Dogtooth [DVD] / Directed by Yorgos Lanthimos

Enhanced descriptions from Syndetics:

Three young people exist in a strange world of their parents' devising in this bizarre drama from writer and director Yorgos Lanthimos. A father and mother (Christos Stergioglou and Michele Valley) live in a large house on the outskirts of town with their three children, whose ages range from mid-teens to early twenties. The children have never been allowed to leave the house (which is surrounded by a tall fence), and their knowledge of the outside world has been strictly controlled by their parents, who have chosen to teach them only what they believe is important and have deliberately confused or misled them in many other areas. The parents quite literally treat their children like animals, and the only contact the youngsters have with people outside their family is Christina (Anna Kalaitzidou), a woman who works with the father's business and comes by periodically to have sex with the eldest son (Christos Passalis). Christina makes the mistake of bringing a present for the two younger daughters (Aggeliki Papoulia and Mary Tsoni), and explains the custom is that they should give her something in return. This simple act sets off a chain reaction of events that has terrible consequences for everyone involved. Kynodontas (aka Dogtooth) was an official selection at the 2009 Cannes Film Festival. ~ Mark Deming, Rovi