Características craneofaciales de pacientes obesos en Chile. Estudio Preliminar / Craniofacial characteristics of obese patients in Chile. Preliminary study

Resumen Introducción: La obesidad es un problema a nivel global que enfrenta el siglo XXI y Chile no se escapa de esta realidad. Así como existen características mórbidas de pacientes con obesidad, también existen características craneofaciales similares en estos pacientes. El estado nutricional es un factor que influencia el desarrollo de una persona en general, lo que tiene implicancias en el tratamiento ortodóncico, ortopédico y quirúrgico de las alteraciones maxilo - mandibulares de los pacientes. Objetivo: Investigar si la morfología craneofacial difiere entre los adolescentes obesos y los de peso normal. Métodos: Estudio retrospectivo, se basó en la comparación de medidas craneofaciales obtenidas del análisis cefalométrico, utilizando teleradiografías laterales, de dos grupos: grupo estudio (IMC mayor a 30, obeso) y grupo control (IMC normal). Resultados: Se observaron dimensiones maxilares y mandibulares mayores en el grupo estudio comparado con los pacientes del grupo control. Las medidas para la dimensión maxilar tuvieron diferencia significativamente estadística. Conclusiones: El aumento de peso es un factor importante que puede afectar los patrones de crecimiento craneofacial y debe ser tomado en consideración durante la planificación del tratamiento ortodoncico en pacientes adolescentes.

Abstract Introduction: Obesity is a global problem in the the 21st century and Chile does not escape this reality. Just as there are morbid characteristics of patients with obesity, there also share similar craniofacial characteristics. Nutritional status is a factor that influences the a person´s general development , which has implications in the orthodontic, orthopedic and surgical treatments of maxillo-mandibular alterations. Objective: Investigate whether craniofacial morphology differs between obese and average-weight adolescents. Methods: A retrospective study based on the comparison of craniofacial measures obtained from the cephalometric analysis, using lateral cephalograms, from two groups: study group (BMI over 30, obese) and control group (normal BMI). Greater maxillary and mandibular dimensions were observed in the study group compared to the patients in the control group. The measurements for de maxillary dimension had a statistically significant difference. Conclusions: Weight gain is an important factor that can affect craniofacial growth patterns and should be taken into consideration during the planning of orthodontic treatment in adolescent patients.

Effects of malocclusions on facial attractiveness and their correlations with the divine proportion.

PURPOSE: The aim of this study was to evaluate the effects of malocclusions on facial attractiveness and to determine if it was correlated with the divine proportion. METHODS: Standard frontal facial photos were taken from 335 subjects in natural head position. Facial attractiveness of the subjects was evaluated by 10 dental students using a 10-point visual analog scale (VAS). All of the evaluations were arranged in order, and 30 attractive subjects with the highest score and 30 nonattractive subjects having the lowest score were chosen. On the frontal photos of these subjects, 13 landmarks were determined and 12 ratios were measured. Two way ANOVA was used to determine the effects of malocclusions on facial attractiveness, Student's t test was used to compare the facial proportions of the attractive and nonattractive subjects, and one sample t test was used to define the relationships between the divine proportion and facial ratios. RESULTS: No statistically significant difference was found between malocclusion groups in terms of facial attractiveness. Of the 12 facial ratios, significant differences were found between attractive and nonattractive subjects regarding trichion-menton/nasion-menton, subnasale-menton/stomion-menton, nasion-subnasale/stomion-menton, nasion-subnasale/nasal width, and trichion-menton/right-left frontotemporale ratios. All of the ratios except nasion-subnasale/stomion-menton in the attractive group and subnasale-menton/stomion-menton and nasion-menton/nasion-trichion in the nonattractive group were found to be different from the divine proportion. CONCLUSIONS: Sagittal skeletal malocclusions evaluated by ANB angle are not effective on facial attractiveness. Facial ratios used in this study have little effect on attractiveness, and are different from the divine proportion.

