Antiquity and geographic distribution of cranial modification among the prehistoric groups of Fuego-Patagonia, Chile.

OBJECTIVES: Nineteenth and twentieth century documents testify that four ethnic groups, generally classified as terrestrial hunters or canoe nomads, inhabited Fuego-Patagonia. Archaeologically, however, their presence and temporal depth remains unknown. This study analyzes the antiquity and geographic distribution of cranial modification, a highly visible symbol of social identity, in Fuego-Patagonia, Chile, to assess whether it expressed ethnic affiliation. MATERIALS AND METHODS: A total of 60 adult skulls from Southern Patagonia (n = 32; 53.3%) and Tierra del Fuego (n = 28; 46.7%) were examined for age-at-death, sex and cranial modification with standard methods. Individuals were further categorized as terrestrial (n = 26; 43.3%), marine (n = 21; 35%) or indetermined hunter-gatherers (n = 13; 21.7%) based on the archaeological site's characteristics, geographic location, and isotopic information. RESULTS: Thirty percent (n = 18) of the skulls in this study were modified, and most of the modified skulls (n = 15) presented a tabular-erect shape. No statistically significant differences were identified between Fuegians and Patagonians, males or females, or between the different types of adaptation and geographic locations. DISCUSSION: Thus, this Late Holocene, widely distributed practice, was not a reflection of ethnicity, but a material expression of information circulation and the complex social relations that these small-size groups had with one another. These results suggest that the emergence of modern ethnic identities in the region is a historic process that resulted from the interaction of local groups with European and Criollos.

Spatial regression techniques for inter-population data: studying the relationships between morphological and environmental variation.

Understanding the importance of environmental dimensions behind the morphological variation among populations has long been a central goal of evolutionary biology. The main objective of this study was to review the spatial regression techniques employed to test the association between morphological and environmental variables. In addition, we show empirically how spatial regression techniques can be used to test the association of cranial form variation among worldwide human populations with a set of ecological variables, taking into account the spatial autocorrelation in data. We suggest that spatial autocorrelation must be studied to explore the spatial structure underlying morphological variation and incorporated in regression models to provide more accurate statistical estimates of the relationships between morphological and ecological variables. Finally, we discuss the statistical properties of these techniques and the underlying reasons for using the spatial approach in population studies.

Craneoplastia cnn costilla, procedimiento ideal: reporte de un caso / Split rib cranioplasty ideal procedure for Bolivia and the world: case report

aso de craneoplastia con costilla en un paciente con un síndrome de colgajo hundido, hacemos énfasis en la posibilidad de utilizar un injerto autológo, en este caso costilla en lugar de aloinjertos, siempre que sea posible. Las causas del problema fueron un defecto de la bóveda craneal secundaria a una craneotomía por edema cerebral pos-traumático y la colocación de una derivación ventrículo peritoneal. Los resultados obtenidos tanto desde el punto de vista neurofuncional como estético fueron excelentes.

A case of the syndrome of sinking skin flap and his treatment by performing slip rip autograph cranioplasty, the reasons for cranial reconstruction were calvaría defect from previous craniotomy a VP shunt. We emphasize on the convenience of the use of rib auto graft cranioplasty. Results were excellent.

Tipo de crecimiento y patrón esqueletal craneofacial en niños y niñas de 7 a 11 años que asistieron a la Facultad de Odontología en el período agosto 2006 - agosto 2007 / Type of growth and craniofacial skeletal pattern in boys and girls aged 7 to 11 who attended the School of Dentistry in the period August 2006 - August 2007

