In my estimation, the director uses the family environment as a metaphor to portray the suffocating relationship between oppressors and the oppressed - people who indulge themselves in the will of others. The apparently good and super protective parents symbolize oppression and the couple's children, the oppressed, subservient, imposed desires, controlled through alienation, lies, fear, manipulation, and psychological and physical violence. The story of the dogtooth, which gives the title to the film, is just another way to cheat and try to delay the desire for child liberation. The theme isn't new in the world of cinema. I remember a scene of manipulation of subaltern people in the film Sauve qui Peut (la Vie), of 1979, of the filmmaker Jean-Luc Godard. Another work that deals with this subject with a more explicit and critical bias towards power, and the outcasts of politicians aligned to fascism is Salò o le 120 giornate di Sodoma (1975), by Pier Paolo Pasolini.