The Color Wheel: A Heuristic Aid in Classification of a Skeletal Pattern.

Reading a complete print-out of cephalometric analysis expressed numerically consumes a fair amount of our time. The present paper addresses this issue by describing the "color wheel," a computerized procedure that attributes to the patient a single color representing type and severity of a skeletalproblem.

Facial soft tissue thickness differences among three skeletal classes in Japanese population.

Facial reconstruction is used in forensic anthropology to recreate the face from unknown human skeletal remains, and to elucidate the antemortem facial appearance. This requires accurate assessment of the skull (age, sex, ancestry, etc.) and thickness data. However, additional information is required to reconstruct the face as the information obtained from the skull is limited. Here, we aimed to examine the information from the skull that is required for accurate facial reconstruction. The human facial profile is classified into 3 shapes: straight, convex, and concave. These facial profiles facilitate recognition of individuals. The skeletal classes used in orthodontics are classified according to these 3 facial types. We have previously reported the differences between Japanese females. In the present study, we applied this classification for facial tissue measurement, compared the differences in tissue depth of each skeletal class for both sexes in the Japanese population, and elucidated the differences between the skeletal classes.

Clasificación de las alteraciones cefalogénicas desde una visión integradora craneomaxilofacial / Classification of cephalogenic alterations from a craneomaxilofacial integrative visión

Introducción: las clasificaciones sobre las alteraciones cefalogénicas presentan una gran dispersión debido a la multiplicidad de especialidades médicas que intervienen en la región de la cabeza. Objetivo: describir las clasificaciones más relevantes de las malformaciones craneofaciales y proponer una nueva clasificación. Métodos: se realizó un estudio mixto, hermenéutico y cuantitativo descriptivo, durante el cual se analizó la producción de clasificaciones sobre este tema en la Web of Sciences en el periodo comprendido desde 1992 hasta 2012. Luego de seleccionar 263 artículos que trataban este tema se estudiaron 22 de ellos en los que proponían clasificaciones o modificaciones al respecto. Se estudió la región anatómica, el tipo de clasificación, el tipo de malformación que describe y la revista de publicación. Resultados: hubo predominio del tipo de clasificación morfogénica en el 60 porciento, el tipo de malformación mayormente clasificada fue por defecto (fisuras e hipoplasias) en 72 por ciento y la revista con mayor representación de publicaciones sobre clasificaciones de alteraciones cefalogénicas fue TheJournal of Craniofacial Surgery donde se publicaron el 44 por ciento de ellas. Se propuso una clasificación integradora morfo-fisiopatológica y se analizó su validación interna y externa. Conclusiones: se demostró la ausencia de una clasificación que agrupara todas las malformaciones cefalogénicas, que incluyera a todas sus regiones anatómicas y tipos de malformaciones. La clasificación propuesta podría ser de utilidad para las especialidades médicas y estomatológicas afines a esta región anatómica(AU)

Introduction: classifications on cephalic alterations have great dispersion secondary to diversity of medical specialties involved in head region. Objective: to describe relevant classifications in craniofacial malformations and recommend a new classification. Method: was carried out a mixed study: hermeneutic and quantitative descriptive, to analyze the production of this kind of classifications on the Web of Sciences during the years 1992 to 2012. As result 263 papers was find on this topic and 22 papers were selected because provided classifications or modifications in this respect. This research analyzed the anatomical region, the classification type, the type of malformation and the magazine of publication. Results: there was a prevalence of the type of morphogenic classification in 60 percent, the mostly classified malformation type of by defect (fissures and hypoplasia) in 72 percent and the representative magazine of cephalic alterations classifications was the Journal of Craniofacial Surgery where 44 percent of them were published. An integrative morpho-physiopathologic classification was suggested and internal and external validation was analyzed. Conclusions: was demonstrated the absence of any classification that joined all the cephalic malformations of all the anatomical cephalic regions. The recommended classification would being of utility for medical and dentistry specialties related to this anatomical region(AU)

