The study of periodontium endurance to horizontal loading at the patients 13-18 years with transversal incisor occlusion is carried out and 6 groups of the patients are allocated depending on a kind of jaws interincisor line displacement with a the median line of the face. On the basis of the received data the features of parameters of periodontium endurance of permanent teeth to horizontal loading are determined depending on a kind of interincisor line displacement.