The aim of the study was to evaluate the efficiency of cephalometry in orthodontic treatment planning in patients with teeth crowding and Angle Class I molars relation. Cephalometric parameters were analyzed in 70 patients that completed orthodontic treatment in «Orthodont» dental clinic (Samara). Cephalometric X-rays were taken at baseline examination and after treatment. In patients with crowding and Class I molars relationship treated with extraction of all four first premolars correlation between N-Se and mandibular and maxillary length was disturbed. These patients showed higher N-Se and reduced jaws length than patients with no extraction or extraction of 2 premolars. The observed increase of G angle with reduced mandibular length assumes compensatory changes of mandible position. These disproportions were aggravated by facial growth. In certain cases cephalometric assessment is inefficient for treatment strategy choice.