Is there a correlation between dental caries and body mass index-for-age among adolescents in Iran?

Obesity in adolescents is a public health problem and is steadily increasing in many countries. The aim of this study was to investigate the association between age-and gender-specific body mass index (BMI-for-age) and dental caries among adolescents aged 12 -15 years in Rafsanjan, Iran.

Following ethical approval, 747 students aged 12-15 years were randomly selected from 12 state and private secondary schools in Rafsanjan, Iran. The DMFT index (following World Health Organization criteria) was used to assess the subjects' previous and existing dental caries experience. The BMI (Body Mass Index) percentile was calculated using BMI-for-age criteria as underweight (< 5th percent), normal-weight (5th-85th percent), at risk of being overweight (> 85th and < 95th percent) and overweight (> or = 95th percent).

Of 353 males and 394 females examined, 7.5% were underweight, 72.8% were normal-weight, 13.8% were at risk of being overweight, and 5.9% were overweight. The mean DMFT was 2.83. There was no significant difference between DMFT scores amongst the BMI-for-age groups (underweight = 2.91, normal-weight = 2.92, at risk of overweight = 2.54, overweight = 2.34, p > 0.05). However, males were more likely to have caries than females (11% of males were caries-free, in comparison to 20.6% of females; p < 0.05).

Almost one in five adolescents (19.7%) examined were deemed to be at risk of being overweight, or were classified as overweight. There was no association between DMFT scores and BMI-for-age scores.