A STUDY ON THE ORDER OF APPEARANCE OF DECIDUOUS TEETH

Abstract

In 1959 a group of 333 infants in Tokyo, off first-or second-born, were subject to collective dental examination, and the first-born and second-born groups were compared as to the eruption of deciduous teeth and decayed teeth (def). The results were as shown below:
As for the eruption of deciduous teeth, the firstborn group had less teeth appearing than the secondborn group at each age, particularly at one and five. In other words, the first-born are slower than the second-born in having deciduous teeth and more-liable to lose them latter.
Generally, decayed teeth were found more of ten among the second-born proximal surface and distall proximal surface of the lower lateral milk incisor, and the labial and buccal surface infour-year-olds.