El crecimiento craneofacial y patrón Esqueletal es importante porque todos los mecanismos de crecimiento, son procesos morfogenéticos encaminados hacia un equilibrio funcional del complejo maxilofacial. Por lo tanto, el objetivo es Describir y comparar radiográficamente el crecimiento y patrón Esqueletal craneofacial más frecuentes por género, con una muestra de 165 radiografías del Centro de Imágenes la Facultad de Odontología de la Universidad de El Salvador, efectuadas en Agosto 2006-2007. Esta investigación es de tipo Descriptiva. Las variables fueron género, patrón Esqueletal y tipo de crecimiento. Los datos se procesaron en el programa Stadistical Product for Service Solutions 16.0 (SPSS). El crecimiento craneofacial en el género femenino es 44.2% neutro y 14.5% vertical; el género masculino presento crecimiento neutro un 32.7%, 7.9% vertical y 0.6% horizontal. Siendo el crecimiento neutro más frecuente para ambos géneros. El patrón Esqueletal presento en el género femenino 13.3% clase I, 45.5% clase II y el género masculino presento 6.7% clase I; 31.1% clase II; y 2.4% clase III. Siendo el patrón clase II más frecuente. Se obtuvo un alto número de pacientes clase II considerándose este uno de los más complejos, combinado con un crecimiento vertical, podría dificultar el manejo del paciente. Importante recordar a estudiantes y odontólogos a reorientar el crecimiento, modificando hábitos o funciones incorrectas con el uso de aparatología; utilizadas en forma precoz durante la maduración del niño; además mediante una detección temprana con hallazgos clínicos, patrón Esqueletal y crecimiento craneofacial; el manejo podría verse simplificado y obtener mejores resultados.

Craniofacial growth and skeletal pattern is important because all growth mechanisms are morphogenetic processes directed towards a functional balance of the maxillofacial complex. Therefore, the objective is to describe and radiographically compare the most frequent growth and craniofacial skeletal pattern by gender, with a sample of 165 radiographs from the Imaging Center of the Faculty of Dentistry of the University of El Salvador, carried out in August 2006-2007. This research is descriptive. The variables were gender, skeletal pattern and type of growth. The data were processed in the Statistical Product for Service Solutions 16.0 (SPSS) program. The craniofacial growth in the female gender is 44.2% neutral and 14.5% vertical; the male gender presented neutral growth of 32.7%, 7.9% vertical and 0.6% horizontal. Being the most frequent neutral growth for both genders. The skeletal pattern presented in the female gender 13.3% class I, 45.5% class II and the male gender presented 6.7% class I; 31.1% class II; and 2.4% class III. Being the most frequent class II pattern. A high number of class II patients was obtained, considering this one of the most complex, combined with vertical growth, it could make patient management difficult. It is important to remind students and dentists to reorient growth, modifying incorrect habits or functions with the use of appliances; used early during the maturation of the child; also by early detection with clinical findings, skeletal pattern and craniofacial growth; the handling could be simplified and get better results.

East-West cranial differentiation in pre-Columbian populations from Central and North America.

In a recent study we found that crania from South Amerindian populations on each side of the Andes differ significantly in terms of craniofacial shape. Western populations formed one morphological group, distributed continuously over 14,000km from the Fuegian archipelago (southern Chile) to the Zulia region (northwestern Venezuela). Easterners formed another group, distributed from the Atlantic Coast up to the eastern foothills of the Andes. This differentiation is further supported by several genetic studies, and indirectly by ecological and archaeological studies. Some authors suggest that this dual biological pattern is consistent with differential rates of gene flow and genetic drift operating on both sides of the Cordillera due to historical reasons. Here we show that such East-West patterning is also observable in North America. We suggest that the "ecological zones model" proposed by Dixon, explaining the spread of the early Americans along a Pacific dispersal corridor, combined with the evolution of different population dynamics in both regions, is the most parsimonious mechanism to explain the observed patterns of within- and between-group craniofacial variability.

Detection of a population replacement at the Classic-Postclassic transition in Mexico.

