Aim: This study aimed to detect the status of eruption of primary teeth and BMI among children aged 6 to 36 months having low weight at birth compared with children with normal weight.

Methodology: A total of 81 children (38 children in the lower birth weight group LBW and 43 children in the normal weight group NBW) participated in this study. Besides clinical examination, data was collected via a personal interview with the children's mothers or guardians. For every child, the weight and height were measured, the BMI was calculated, and the type and erupted teeth numbers were obtained. The collected data were finally statistically analyzed.

Results: No statistically significant differences (p>0.05) in the number of erupted teeth among the two groups at different ages. Regarding the time of the first erupted tooth, the LBW group had a significantly higher value than the NBW group (p=0.033), denoting a later eruption date. No statistically significant difference was found among both groups (p>0.05) regarding weight, length, and body mass index. There was a positive correlation between children's body mass index (BMI) and erupted teeth numbers. No statistically significant relationship existed between BMI and the timing of the emergence of the first tooth. (p>0.05).

Conclusions: Birth weight did not affect the erupted teeth numbers but affected the time of eruption of the first primary tooth. Regarding eruption status, normal birth weight (NBW) children have a higher percentage of cases with normal eruption than low birth weight (LBW) children.