Ontogeny of facial dimorphism and patterns of individual development within one human population

Abstract

Based on a longitudinal study of radiographs of the Denver Growth Study, we investigated the morphological development of individual and gender differences in the anterior neurocranium, face, and basicranium. In total, 500 X-rays of 14 males and 14 females, each with 18 landmarks and semilandmarks, were digitized and analyzed using geometric morphometric methods. Sexual dimorphism in shape and form is already present at the earliest age stage included in the analysis. However, the nature of dimorphism changes with age. Four factors apper to contribute to cranial sexual dimorphism in human postnatal development: 1) initial, possibly prenatal, differences in shape; 2) differences in the association of size and shape; 3) male hypermorphosis; and 4) some degree of difference in the direction of male and female growth trajectories. Studying changes in individuals, we find a low correlation between newborn and adult morphology, while 3-year-olds already show a high correlation with their adult form. We conclude that the adult pattern of interindividual difference in facial form in a single human population is established within the first few years of life.

Modularity and integration in ontogeny of the middle facial skeleton in two West African monkey species: collared mangabey (Cercocebus torquatus) and olive colobus (Procolobus verus)

“…Despite it there are some challenging questions about any of these modules. For example, the eyeball undoubtedly plays a great role in early morphogenesis of the face integrating surrounding structures molar and premolar emergence and pubertal growth spurt (Enlow, 1975;Richtsmeier et al, 1993;Funatsua et al, 2006;Bulygina et al, 2006). We believe that considering single bones growth processes may add some additional arguments for the long-standing discussion about a relative importance of early pre-and perinatal growth versus postnatal growth in the facial skeleton ontogeny (Richtsmeier et al, 1993;OHiggins & Jones, 1998;Collard & OHiggins, 2001;Ponce de Leon & Zollikofer, 2001;Ackermann & Krovitz, 2002;OHiggins & Collard, 2002).…”

“…Both the premaxilla and the upper part of the nasal bones grow rapidly during the gestation so a morphological pattern of the midline facial structures is nearly developed by the end of the first year of life (Sysak, 1960;Schultz, 1963;Mooney & Siegel, 1986;Richtsmeier et al, 1993;Franciscus, 1995). Human infant skulls from different populations can be classified nearly as correctly as the adults (Vidarsdóttir et al, 2002), and an individual pattern of the facial skeleton is also determined by the age of 3 years (Bulygina et al, 2006). Taking into account small size of the maxilla at this age the abovementioned differences can be attributed predominantly to the premaxilla and the nasalia morphology.…”

“…In the oral module its lower part, alveolar process, is undoubtedly affected by masticatory loadings but there are strong reasons to suppose an influence from the other functional matrix, nasal septum, onto its upper structures the palate and the nasal spine area (Latham, 1970;Mooney & Siegel, 1986;Depew et al, 2005;Holton et al, 2010Holton et al, , 2011. The shape of the masticatory module depends not only on masticatory cyclic strain but also on the general somatic growth factors (Collard & OHiggins, 2001;Hallgrimsson et al, 2004;Bulygina et al, 2006;Funatsu et al, 2006) as well as on the shape of the cranial base (Bunak, 1960;Richtsmeier et al, 1993;Liebeman et al, 2000). A relatively low level of integration in these functional modules was found in many studies (Cheverud, 1982;Cardini & Elton, 2008a;Adams et al, 2011) and demonstrates that such an approach captures just a part (even though a very important part) of information about modularity of the facial skeleton and stimulates a search for new ways of separation of the whole structure into modules.…”

Cross-cultural effects of color, but not morphological masculinity, on perceived attractiveness of men's faces

“…degree of anatomical masculinization; Bulygina et al, 2006) should be of less importance to females than other more condition-dependent cues to current health. Moreover, this tendency should be more pronounced in animals with long lifespans and slow reproduction, such as humans .…”

Age Effect in the Morphological Traits Performance for Sex Determination in Human Skulls and Mandibles

“…(Blanchette et al, 1996;Suazo et al, 2007) Bulygina et al (2006) note that sexual dimorphism in subjects presents at an early age. They found little correlation between morphology of newborn and adult subjects.…”