Clasificación de las alteraciones cefalogénicas desde una visión integradora craneomaxilofacial / Classification of cephalogenic alterations from a craneomaxilofacial integrative visión

Introducción: las clasificaciones sobre las alteraciones cefalogénicas presentan una gran dispersión debido a la multiplicidad de especialidades médicas que intervienen en la región de la cabeza. Objetivo: describir las clasificaciones más relevantes de las malformaciones craneofaciales y proponer una nueva clasificación. Métodos: se realizó un estudio mixto, hermenéutico y cuantitativo descriptivo, durante el cual se analizó la producción de clasificaciones sobre este tema en la Web of Sciences en el periodo comprendido desde 1992 hasta 2012. Luego de seleccionar 263 artículos que trataban este tema se estudiaron 22 de ellos en los que proponían clasificaciones o modificaciones al respecto. Se estudió la región anatómica, el tipo de clasificación, el tipo de malformación que describe y la revista de publicación. Resultados: hubo predominio del tipo de clasificación morfogénica en el 60 porciento, el tipo de malformación mayormente clasificada fue por defecto (fisuras e hipoplasias) en 72 por ciento y la revista con mayor representación de publicaciones sobre clasificaciones de alteraciones cefalogénicas fue TheJournal of Craniofacial Surgery donde se publicaron el 44 por ciento de ellas. Se propuso una clasificación integradora morfo-fisiopatológica y se analizó su validación interna y externa. Conclusiones: se demostró la ausencia de una clasificación que agrupara todas las malformaciones cefalogénicas, que incluyera a todas sus regiones anatómicas y tipos de malformaciones. La clasificación propuesta podría ser de utilidad para las especialidades médicas y estomatológicas afines a esta región anatómica(AU)

Introduction: classifications on cephalic alterations have great dispersion secondary to diversity of medical specialties involved in head region. Objective: to describe relevant classifications in craniofacial malformations and recommend a new classification. Method: was carried out a mixed study: hermeneutic and quantitative descriptive, to analyze the production of this kind of classifications on the Web of Sciences during the years 1992 to 2012. As result 263 papers was find on this topic and 22 papers were selected because provided classifications or modifications in this respect. This research analyzed the anatomical region, the classification type, the type of malformation and the magazine of publication. Results: there was a prevalence of the type of morphogenic classification in 60 percent, the mostly classified malformation type of by defect (fissures and hypoplasia) in 72 percent and the representative magazine of cephalic alterations classifications was the Journal of Craniofacial Surgery where 44 percent of them were published. An integrative morpho-physiopathologic classification was suggested and internal and external validation was analyzed. Conclusions: was demonstrated the absence of any classification that joined all the cephalic malformations of all the anatomical cephalic regions. The recommended classification would being of utility for medical and dentistry specialties related to this anatomical region(AU)

Evaluation of cephalic indices: a clue for racial and sex diversity / Evaluación del índice cefálico: una clave de la diversidad racial y de sexo

Cephalic index is an important parameter in evaluating racial and gender differences. A large body of evidence shows a clear racial variation in cephalic index. Therefore detailed knowledge of the population specific data on biometric features of the cranium is important in the study and comparison of the crania of populations from different racial backgrounds, assessing growth and development of an individual and in the diagnosis of any abnormalities of cranial size and shape. Despite its' significance, little is known concerning the cranial morphometry in Sri Lankans. Hence, the present study was undertaken to establish the cranial indices and head shapes in an adult Sri Lankan population. A total of 400 subjects with an age span of 20-23 years were included in the study. The cranial length, breadth and auricular head height of the subjects were recorded using a digital sliding caliper and Todd's head spanner. The horizontal, vertical and transverse cephalic indices were calculated using external dimensions of the skulls. There were significant gender differences in all principal cranial dimensions. The mean horizontal, vertical and transverse cephalic indices were 78.54, 78.68 and 100.52 respectively. The predominant cephalic phenotype of the study subjects were brachycephalic, hypsicephalic and acrocephalic. Among males dolicocephalics and among females brachycephalics dominated. The results of this study highlight the racial and gender differences in cranial morphometry and cephalic indices in an adult Sri Lankan population. The data will be of immense use in clinical, medico-legal, anthropological and archeological scenarios.

