Simplify the following text for a Grade 10 native English-speaking person.
Original: Petticoats were revived by Christian Dior in his full-skirted `` New Look '' of 1947 and tiered , ruffled , stiffened petticoats remained extremely popular during the 1950s , especially with teenage girls .
Simplified: Petticoats were revived by Christian Dior in his full-skirted New Look of 1947 . Tiered , ruffled , stiffened petticoats remained extremely popular during the 1950s , especially with teenage girls .