Aim: To analyze and report the type of relation present between dental caries 
and body mass index (BMI)-for-age among schoolchildren in south valley region of 
Arab Republic of Egypt.. Subjects and methods: We conducted a cross-sectional 
observational study of 262 aged three to 15 years with clinically recorded dental 
caries. The World Health Organization diagnostic criteria for BMI percentile was 
used to evaluate and record dental caries clinically. The obtained results were plotted 
on age- and gender-specific percentile curves by the Centers for Disease Control and 
Prevention and categorized accordingly. Results: Data were fed to the computer and 
analyzed using IBM SPSS software package version 20.0. The mean dmft and DMFT 
for the whole sample were (2.5 ± 2.1 and 1.2± 1.4) respectively Conclusion: This study 
showed that unhealthy family functioning was associated with dental caries among 
young children. Family functioning partly explained the relationship between family 
SES and childhood dental caries