El índice cefálico es un parámetro importante para evaluar las diferencias raciales y sexuales. Una gran cantidad de evidencia muestra una clara variación racial en el índice cefálico. Por tanto, un conocimiento detallado de los datos específicos de una población sobre las características biométricas del cráneo, son importantes en el estudio y la comparación craneal de poblaciones de diferentes orígenes raciales, evaluación del crecimiento y desarrollo de un individuo, y el diagnóstico de cualquier anomalía del tamaño o forma del cráneo. A pesar de su importancia, poco se conoce sobre la morfometría craneal en Sri Lanka. El presente estudio se realizó para establecer los índices cefálicos y formas de la cabeza en una población adulta de Sri Lanka. Un total de 400 sujetos entre 20 y 23 años fueron incluidos en el estudio. La longitud de la cabeza, ancho y altura auricular fueron registradas con un caliper digital deslizante y un aparato de Todd. Los índices cefálicos horizontales, verticales y transversales fueron calculados utilizando las dimensiones externas de los cráneos. Hubo diferencias significativas de sexo en todas las dimensiones de la cabeza. La media horizontal, vertical y transversal de los índices cefálicos fueron 78,54; 78,68 y 100,52, respectivamente. Los fenotipos cefálicos predominantes fueron braquicéfalos, hipsicefálicos y acrocéfalos. Entre los hombres dominaron los dolicocefalos y entre mujeres los braquicéfalos. Los resultados de este estudio ponen de relieve la diversidad racial y las diferencias de sexo en la morfometría craneal e índice cefálico en una población adulta de Sri Lanka. La información será de utilidad inmensa en clínica, medicina legal, escenarios antropológicos y arqueológicos.

New model for surgical and nonsurgical therapy in adults with Class III malocclusion.

INTRODUCTION: Not all adult Class III malocclusion patients are candidates for surgical correction. In patient assessment and selection, major issues remain regarding diagnosis and treatment planning. The purpose of this investigation was to ascertain whether adding a transverse parameter to a discriminant analysis could improve the classification of adults with Class III malocclusion into 2 groups of patients: those who can effectively be treated by orthodontic therapy and those who require orthognathic surgery. METHODS: Cephalograms, plaster casts, and extraoral photos of 69 adults with Class III malocclusion were analyzed. A discriminant analysis was performed to identify the variables that best separate the 2 groups. RESULTS: Stepwise variable selection resulted in a new, highly significant (P <0.0001) model of 4 variables that provided the best discriminant function to distinguish between patients with and without indications for surgical correction. The resulting equation was the following: score = -10.988 + 0.243 * Wits + 0.055 * M/M ratio + 0.068 * NSAr - 0.589 * mand MLD. The percentage of patients correctly classified by this equation was 91.3%. The sensitivity was 0.92, and the specificity was 0.89. CONCLUSIONS: In the discriminant analysis, the mandibular midline deviation as a transverse component was included. The addition of the transverse variable led to an improved model concerning the predictive value in Class III malocclusion patients with surgical requirements.

Morphometric variation in the papionin muzzle and the biochronology of the South African Plio-Pleistocene karst cave deposits.

