The gross-out horror comedy Teeth is so outrageously unnerving that the picture scares itself. The movie stars Jess Weixler as Dawn, a proudly virginal high schooler who discovers that she has teeth … well, where there shouldn’t be any. They emerge, so to speak, along with Dawn’s burgeoning, hesitant sexuality. In between the scenes of over-the-top comic violence (John Wayne Bobbitt will want to stay far away from this one), director Mitchell Lichtenstein hits some smart, satirical notes about the hysterical way our society deals with teen sexuality. I only wish Lichtenstein had made the movie more about Dawn than about the piggish men she encounters. As she quickly transforms from naïve innocent to avenging feminist, we learn more about her victims than about what’s going on in her head. Like the puritans he means to lampoon, Lichtenstein effectively neuters Dawn’s sexuality. We hardly get a sense of what role her desire plays in all this. Dawn may be the heroine of Teeth, but in the end the movie is still a little afraid of her.