Physical and behavioral development of twin children: behavioral and physiological indicators of environmental sensitivity in an anxiety context

Abstract

Studies in twins allow the evaluation of factors associated with oral health problems that may be related to genetics, prenatal factors, and the environment. The aim of this study is to assess the influence of zygosity and fetal parameters on dental caries, outcomes related to oral health, and differences in oral structures in twins. A historical cohort with twins born at the Hospital das Clínicas (HC) from 2007 to 2014 will be conducted. These children will be invited, through their guardians, to attend the School of Dentistry at USP (FOUSP) to participate in the research. Diseases and alterations present in everyday life will be evaluated, including dental caries, traumas, defects in enamel formation such as fluorosis and Molar-Incisor Hypomineralization, malocclusion, and bruxism, as well as differences in oral structures. Data related to prenatal and perinatal factors, as well as zygosity, will be collected from the guardians. Demographic, socioeconomic, and childhood-related data will be collected through a questionnaire. The twins will undergo a clinical examination to assess the outcomes, a diet questionnaire, intraoral scanning to evaluate metric and morphometric differences in dental elements, and palatal rugoscopy. Multilevel regression analyses (the first level related to the individual, and the second level related to the pair of siblings) will be conducted to investigate the association of all outcomes with zygosity, prenatal and perinatal data, and other variables. Geometric morphometric analysis will be performed using the ImageJ® program, and the results will be analyzed through integrated programs.