Papionin monkeys are widespread, relatively common members of Plio-Pleistocene faunal assemblages across Africa. For these reasons, papionin taxa have been used as biochronological indicators by which to infer the ages of the South African karst cave deposits. A recent morphometric study of South African fossil papionin muzzle shape concluded that its variation attests to a substantial and greater time depth for these sites than is generally estimated. This inference is significant, because accurate dating of the South African cave sites is critical to our knowledge of hominin evolution and mammalian biogeographic history. We here report the results of a comparative analysis of extant papionin monkeys by which variability of the South African fossil papionins may be assessed. The muzzles of 106 specimens representing six extant papionin genera were digitized and interlandmark distances were calculated. Results demonstrate that the overall amount of morphological variation present within the fossil assemblage fits comfortably within the range exhibited by the extant sample. We also performed a statistical experiment to assess the limitations imposed by small sample sizes, such as typically encountered in the fossil record. Results suggest that 15 specimens are sufficient to accurately represent the population mean for a given phenotype, but small sample sizes are insufficient to permit the accurate estimation of the population standard deviation, variance, and range. The suggestion that the muzzle morphology of fossil papionins attests to a considerable and previously unrecognized temporal depth of the South African karst cave sites is unwarranted.

Head morphology and degree of variation in lacerta bilineata: podarcis muralis and podarcis sicula / Morfología de la cabeza y el grado de variación en lacerta bilineata: podarcis muralis y podarcis sicula

The morphology of cephalic scales in Lacertids is organised in well defined geometrical structures. The variation of these elements is related to the underlying bone growth and morphogenesis, but it is also associated with the muscular system and the sutural dynamics. In this paper, the patterns of variation of the cephalic scales have been compared between three common Mediterranean species: Podarcis muralis, Podarcis sicula and Lacerta bilineata. The morphospace generated by the morphological relationships within the cephalic system in these three species is investigated in order to consider their degree of variation and their anatomical peculiarities. Generally, Lacerta is 64 percent larger than Podarcis, shows a relative reduction of the frontal scale, enlarged fronto-parietal structures, and stretched occipital area. L. bilineata shows the smaller degree of variation within the shape space, while P. muralis shows the highest values. The morphology of the two genera is definitely different mostly because of allometric variation. Non-allometric distinctions between the three species are subtle but detectable. The degree and pattern of variation are interpreted in terms of possible environmental pressures and of functional cranial dynamics associated with the fronto-parietal suture, respectively. In this sense, the structural relationships between bones and scales are of particular interest to further investigate ontogeny and phylogeny in reptiles.

La morfología de las escamas cefálicas en Lacértidos se organiza en estructuras geométricas bien definidas. La variación de estos elementos está relacionada con el crecimiento y la morfogénesis del hueso subyacente, pero está también es asociada con el sistema muscular y sutural dinámico. En este trabajo, son comparados los patrones de variación de las escamas cefálicas de tres especies mediterráneas comunes: Podarcis muralis, Podarcis sicula y Lacerta bilineata. El morfoespacio generado por las relaciones morfológicas con el sistema cefálico en estas tres especies se investigó con el fin de examinar su grado de variación y sus peculiaridades anatómicas. En general, Lacerta es 64 por ciento más grande que Podarcis, muestra una reducción relativa de la escama frontal, alargamiento de la estructura fronto-parietal, y estrechamiento del área occipital. L. bilineata muestra el menor grado de variación en la forma del espacio, mientras que P. muralis muestra los valores más altos. La morfología de los dos géneros es diferente principalmente debido a variaciones alométricas. Diferencias no alométricas entre las tres especies son sutiles pero detectables. El grado y el patrón de variación son interpretados en términos de las posibles presiones del medio ambiente y la dinámica funcional craneal asociada a la sutura fronto-parietal, respectivamente. En este sentido, las relaciones estructurales entre los huesos y las escamas son de particular interés para seguir investigando ontogenia y filogenia de los reptiles.

Lip vermilion profile patterns and corresponding dentoskeletal forms in female adults.

