in forensic anthropology is currently focused on responding to all of these societal needs, offering methods and techniques with a high degree of certainty and discriminatory power, essential if results are to be useful for judicial purposes. However, it is highly challenging to yield results with these qualities in the study of children, because of the absence of adequate reference samples for this age group, which represents a major limitation worldwide. The present investigation was developed after the Laboratory of Anthropology of the University of Granada acquired the largest ontological collection of identified infants and young children in the world, aged from 5 months of gestation to 8 years. The creation of this collection is the result of collaborative work between the Laboratory and the San José Cemetery of Granada. The main objective of this thesis was to initiate the study of this collection from the perspective of Forensic Anthropology in order to serve as a guide for its future complete analysis. This general objective was focused on preparing the sample for its study and providing preliminary results to support the creation of a novel forensic methodology adapted to the Mediterranean population. This thesis represents an early stage in a well-defined and very extensive research line. The collection offers a wide range of study possibilities. Initial research on key topics has resulted in the publication of three articles in leading scientific journals in this field, all indexed and in the first quartile of their group. Their main objectives and results are summarized below: Alemán I, Irurita J, Valencia AR, Martinez A, Lopez-Lazaro S, Viciano J, Botella MC (2012) Brief communication: The Granada osteological collection of identified infants and young children. Am J Phys Anthropol 149: 606¿610. Impact factor 2.481. Position 7 of 83 (Q1). The objective of this study is to present the characteristics of a collection of identified infants and young children housed in the Laboratory of Anthropology of the University of Granada, Spain. The sample, which is still being enlarged, is currently composed of 230 complete skeletons aged from 5 months of gestation to 8 years, with a majority below 1 year. It mainly dates from the mid-20th century. The state of preservation is very good, and antemortem information is available from burial and death certificates, among other documents. Our sample makes an important contribution to the relatively few collections available in the world for investigating the osteological development of the skeletons of infants and young children from a physical anthropological perspective. Irurita J, Alemán I, Viciano J, De Luca S, Botella MC (2013) Evaluation of the maximum length of deciduous teeth for estimation of the age of infants and young children: proposal of new regression formulas. Int J Legal Med. DOI 10.1007/s00414-013-0903-y. Impact factor 2.686. Position 3 of 16 (Q1). The methodology used to identify individuals in forensic anthropology requires a minimum degree of precision and accuracy and should be based on identified and representative samples. Achievement of these objectives in infant skeletons is hampered by the scarcity of appropriate samples. The dental age estimation methods of Liversidge et al. (Am J Phys Anthropol 90: 307¿313, 1993) and Deutsch et al. (Growth 49: 207¿17, 1985) were applied to the Granada osteological collection of identified infants (Granada, Spain) in order to evaluate its applicability in a Mediterranean population. Significant differences were found between the estimated and real ages in both cases. Based on the measurements obtained in 140 fetuses and infants, new regression formulas were developed to estimate age from the metric study on deciduous teeth. Independent functions are provided for each deciduous maxillary and mandibular tooth in each sex, along with the margin of error (95 % confidence interval). These formulas appear to offer one of the best methods available for estimating the age of Mediterranean infants in forensic anthropology settings. Irurita J, Alemán I, López-Lázaro S, Viciano J, Botella MC (2014) Chronology of the development of deciduous dentition in Mediterranean population. Am J Phys Anthropol . In press. Impact factor 2.481. Position 7 of 83 (Q1). The objective of this study of the maturation of deciduous dentition was to offer a novel age-estimation method for Mediterranean populations, using the osteological collection of fetuses, infants, and young children in the Anthropology Laboratory of Granada University (Spain) as study material. After excluding premature newborns and infants with disease, the final study sample comprised 1,303 deciduous teeth suitable for analysis from 138 individuals (80 male, 58 female) aged between 24 weeks in utero and 6 years. Eleven mineralization stages were defined for the dental maturation analysis, and the alveolar emergence was also studied. The criteria published by Demirjian et al. in 1973, by Moorrees et al. in 1963, and by Liversidge et al. in 2004 were combined and modified for this purpose. The reproducibility of the proposed method is supported by the low intra- and inter-observer error in the identification of these development stages. The results provide information on the mean age of attainment of each of 11 mineralization stages and on the average age for each stage in each deciduous tooth type, considering each sex separately and both sexes combined. A general conclusion to be drawn from these three publications is that the Granada osteological collection of identified infants and young children offers enormous research potential for developing a forensic anthropology methodology in children that meets the stringent requirements of this discipline. Further comprehensive studies are warranted to test and validate the proposals developed in these articles.