BACKGROUND: There was a difference between the past and the present in distance from the upper incisor to the carina in children. This study was performed to evaluate the distance from the upper incisor to the carina and correlation of it with age, the weight and height in korean children from 2 to 8 years old.

METHODS: Two hundred twenty two children from 2 to 8 years old scheduled for receiving tonsillectomy or adenoidectomy were evaluated for the study by age groups (every 6 months from 2 to 8 years old). The X-ray was used for evaluation of distance from the incisor to the carina. The distance from the upper incisor to C₇ was calculated on neck lateral view and distance from C₇ to the carina was calculated on chest PA. Both distance were added and served as the distance from upper incisor to the carina.

RESULTS: The coefficient of determination of the distance from the upper incisor to the carina was highest according to height. The regression equation of the distance from the upper incisor to the carina using height was Y (cm) = 0.15 X (cm) and R² = 0.70 (Y: the upper incisor to the carina, X: the height).

CONCLUSIONS: We found that the distance from the upper incisor to the carina in children correlated with both the weight and height in children and the height was the highest correlation with distance.