The Mexica Empire reached an outstanding social, economic and politic organization among Mesoamerican civilizations. Even though archaeology and history provide substantial information about their past, their biological origin and the demographic consequences of their settlement in the Central Valley of Mexico remain unsolved. Two main hypotheses compete to explain the Mexica origin: a social reorganization of the groups already present in the Central Valley after the fall of the Classic centres or a population replacement of the Mesoamerican groups by migrants from the north and the consequent setting up of the Mexica society. Here, we show that the main changes in the facial phenotype occur during the Classic-Postclassic transition, rather than in the rise of the Mexica. Furthermore, Mexica facial morphology seems to be already present in the early phases of the Postclassic epoch and is not related to the northern facial pattern. A combination of geometric morphometrics with Relethford-Blangero analyses of within- versus among-group variation indicates that Postclassic groups are more variable than expected. This result suggests that intense gene exchange was likely after the fall of the Classic and maybe responsible for the Postclassic facial phenotype. The source population for the Postclassic groups could be located somewhere in western Mesoamerica, since North Mexico and Central Mesoamerican Preclassic and Classic groups are clearly divergent from the Postclassic ones. Similarity among Preclassic and Classic groups and those from Aridoamerica could be reflecting the ancestral phenotypic pattern characteristic of the groups that first settled Mesoamerica.

Phenotypic evolution of human craniofacial morphology after admixture: a geometric morphometrics approach.

An evolutionary, diachronic approach to the phenotypic craniofacial pattern arisen in a human population after high levels of admixture and gene flow was achieved by means of geometric morphometrics. Admixture has long been studied after molecular data. Nevertheless, few efforts have been made to explain the morphological outcome in human craniofacial samples. The Spanish-Amerindian contact can be considered a good scenario for such an analysis. Here we present a comparative analysis of craniofacial shape changes observed between two putative ancestor groups, Spanish and precontact Aztecs, and two diachronic admixed groups, corresponding to early and late colonial periods from the Mexico's Central Valley. Quantitative shape comparisons of Amerindian, Spanish, and admixed groups were used to test the expectations of quantitative genetics for admixture events. In its simplest form, this prediction states that an admixed group will present phenotypic values falling between those of both parental groups. Results show that, in general terms, although the human skull is a complex, integrated structure, the craniofacial morphology observed fits the theoretical expectations of quantitative genetics. Thus, it is predictive of population structure and history. In fact, results obtained after the craniofacial analysis are in accordance with previous molecular and historical interpretations, providing evidence that admixture is a main microevolutionary agent influencing modern Mexican gene pool. However, expectations are not straightforward when moderate shape changes are considered. Deviations detected at localized structures, such as the upper and lower face, highlight the evolution of a craniofacial pattern exclusively inherent to the admixed groups, indicating that quantitative characters might respond to admixture in a complicated, nondirectional way.

Functional-cranial approach to the influence of economic strategy on skull morphology.

Environmental factors are assumed to play an important role in the shaping of craniofacial morphology. Here we propose a statistical approach which can be of utility in estimating the magnitude and localization of a particular nongenetic factor upon the specific functional components of the skull. Our analysis is a combination of previous attempts of apportionment of variance and the application of craniofunctional theory. The effect of subsistence strategy on craniofacial functional components was studied on 18 populations of hunter-gatherers and farmers from South America. Results demonstrate that the environmental factors studied likely influenced the masticatory component's size and shape. Even when this effect is not large enough to clearly differentiate among subsistence strategies (since whole craniofacial variation among populations remains greater), the method used here provides interesting clues to localize plastic or adaptive responses to external stimuli.

Late Pleistocene/Holocene craniofacial morphology in Mesoamerican Paleoindians: implications for the peopling of the New World.