OBJECTIVES: To objectively classify shapes of the human lip vermilion in the lateral view, and to examine whether any morphologic characteristics of dentoskeletal patterns are specific to each classified lip profile pattern. MATERIALS AND METHODS: Pretreatment, lateral facial photographs of 234 Japanese women were selected. Investigators with expert knowledge of the anatomic traits of the lip vermilion in the lateral view extracted from images of the face a 13-dimensional feature vector that represented lip vermilion profile shapes. The vector quantization technique was applied to the feature vectors to mathematically optimize the number of lip vermilion profile patterns. Dentoskeletal patterns that corresponded to each classified lip shape were compared statistically. RESULTS: Seven patterns were found, and differences between patterns were notably maximized by the flatness of the anterior portion of the lip vermilion for the upper and lower lip, the position of the most protruded point of the lip vermilion, lip fissure inclination, and differences between the horizontal positions of the upper and lower lip vermilions. The dentoskeletal forms showed significant differences between classified lip vermilion profile patterns (P < .01). CONCLUSIONS: (1) Vector quantization revealed that classifying lip vermilion profiles into seven representative patterns was optimal for maximizing differences in the configuration of the lip vermilion. (2) Lip vermilion profile shapes were found to be associated with horizontal lengths of the anterior cranial base, horizontal/vertical positions, inclination and length of the mandible, and horizontal positions and labio-lingual inclinations of the upper and lower incisors.

Prognosis prediction for Class III malocclusion treatment by feature wrapping method.

OBJECTIVE: To use the feature wrapping (FW) method to identify which cephalometric markers show the highest classification accuracy in prognosis prediction for Class III malocclusion and to compare the prediction accuracy between the FW method and conventional statistical methods such as discriminant analysis (DA). MATERIALS AND METHODS: The sample set consisted of 38 patients (15 boys and 23 girls, mean age 8.53 +/- 1.36 years) who were diagnosed with Class III malocclusion and received both first-phase (orthopedic) and second-phase (fixed orthodontic) treatments. Lateral cephalograms were taken before (T0) and after first-phase treatment (T1) and after second-phase treatment and retention (T2). Based on the measurements taken at the T2 stage, the patients were allocated into good (n = 20) or poor (n = 18) prognosis groups. Forty-six cephalometric variables on T0 lateral cephalograms were analyzed by the FW method to identify key determinants for discriminating between the two groups. Sequential forward search (SFS) algorism and support vector machine (SVM) were used in conjunction with the FW method to improve classification accuracy. To compare the prediction accuracy of the FW method with conventional statistical methods, DA was performed for the same data set. RESULTS: AB to mandibular plane angle ( degrees ) and A to N-perpendicular (mm) were selected as the most accurate cephalometric predictors by both the FW and DA methods. However, classification accuracy was higher with the FW method (97.2%) compared with DA (92.1%), because the FW method with SFS and SVM has a more precise classification algorithm. CONCLUSIONS: The FW method, which uses a learning algorithm, might be an effective alternative to DA for prognosis prediction.

Determinação radiológica do índice e do tamanho craniano por mensuração dos diâmetros cranianos em uma população infantil brasileira / Radiological determination of cranial size and index by measurement of skull diameters in a population of children in Brazil

OBJETIVO: Realizar as medidas dos diâmetros cranianos obtidos por método radiológico e elaborar, por meio delas, o índice e o tamanho craniano, para comparar com as medidas dos diâmetros e os índices propostos por alguns trabalhos da literatura, principalmente os do estudo de Haas. MATERIAIS E MÉTODOS: Foram avaliados 732 pacientes sem doenças cranianas, medidos seus diâmetros cranianos e, posteriormente, formulados o índice e o tamanho craniano, que mostram as diferentes fases do crescimento do crânio, pelas medidas de tábua interna a tábua interna. RESULTADOS: O estudo comparativo das médias dos diâmetros, por medidas de tábuas internas, mostrou aumento do crescimento francamente progressivo no primeiro ano de vida para ambos os sexos e aumento menor a partir do segundo ano de vida. As médias globais dos diâmetros não apresentaram diferença significativa entre os sexos feminino e masculino. CONCLUSÃO: O índice e o tamanho craniano são bons indicadores do crescimento craniano, principalmente nos quatro primeiros anos de vida, quando o crescimento aumenta vertiginosamente no primeiro ano e, posteriormente, ocorre aumento moderado até os quatro anos de idade. Após esta idade, ocorre um leve e estável aumento e seu valor estatístico diminui. Não houve diferença estatisticamente significante, no crescimento, para ambos os sexos. Recomenda-se o uso dos valores médios dos diâmetros para ambos os sexos e sugere-se o uso do índice craniano, até os quatro anos de idade, e o tamanho craniano, após os quatro anos, sendo ideal para o acompanhamento do crescimento do crânio.

