A morphometric analysis of developmental instability in children born with unilateral cleft lip and palate

Symmetry and fluctuation of cell movements in neural crest-derived facial mesenchyme

In the face, symmetry is established when bilateral streams of neural crest cells leave the neural tube at the same time, follow identical migration routes and then give rise to the facial prominences. However, developmental instability exists, particularly surrounding the steps of lip fusion. The causes of instability are unknown but inability to cope with developmental fluctuations are a likely cause of congenital malformations, such as non-syndromic orofacial clefts. Here, we tracked cell movements over time in the frontonasal mass, which forms the facial midline and participates in lip fusion, using live-cell imaging of chick embryos. Our mathematical examination of cell velocity vectors uncovered temporal fluctuations in several parameters, including order/disorder, symmetry/asymmetry and divergence/convergence. We found that treatment with a Rho GTPase inhibitor completely disrupted the temporal fluctuations in all measures and blocked morphogenesis. Thus, we discovered that genetic control of symmetry extends to mesenchymal cell movements and that these movements are of the type that could be perturbed in asymmetrical malformations, such as non-syndromic cleft lip.

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Highlighted Article: Live imaging of the chick embryo face followed by mathematical analysis of mesenchymal cell tracks captures novel fluctuations between states of order/disorder as well as symmetry/asymmetry, revealing developmental instabilities that are part of normal morphogenesis.

Season of birth and biomarkers of early-life environment

OBJECTIVE

Early-life conditions play an important role in human development, affecting health status and survival. Conditions in utero partly depend on the external environment and thus vary in relation to the season of birth. The aim of this study was to investigate if people born in different seasons of the year differ in values of biomarkers that reflect conditions during fetal development.

METHODS

The study was conducted among Polish rural women recruited at the Mogielica Human Ecology Study Site. The participants were 234 women aged 45 to 92 (mean = 60.2; SD = 10.44). The indicators of early-life environment analyzed in the study were: Absolute Finger Ridge Count (AFRC), the difference between mean number of ridge counts in both thumbs and both little fingers (Md15), overall facial fluctuating asymmetry (OFA), central facial asymmetry (CFA), right and left hand 2D:4D.

RESULTS

Values of biomarkers of fetal development did not vary among groups of women born in different seasons of the year.

CONCLUSIONS

Lack of differences in values of biomarkers according to birth season may indicate that: (a) season of birth is not a good indicator of early-life conditions; (b) tested biomarkers do not reliably reflect the prenatal environment; (c) season of birth does not fully overlap with the sensitive periods of biomarker development and thus fails to capture differences in developmental conditions.

What Do We Find Attractive about the Face?: Survey Study with Application to Aesthetic Surgery

The appearance of the face is one of the most important factors influencing our perception of beauty. However, few studies have attempted to quantitate what one perceives as beauty. Therefore, this study was conducted with the goal of providing physicians with anatomical data that demonstrate which facial traits most influence our perception of one's attractiveness. In the first phase of the study, faces of 60 participants (30 males and 30 females) were photographed. Next, the photographs were shown to another group of 120 study members (60 males and 60 females), who evaluated the facial features using a Visual Analogue Scale. The highest rated facial parts were then measured using the ImageJ program. In men, the most attractive parts of the face were Type 1:2 lips, a Type IV nose of medium width, blue eyes, brown hair, and a very narrow face. Among females, the most attractive parts of the face were Type 2:1 lips, Type III and V noses of medium width, dark brown eyes, blonde hair, and a narrow face. This is the first study in which the most aesthetically important facial parts have been comprehensively examined. The results obtained in our study show a higher degree of representativeness compared to other studies due to a different methodological approach and can be used as an aesthetic guide and can help in the planning of aesthetic surgery such as lip augmentation and rhinoplasty. Clin. Anat. 33:214-222, 2020. © 2019 Wiley Periodicals, Inc.