Several studies on craniofacial morphology showed that most Paleoindians, who were the first settlers of the New World, clearly differ from modern Amerindians and East Asians, their supposed descendants and sister group, respectively. Here we present new evidence supporting this view from the Late Pleistocene/Early Holocene horizon from Mexico, as well as from the most complete set of dated Paleoindian remains. We analyzed the phenotypic resemblance of early Mexicans with other South Paleoamerican and modern human series. Two independent approaches to the data were used. In the first case, individual specimens were tested for morphological similarity with a set of modern reference samples. In the second analysis, Mexican specimens were treated as a sample in order to compute minimum genetic distances. Results from both approaches tend to associate early Mexican skulls with Paleoindians from Brazil, an Archaic sample from Colombia, and several circum-Pacific populations. These results give support to a model in which morphologically generalized groups of non-Northeast Asian descent (the so-called Paleoamericans) entered the continent first, and then dispersed from North to South America through Central America. The large geographic dispersal of Paleoamericans, and their presence in Mexico in the Early Holocene, raise new issues about the continent's settlement scenario.

South Amerindian craniofacial morphology: diversity and implications for Amerindian evolution.

The most compelling models concerning the peopling of the Americas consider that modern Amerindians share a common biological pattern, showing affinities with populations of the Asian Northeast. The aim of the present study was to assess the degree of variation of craniofacial morphology of South American Amerindians in a worldwide context. Forty-three linear variables were analyzed on crania derived from American, Asian, Australo-Melanesian, European, South-Saharan African, and Polynesian regions. South America was represented by seven Amerindian samples. In order to understand morphologic diversity among Amerindians of South America, variation was estimated using regions and local populations as units of analysis. Variances and F(ST) values were calculated for each unit, respectively. Both analyses indicated that morphologic variation in Southern Amerindians is extremely high: an F(ST) of 0.01531 was obtained for Southern Amerindians, and values from 0.0371-0.1205 for other world regions. Some aspects linked to the time and mode of the peopling of the Americas and various microevolutionary processes undergone by Amerindians are discussed. Some of the alternatives proposed to explain this high variation include: a greater antiquity of the peopling than what is mostly accepted, a peopling by several highly differentiated waves, an important effect of genetic drift, and gene flow with Paleoamericans. A combination of some of these alternatives explains at least some of the variation.

Desgastes oclusales en dientes ancestrales / Oclusales abrasions in ancients teeth

Se investigó los patrones de abrasiones oclusales en dientes de diez y seis indios Changos que vivieron entre los siglos VII y XII D.C en la costa de norte chileno, cuyos cráneos se rescataron desde sitios arqueológicos en Mejillones y Antofagasta. Se utilizó la escala Molnar para determinar el grado de abrasión oclusal en dientes permanentes Los resultados sugieren que en la alimentación de estos habitantes existió una alta proporción de partículas abrasivas (arena), no registrándose evidencias que estas abrasiones se deban al uso de la dentadura como herramienta. También debió haber ocurrir un cambio en el sistema neuromuscular del sistema estomatognático, generándose una mordida bis a bis, transformado la curva de Spee hasta llegar a desaparecer. En la mayoría de las dentaduras no se observan caries y muestran sus terceros molares erupcionados.

Patterns of occlusional abrasions were studied in teeth from skulls of 16 indigenous inhabitants ("Changos") from northern Chile living in the VIII and the XII centuries AD. The skulls were obtained from archeological sites in Mejillones and Antofagasta (23º5'S). The Molnar scale was used to determine the degree of occlusional abrasion of permanent teeth. The results suggested a high proportion of abrasional material (sand) occurred in the diets of these people, and no evidence was found of abrasion due to using the teeth as tools. Also, there must have been a change in the stomatognathic neuromuscular system, producing a "bis to bis"bite, thus transforming the Spee curve until its nearly complete disappearance. No caries were observed in a majority of the dentitions, and most had the third molar erupted.

