Introduction: Soft-tissue facial outline has been studied by conventional cephalometric methods, and differences between the 2 sexes have been identified, mainly related to size and timing of growth. However, shape per se was not sufficiently evaluated, especially regarding variability, age-related changes, and sexual dimorphism. The purpose of this study was to evaluate shape variability and sexual dimorphism of the soft-tissue outline by using morphometric methods.
Methods: Pretreatment lateral cephalograms from 170 consecutive patients (82 male, 88 female) aged 7 to 17 years were used. Fifteen skeletal and 22 soft-tissue landmarks were digitized and processed with Procrustes superimposition and principal component analysis. The principal components (PCs) of the soft-tissue shape were analyzed in relation to age and sex.
Results: The first 8 PCs explained approximately 90% of the total shape variability. The first coefficient (PC1) related to lip, nose, and chin prominence and included 36% of total shape variability. It was significantly correlated to age, but with a low coefficient of determination (r2 = 13%). The second coefficient (PC2) related to facial convexity and explained 18% of shape variability. The next 2 coefficients were mainly related to lower lip shape. Statistically significant sexual dimorphism was detected, but the overall shape differences between the average profiles of boys and girls were minor and barely detectable visually. Shape dimorphism was present both before and after the age of 12 years.
Conclusions: Shape variability related mainly to relative lip protrusion, convexity of the face, and lower lip shape. Shape differences between the sexes seemed to exist even before the pubertal growth spurt, but they were small. Age changes in shape appeared more significant.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1016/j.ajodo.2005.06.031 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Bistable Functions and Signaling Motifs in Systems Chemistry: Taking the Next Step Toward Synthetic Cells.
Acc Chem Res
January 2025
Department of Chemistry, Ben-Gurion University of the Negev, Be'er Sheva 84105, Israel.
ConspectusA key challenge in modern chemistry research is to mimic life-like functions using simple molecular networks and the integration of such networks into the first functional artificial cell. Central to this endeavor is the development of signaling elements that can regulate the cell function in time and space by producing entities of code with specific information to induce downstream activity. Such artificial signaling motifs can emerge in nonequilibrium systems, exhibiting complex dynamic behavior like bistability, multistability, oscillations, and chaos.
View Article and Find Full Text PDFRock strength controls erosion in tectonically dead landscapes.
Sci Adv
January 2025
Instituto de Geociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
Interactions among tectonics, climate, and lithology shape the Earth's surface. In regions dominated by tectonic quiescence and climate stability, the role of rock strength related to lithology, and its role in landscape evolution, can be most clearly perceived. We leverage these qualities in a unique field site by integrating topographic data, erosion rates, and a large suite of rock strength measurements to quantify the relationship between bedrock strength and erosion rates along a 200-km section of the southeast coast of Brazil where climatic and tectonic variability are minimal.
View Article and Find Full Text PDFCorrelation between the white blood cell/platelet ratio and 28-day all-cause mortality in cardiac arrest patients: a retrospective cohort study based on machine learning.
Front Pharmacol
January 2025
Department of Neurological Rehabilitation, Jiangbin Hospital of Guangxi Zhuang Autonomous Region, Nanning, China.
Objective: This study aims to evaluate the association between the white blood cell-to-platelet ratio (WPR) and 28-day all-cause mortality among patients experiencing cardiac arrest.
Methods: Utilizing data from 748 cardiac arrest patients in the Medical Information Mart for Intensive Care-IV (MIMIC-IV) 2.2 database, machine learning algorithms, including the Boruta feature selection method, random forest modeling, and SHAP value analysis, were applied to identify significant prognostic biomarkers.
Spermidine Recovers the Autophagy Defects Underlying the Pathophysiology of Cell Trafficking Disorders.
J Inherit Metab Dis
January 2025
Synaptic Metabolism and Personalized Therapies Lab, Institut de Recerca Sant Joan de Déu, Department of Neurology and MetabERN; Esplugues de Llobregat, Barcelona, Spain.
Cell trafficking alterations are a growing group of disorders and one of the largest categories of Inherited Metabolic Diseases. They have complex and variable clinical presentation. Regarding neurological manifestations they can present a wide repertoire of symptoms ranging from neurodevelopmental to neurodegnerative disorders.
View Article and Find Full Text PDFNiche partitioning in a periphyton metacommunity peaks at intermediate species richness in midsized rivers.
Ecology
January 2025
Department of Ecology, University of Innsbruck, Innsbruck, Austria.
The trait-based partitioning of species plays a critical role in biodiversity-ecosystem function relationships. This niche partitioning drives and depends on community structure, yet this link remains elusive in the context of a metacommunity, where local community assembly is dictated by regional dispersal alongside local environmental conditions. Hence, elucidating the coupling of niche partitioning and community structure needs spatially explicit studies.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!