Newcomer Lou Pucci has a wounded-looking face you can't help fixating on. Too bad an actor with such animal magnetism is trapped in all-too-familiar surroundings in Thumbsucker. His obsessive, oedipally conflicted Justin is a true indie-film staple: the odd-duck teen trying to find his place in a bizarro suburban world. For inspiration, the film dips into the bag of tics from Walter Kirn's novel, but the loony yet incisive humor that defined the book is often overshadowed by mopey sentiment. (The Elliott Smith-laced soundtrack says it all.) It's a trip to see Vince Vaughn ditch his frat-boy cool to play a debate coach and a good-natured Keanu Reeves as a Zen-master orthodontist. Something just got lost in adaptation. EXTRAS Kirn, however, gives director Mike Mills his blessing: In a téte-á-téte, they massage each other's egos and share the challenges of bringing ''uncomfortable'' content to life. Then Mills flies solo in a self-deprecating commentary, revealing his affinity for simple, repetitive camera work and The Ice Storm (''I love the way the kids and adults are treated at the same level''). Plus: a director's blog for the DVD-ROM-savvy and a by-the-numbers mini-doc.