The objective of this study is to verify the changing habits and their maintenance after using cognitive behavioral therapy, exploring factors that may be associated with these stages and the moment in which they occur.

The objective of this clinical trial is to verify the time until changing habits and their maintenance after using cognitive behavioral therapy, exploring the following factors that may be associated with these stages and the moment in which they occur:

• Evaluate the cost-effectiveness of guidance based on cognitive behavioral therapy in relation to changes aimed at oral hygiene and diet habits, through a before and after study;
• Investigate individual and contextual preferences associated with adherence and maintenance of behaviors associated with oral health (diet and oral hygiene) through a Discrete Choice Experiment (DCE)
• Measure the effect of retaining hygiene and diet guidance on pairs who did not submit the calendar and on those who submitted the calendar.

Inclusion Criteria:

• Twin children born at the Hospital de Clínicas de São Paulo between 2007 and 2014;
• Children whose mothers were followed up at the Multiple Pregnancy Unit;
• Guardians who sign the informed consent form;
• Children who sign the assent form.

Exclusion Criteria:

• Children whose families that cannot be contacted by phone call, email, or social media;
• Children with medical or psychological conditions that prevent safe participation in the dental research.

Data will be collected on pregnancy, parental sociodemographics (age, sex), alloparental care, and twin characteristics (age, sex, zygosity), using questionnaires and registry data (birth weight, ICU admission, chorionicity, gestational age, fetal growth, complications). Caries lesions and indicators of physical, cognitive, and emotional development will be monitored. Behavioral and physiological data will be collected before and during a dental procedure. Instruments include the Danish Twin Registry Zygosity Questionnaire, Environmental Sensitivity, Socialization Goals, Alabama Parenting, Twin Relationship, Childhood Adversity, Quality of Life, MCDAS-f, Emotion Regulation Checklist, and identity fusion. Additional data: caries detection (ICDAS), physical (height, weight), cognitive (Raven), figure drawings, videos, facial temperature (thermal camera), voice recordings, and saliva swabs. Metadata will follow USP's Open Access Policy, including DOI, title, authors, and deposit details.

baseline, 6M, 12M, 18M, 24M

Data will be collected on pregnancy, parental sociodemographics (age, sex), alloparental care, and twin characteristics (age, sex, zygosity), using questionnaires and registry data (birth weight, ICU stay, chorionicity, gestational age, fetal growth, complications). Caries lesions and indicators of physical, cognitive, and emotional development will be monitored. Behavioral and physiological data will be gathered before and during dental procedures. Instruments include Zygosity Questionnaire, Environmental Sensitivity, Socialization Goals, Alabama Parenting, Twin Relationship, Childhood Adversity, Quality of Life, MCDAS-f, Emotion Regulation, and identity fusion. Additional data: caries detection (ICDAS), physical (height, weight), cognitive (Raven), figure drawings, videos, facial temperature (thermal camera), voice recordings, and saliva swabs. Metadata will follow USP Open Access Policy with DOI, title, authors, keywords, funding, and deposit info.