Changes

Kayaba ''et al''. (1996) reported that before six months of age, no boy had a retractable prepuce; 16.5 percent of boys aged 3-4 had a fully retractable prepuce.<ref name="kayaba1996">{{REFjournal

}}</ref> Ko ''et al''. (2007) examined 59 newborn Taiwanese boys. Not one had a retractable foreskin.<ref name="ko2007">{{REFjournal

[[File:Kayaba.jpg|left|frame|Percentage of boys with tight ring totally non-retractile foreskin according to Kayaba ''et al''.]]<br clear="all">

[[Jakob Øster]], a Danish physician who conducted school examinations, reported his findings on the examination of school-boys in Denmark, where circumcision is rare.<ref name="Øster1968">{{OesterJ 1968}}</ref> Øster (1968) found that the incidence of fusion of the foreskin with the glans penis steadily declines with increasing age and foreskin retractability increases with age.<ref name="Øster1968"/> Kayaba ''et al''. (1996) also investigated the development of foreskin retraction in boys from age 0 to age 15.5 Kayaba ''et al''. also reported increasing retractability with increasing age. Kayaba ''et al''. reported that about only 42 percent of boys aged 8-10 have fully retractile foreskin, but the percentage increases to 62.9 percent in boys aged 11-15.<ref name="kayaba1996" /> Imamura (1997) reported that 77 percent of boys aged 11-15 had retractile foreskin.<ref name="imamura1997" /> Thorvaldsen & Meyhoff (2005) conducted a survey of 4000 young men in Denmark. They reported that the mean age of first foreskin retraction is 10.4 years in Denmark.<ref name="Thorvaldsen">{{REFjournal

Ko ''et al''. (2007) examined 1145 Taiwanese boys aged 7 to 13. Ko ''et al''. reported:

The findings reported by Ko ''et al."' are consistent with the findings reported by Øster (1968), by Kayaba ''et al''. (1996), and by Thorvaldsen & Meyhoff (2005)