OBJECTIVE: To measure radiologically obtained skull diameters and, based on these data, calculating the cranial index and size to compare with diameter measurements and indices reported in the literature, particularly those reported by Haas. MATERIALS AND METHODS: The present study evaluated 732 individuals with no cranial disease, whose skull diameters were measured, Subsequently, the authors calculated the cranial index and size which demonstrate the different phases of the skull growth by inner-table to inner-table measurements. RESULTS: The comparative study of diameters averages by inner-table measurements has demonstrated a clearly progressive skull growth in the first year of life for both genders, and a slower growth as from the second year. Overall diameters averages did not present any significant difference between male and female individuals. CONCLUSION: Cranial index and size are good skull growth indicators, especially in the first four years of life, a period characterized by an accelerated growth in the first year and a moderate growth until the fourth year. After this age, a slight and stable growth occurs with a decrease in the statistical value. No statistically significant difference was found for both genders. It is recommended that mean diameters are utilized for both genders; and it is suggested that the cranial index is utilized until four years of age, and the cranial size after the age of four, as the ideal parameter for following up the skull growth.

The variation of head shapes in 17-20 years old native fars male in Gorgan-North of Iran

RESUMEN: El índice cefálico y la forma de la cabeza son afectados por factores geográficos, género, edad y raza. El objetivo de este estudio fue determinar el índice cefálico y la forma de la cabeza en 200 hombres nativos de Gorgan-Norte de Irán, cuyas edades fluctuaban entre 17 y 20 años de edad. El estudio descriptivo fue realizado a través de cefalometría clásica. La media y DS del índice cefálico fue 84.8 + 6.9. El 52% de los individuos era hiperbraquicéfalo, 25% braquicéfalo, 21.5% mesocéfalo y 1.5% doliocéfalo. Los individuos nativos Fars eran típicamente hiperbraquicéfalos. En comparación con otros estudios efectuados en el mundo, podemos determinar el rol del factor racial/étnico en los diámetros cefálicos.

The effect of head rotation on cephalometric radiographs.

The aim of this study was to identify the potential projection errors of lateral, postero-anterior (PA) and submentovertex (SMV) cephalometric radiographs due to head rotation in the vertical z-axis. For this investigation, a complete human dry skull of an adult was used. The skull was rotated from 0 to +/-14 degrees at 2 degree intervals. A vertical axis, the z-axis, was used as the rotational axis to expose 15 lateral and 15 PA cephalometric radiographs. The skull was tilted on each side, again at 2 degree intervals, to expose the 15 SMV films. A series of linear and angular measurements was carried out on all cephalograms. The results revealed that horizontal linear and angular measurements between the horizontal planes on lateral cephalograms were subject to changes from 16.1 to 44.7 per cent with a 14 degree rotation of the head position. For PA cephalograms, again horizontal linear measurements, particularly mandibular length, were subject to a projection error of up to 34.9 per cent with head rotation. On the other hand, projection errors were within the 3-4 per cent limit for SMV radiography. The findings indicate that: (1) linear measurements and the measurement of angles between the horizontal planes are likely to be affected by head rotation in lateral cephalograms, (2) angular measurements demonstrate smaller variations with changing rotation of the head in PA cephalograms, (3) SMV radiographs are less vulnerable to head rotation. Vertical linear measurements of lateral cephalograms and angular measurements of PA radiographs are more reliable in minimizing the projection errors associated with head rotation.

New approaches in hominoid taxonomy: morphometrics.

