The aim of this study was to evaluate some aspects of the pathogenesis and diagnosis of teething in newborns based on the study of the dynamics of estrone in breast milk and the saliva of a newborn. 78 practically healthy lactating women with obesity-38 and 30 who were not obese were examined, as well as their newborns. Object of study, saliva and blood plasma. It was revealed that the hormonal profile of a newborn in saliva with a change in metabolism in lactating women can undergo certain changes. As lactation develops in women with excess body weight, hormone estrone undergo intensive elimination from milk, which leads to a decrease in its content in breast milk, which can affect metabolic processes in the newborn's dentofacial system.