Brace yourselves, teenyboppers. On the set of his latest film, “The Fight Club” (directed by “Seven”‘s David Fincher), Brad Pitt has undertaken a decidedly unsexy form of Method acting, according to Entertainment Weekly magazine. Pitt voluntarily chipped out pieces of his front teeth to play a man who brawls in illegal underground bouts. No stranger to cosmetically glamming down his pinup looks (remember his grotesque pried-open eye in “12 Monkeys”?), Pitt visited a dentist for his new snaggletoothed grin. “Brad1s willing to go to great lengths for a character,” says Pitt1s publicist, Cindy Guagenti. “Most people hate to go to the dentist.” Once filming is finished at the end of October, she stresses, the sex symbol plans to get his pearly whites restored. –Chris Nashawaty