抄録
This report dealt with 12-year-9-month old monozygotic twin brothers who had follicular cysts symmetrically in both canine regions of upper jaw. The following results were obtained.
1) The roentgenographs and the histological findings of all cyst walls exhibited typical characteristics of follicular cyst.
2) The size and shape of four cysts resemble each other.
3) Since all four cysts occurred on upper permanent canines which had been reported to be the teeth most frequently involved in follicular cysts, these cysts were thought to develop because of the pressure exerted by the tissue around the canines. However, follicular cysts occurred bilaterally and symmetrically in the monozygotic twin, which suggested twin brothers had some genetic factor that influenced these occurrences.
