Medical psychology is the branch of medicine which studies man as a subject and not only as an object: it takes as such interest in meanings. Any intervention in odonto-stomatology such as in any medical discipline can be considered besides from a technical, mechanical or lesional aspect from a psychological point of view. The purpose of this article is to draw the attention to the importance of the relationship between dentists and patients (father, mother and sexual roles of the practitioner) on the one hand and the psychological meanings of the oral cavity) nutrition, caption, agressivity, seduction) on the other, which are capable of influencing the results of certain dental treatments.