The purpose of the present study was an assessment of differences between boys and girls in the process of emergence of primary teeth. This paper also provides updated data on the timing and sequence of primary tooth emergence in Polish children. The research were conducted in the years 2004–2008, and covered 865 children (437 boys and 428 girls) aged 3 to 36 months from all nursery and randomly selected “Healthy Child Clinics” in Lodz (central Poland). The first and last primary tooth emerged, on average: in boys at 6.24 months and 24.75 months respectively; in girls at 7.07 months and 24.21 months respectively. All incisors and the first upper molars erupted significantly earlier in boys. Typical order of teeth emergence – central incisor, lateral incisor, first molar, canine, second molar – was observed in 86.36 % of boys and in 89.47 % of girls. The interdependence between the morphological and the dental criterion of biological maturity during the completion of primary teeth was very strong in both sexes (stronger in boys). The regression equations for the estimation of the number of erupted primary teeth based on child's chronological age, body height and body mass were proposed separately for boys and for girls.

Several studies have shown that sex estimation methods based on measurements of the skeleton are specific to populations. Metric traits of the upper long bones have been reported as reliable indicators of sex. This study was designed to determine whether the four long bones can be used for the sex estimation of an historical skeletal population from Radom (Poland). The material used consists of the bones of 169 adult individuals (including 103 males and 66 females) from the 18th and 19th centuries. Twelve measurements were recovered from clavicle, humerus, radius and ulna. The initial comparison of males and females indicated significant differences in all measurements (p < 0.0001). The accuracy of sex estimation ranged from 68% to 84%. The best predictor for sex estimation of all the measurements in Radom’s population was the maximum length of the radius (84%), and the ulna (83%), and the vertical diameter of the humeral head (83%). The Generalized Linear Model (GLM) detected the strongest significant relationship between referential sex and the vertical diameter of the humeral head (p < 0.0001), followed by the maximal length of the ulna (p = 0.0117). In other measurements of the upper long bones, GLM did not detect statistically significant differences.

Background: The research aimed to determine how socioeconomic factors influence the body structure and health behaviors of children in a suburban commune. Methods: Data from 376 children aged 6.78 to 11.82 years from Jabłonna, Poland, were analyzed. A questionnaire was used to gather information regarding the socioeconomic status and dietary habits of these children, and physical measurements such as height, weight, pelvic width, shoulder width, chest, waist, hip, and arm circumferences, and three skinfolds were taken. Hip index, pelvi-acromial index, Marty’s index, BMI (body mass index), WHR (waist–hip ratio), and the sum of three skinfolds were calculated. One-way analysis of variance, Student’s t-test, and X² test with p < 0.05 were used. Results: The size of the family and the level of education and occupation of the fathers had a significant impact on the body proportions of the children. Children from larger centers with more educated parents were seen to have healthier eating habits and higher levels of physical activity, and their parents were less likely to smoke cigarettes. Conclusions: It was concluded that the development environment of the parents, such as their level of education and profession, play a more important role than the size of birthplace.

The secondary sex ratio (SSR) is a widely used descriptor that reflects the living conditions and health status during pregnancy. The aim of study was to assess the impact of maternal factors, season of birth, and air pollution with the heating season on the sex ratio at birth in the Subcarpathian population from the Krosno district, Poland. A retrospective study involving 11,587 births was occurred at the John Paul II Podkarpackie Province Hospital in Krosno between 2016 and 2020. Sex of the newborn, the season of their birth, as well as the maternal age, birth order, the interval between births, and the season of birth were analysed. Furthermore, the relationship between the SSR and the level of air pollution during the heating season was investigated. To determine the significance of differences in sex ratios, chi-square analysis and multifactorial regression were used, with a significance level set at p < 0.05. At the chi-square level, all the studied factors indicated a statistically significant relationship with the SSR. However, the regression model used shows that maternal age and birth order were the most important factors in shaping the SSR in the study group.

Overweight and obesity are significant public health concerns, affecting pregnant women and potentially leading to numerous complications for both maternal and neonatal health. The aim of this study is to estimate how pre-pregnancy overweight and obesity, as well as gestational weight gain, influence pregnancy outcomes and neonatal health in Poland. The study material consisted of data from 2878 women aged 16–46 years from hospitals in Warsaw and Krosno. The analysis included data on the course of singleton pregnancies and the biological condition of the newborns, correlated with pre-pregnancy Body Mass Index (BMI) and gestational weight gain (GWG), which were compared to the standards set by the Institute of Medicine (IOM). Factor that significantly influences pre-pregnancy BMI and GWG is the number of pregnancies. For first-born women pre-pregnancy BMI was significantly lower than that of women giving birth for the second, third and subsequent times (ANOVA p < 0.0001), at the same time, the increase in weight in this group was the greatest (ANOVA p < 0.0001). The study found that pre-pregnancy BMI correlates more strongly with the occurrence of gestational diabetes than GWG above IOM recommendations (regression: p < 0.0001, R = 0.112 vs. p < 0.0001, R = 0.104). Analogous correlations were observed for the incidence of gestational hypertension and termination of pregnancy by caesarean section. Birth weight and length are significantly affected by both pre-pregnancy BMI and GWG but the effect of weight change is stronger (birth weight - pre-pregnancy BMI regression p < 0.0001, R = 0.116; GWG p < 0.0001, R = 0.248; birth length - pre-pregnancy BMI regression p < 0.0001, R = 0.087; GWG p < 0.0001, R = 0.180). An analogous relationship was observed for the presence of macrosomia. For APGAR scores, an inverse relationship was observed; while GWG did not show a significant relationship with the first minute score, perinatal neonatal status was significantly related to the mother’s pre-pregnancy BMI (regression p = 0.0006). Similarly, pre-pregnancy maternal BMI > 25 significantly increased the odds of perinatal injury and breastfeeding difficulties.

Objectives: The aim of this study was to assess whether the time of vitamin D supplementation after birth, season of birth and the type of feeding affected current body weight, body height and BMI among children aged 3-56 months from two cohorts. Additionally, it was analysed whether birth weight and birth length correlated with current BMI, body height and body weight in both cohorts of children. Methods: The study material included 1930 children from the two cohorts, measured in two following periods: 1993-1997 and 2004-2008. Finally 849 healthy individuals aged 3-56 months were included in the analysis. Multiple stepwise regression model was applied to find the group of the most important variables explaining current body weight, body height and BMI. Moreover generalized linear models for two way interactions were used. Results: The season of birth, time of supplementation of vitamin D, but also birth weight and length might affect current body weight. Individuals' height could be associated with birth length and the season of birth. BMI value was probably regulated by birth length and weight. Furthermore, interactions between the time of vitamin D supplementation and season of birth and also between the time of vitamin D supplementation and type of feeding resulting in variation of body weight and BMI in the first years of life were also observed. Conclusions: The study underlines the importance of a supplementation of vitamin D, season of birth and birth weight and length in current weight, height and body proportion in the first 3.5 years of life.