Desenvolvimento infantil e desnutrição: crescimento e modo de brincar de crianças de 4 a 18 meses internadas no IMIP / Infantile development and malnutrition: growth and way of playing of children of 4 to 18 months interned in IMIP

OBJETIVO: Comparar o comportamento lúdico entre crianças eutróficas e desnutridas, verificando sua associação com variáveis sócio-demográficas e crescimento craniano diferencial.MÉTODO: Crianças de quatro a 18 meses, internadas no Instituto Materno Infantil de Pernambuco, sendo 47 eutróficas e 45 desnutridas, foram classificadas segundo indicador peso/idade (NCHS), considerando-se desnutridas aquelas com score Z menor que û2 . Foram registrados a sua circunferência craniana e o comprimento. Dados sobre idade , escolaridade materna, procedência, renda familiar e sobre o brincar da criança no lar foram obtidos por questionário aos pais. O crescimento diferencial do crânio ( circunferência craniana/comprimento ) foi determinado. O brincar foi avaliado por scores de 1 a 10. RESULTADOS: Mais baixo desempenho lúdico do grupo desnutrido mostrou-se associado a idade materna superior a 25 anos (p<0,001), a menor escolaridade materna (p=0,003), a maior aglomeração familiar (p,0,001) e menor renda (p=0,005). Redução do crescimento craniano (p<0,001) e do desempenho lúdico (p<0,001) foram observados nos desnutridos do sexo masculino, mas não nos do feminino.CONCLUSÕES: A desnutrição, isoladamente ou associada a condições sócio-demográficas precárias, prejudica o desempenho, no comportamento lúdico. Nas crianças desnutridas, alterações no ritmo do crescimento craniano podem estar relacionadas à diferença no desempenho lúdico entre os gêneros.

The settlement of Patagonia: a matrix correlation study.

Matrix correlation represents an innovative methodology to evaluate the explanatory power of several hypotheses by measuring their correspondence with observed morphological variation. In this paper, we view the origins of Patagonians from a matrix correlation approach. Personal and published data on nonmetric cranial traits were used to estimate a biological distance matrix involving five major groups from Patagonia and two from the northwest and northeast regions of Argentina. To evaluate correspondence with other important factors, we used a geographic distance matrix and four design matrices, representing several patterns of settlement and differentiation. Biological distance was found to be strongly associated with spatial separation; the correlation between geography and nonmetric cranial distances was highly significant. When geographic distance is held constant, correlation between a model representing high levels of heterogeneity between the samples and morphological (nonmetric) variation becomes highly significant.

Estudio anátomo-radiológico craneocervical en 60 estudiantes de la Universidad de la Frontera / Anatomo radiological study of cranio cervical region in 60 students at Universidad de la Frontera

To evaluate the cranio cervical region from a radiological point of view in healthy young adults, a lateral head and neck radiological study, using the technique described by Rocabado, was done to 60 chilean young adults, aged 19 to 24 years old. The cervical curvature was altered in 70 percent of subjects (kyphosis in 35 percent, straightening in 33 percent and lordosis in 1.7 percent). Sixty eight percent had alteration of the hyoid triangle (in the plane in 31,7 percent and inverted in 37 percent). The distance between C0 and C1 was altered in 48 percent (less than 4 mm in 15 percent and more than 9 mm in 33 percents). An altered posteroinferior angle was observed in 40 percent (less than 96º in 30 percent and over 106º in 10 percent). A high percentage of alterations of the craniocervical region was detected in healthy adults

Morbilidad oral en una comunidad de cráneos prehispánicos Tunja, Boyacá, Colombia / Oral morbidity in a prehispanic skulls community Tunja, Boyacá, Colombia

En una comunidad de 39 cráneos prehispánicos encontrados en Tunja, Boyacá, Colombia, se examinaron sus estructuras dentales. Se encontró que presentan un 88.0 por ciento de los dientes presentes en condición de sanos, que el índice COP es de 4.3 y un 63.6 por ciento de la población de cráneos con antecedentes de caries dentales. De las otras patologías en dientes permanentes el 74.3 por ciento de la población de cráneos está afectada por atrición (desgaste oclusal) y el 94.0 por ciento de los dientes presentes manifiestan esa condición. De las anomalías dentomaxilofaciales la de mayor prevalencia son las diastemas, apiñamiento y mordida cruzada posterior