Sexually Dimorphic Ontogenetic Trajectories of Frontal Sinus Cross Sections

In this paper, we analyze a large published data set1 of cross sections of frontal sinuses of 3 to 11-year-olds (105 males and 87 females) from Central Europe to investigate several issues relating to frontal sinus ontogeny. Despite a large variation in every one year age cohort, we detect no asymmetry of the left average versus the right average frontal sinus lobe cross-sectional areas in the population, neither for males nor for females. The growth rate is shown to be nonuniform and differs between males and females. We demonstrate the use of a sigmoid function interpolation to characterize one aspect of ontogeny, namely, the functional relation between the cross-sectional area of the frontal sinus and the age of the individual. Ontogenetic trajectories of these crosssectional areas are remarkably well modeled by a sigmoid function (logistic curve) with suitably estimated parameters for development up to an age of 11 years (females) and 9 years (males). However, these developmental curves also reliably predict the average adult cross-sectional area at age 19 (99% for females, 95% for males). Apart from possible inadequacies of the data set, we also discuss the possibility of heterochrony in the ontogenetic trajectory before versus after puberty

Orofacial Analysis on the Adriatic Islands: 1. The Island of Hvar as a Model for Odontogenetic Researches

This paper presents a preliminary orofacial analysis of a subadult population of Hvar, a Croatian island in the Adriatic. Its population represents one of the last genetic isolates in Europe and has therefore been the object of intensive crossdisciplinary research over the last 30 years.We focussed on the coefficient of endogamy on the one hand and malocclusal-related caries on the other hand, and expected differences in the latter between subgroups of the population. We analyzed 224 dental casts from children all over the island and found multiple caries in approximal surfaces in 55 percent of the children, but no significant differences between the subpopulations. Instead, significantly more caries affection was found in the boys than in the girls. The percentage of general caries affection is fairly high, even when compared to other isolated populations; it may be due to environmental influence. This would be consistent with the other results, which have putatively been caused by complex environmental influences and not solely by genetic components

Virtual anthropology: The digital evolution in anthropological sciences

The discovery and explanation of differences among organisms is a major concern for evolutionary and systematic biologists. In physical anthropology, the discrimination of taxa and the qualitative and quantitative description of ontogenetic or evolutionary change require, of course, the analysis of morphological features. Since the 1960s, a remarkable amount of fossil material was excavated, some of it still awaiting a detailed first analysis, some of it requiring re-examination by more developed methods. While the fossil record grew continuously, a revolution in anthropological research took place with advances in computer technology in the 1980s: a handful of innovative researchers working in specialized anthropology laboratories or medical departments developed the methodological inventory needed to extract critical information from subjects in vivo and from fossilized remains. A considerable part of this information is preserved in the physically heretofore inaccessible interior of anatomical structures. Virtual Anthropology (VA) is a means of making them visible and measurable. Thus, VA also allows access to `hidden' landmarks; in addition, the large number of semilandmarks accessible on the form enhances the power of Geometric Morphometrics analysis. Furthermore, the density information in volume data allows manipulations such as segmentation, impossible with the real, physical object. Moreover, metric body measurements generally, and cranial measurements specifically, are also an important source of information for the analysis of the ontogenetic development of the skeletal system, and-last but not least-for clinical use (e.g., operation planning, operation simulation, prothetics). Thus, there developed a fruitful interdisciplinary cooperation between statistics, medicine, and physical anthropology

Cranial integration in Homo: Singular warps analysis of the midsagittal plane in ontogeny and evolution

This study addresses some enduring issues of ontogenetic and evolutionary integration in the form of the hominid cranium. Our sample consists of 38 crania: 20 modern adult Homo sapiens, 14 subadult H. sapiens, and four archaic Homo. All specimens were CT-scanned except for two infant H. sapiens, who were imaged by MR instead. For each specimen 84 landmarks and semilandmarks were located on the midsagittal plane and converted to Procrustes shape coordinates. Integration was quantified by the method of singular warps, a new geometric-statistical approach to visualizing correlations among regions. The two classic patterns of integration, evolutionary and ontogenetic, were jointly explored by comparing analyses of overlapping subsamples that span ranges of different hypothetical factors. Evolutionary integration is expressed in the subsample of 24 adult Homo, and ontogenetic integration in the subsample of 34 H. sapiens. In this data set, vault, cranial base, and face show striking and localized patterns of covariation over ontogeny, similar but not identical to the patterns seen over evolution. The principal differences between ontogeny and phylogeny pertain to the cranial base. There is also a component of cranial length to height ratio not reducible to either process. Our methodology allows a separation of these independent processes (and their impact on cranial shape) that conventional methods have not found