We report here on new cranial data relevant to hominoid taxonomic analyses, based on a study of 438 skulls belonging to 13 nonhuman living hominoid taxa. Nineteen landmarks were selected to describe the overall shape of the maxillofacial complex, in order to investigate its discriminative power in taxonomic analyses. We used a geometric morphometrics approach to depict morphological variation from the genus down to the subspecific level, and we evaluated whether our morphologic criteria are relevant to discriminating species and subspecies among living hominoids. Considering previous genetic studies, we discuss whether our results can be extrapolated to the hominin fossil record, providing a reference for species and subspecies morphologic differentiation. Our results indicate that the relative warp method, as applied to facial landmarks, provides a powerful tool to discriminate taxa down to a subspecific level. Results show a noticeable divergence of P. t. verus compared to P. t. troglodytes and P. t. schweinfurthii. According to our data, the distance between eastern and western gorilla populations as well as between Bornean and Sumatran orangutan subspecies is as great as between the two species of Pan. In the same manner, differences between Hylobates and Symphalangus are similar to those between Pan and Gorilla genera. Congruence between the morphological distances computed in this study and previous morphological and genetical studies strongly supports their relevance for morphological species recognition in paleoanthropology. Our data provide an objective standard for assessing taxonomic differences among hominoids, and will enable us to define more precisely the significance of morphological differences in the fossil record.

Proportion indices in the craniofacial regions of 284 healthy North American white children between 1 and 5 years of age.

The study's aim was to provide the normal range data on 81 anthropometric proportion indices of the craniofacial complex, separately in boys and girls between 1 and 5 years of age, supplementary to the previously published normal proportion values of the North American white population from 6 to 18 years of age. In the first age group, 17 or 18 boys and 18 or 22 girls were measured. In each age group between 2 and 5 years old, 30 boys and 30 or 31 girls were examined. The normal values of the 81 proportion indices were established with the help of 45 measurements (7 cranial, 13 facial, 4 orbital, 12 nasal, 7 labio-oral, and 2 auricular) taken from 287 healthy children. The data on the normal indices were reported in two groups: areal and interareal. The areal proportions are formed by taking measurements from one particular craniofacial region. Proportions indicating the quality of relation of measurements taken from two craniofacial regions were classified as interareal (N = 36). The basic proportions (N = 13) of the areal one show the relation between the measurements influencing the general view of each craniofacial region. The detailed analysis of the proportionality in the individual regions, carried out with the help of the other measurements within the regions, established 36 additional areal proportion indices. The recommended method of examination is to start with the basic proportions, which offers the determination of the most and least disproportionate craniofacial region, followed by a more comprehensive search for other disproportions with the help of the additional areal proportions (N = 36) and interareal proportions (N = 32).

Genetic drift and gene flow in a prehistoric population of the Azapa valley and coast, Chile.

The present paper studies the evolutionary process operating on prehistoric groups from the Azapa valley and coast (northern Chile). The sample consists of 237 crania from the Archaic Late, Early Intermediate, Middle, Late Intermediate, and Late periods. Six metric variables were used, which were transformed to eliminate the special environmental component and to increase the proportion of genetic variance. Population structure was assessed using a method based on quantitative genetic theory, which predicts a lineal relationship between average within-group phenotypic variance and group distance to the population centroid. Results indicate that 17.5% of the total variance accounts for special environmental variance. An excess in extraregional genetic flow is observed in the population corresponding to the Early Intermediate period in the valley. A reduced differentiation is observed between Archaic and Early Intermediate coastal groups, as well as between the latter and the inhabitants of the valley in the same period. Genetic differences between both areas increased substantially since the Middle period. Evidence indicates that long-range gene flow was lower on the coast than in the valley, the lowest estimated Fst being 0.0199 for the total population (coast and valley), 0.0111 for the coastal population, and 0.0057 for the valley. Results are discussed in terms of regional archeological and ethnohistorical evidence, and a microevolutionary model is presented to account for the biological history of the population.