An epidemiological survey of 483 adolescents had bean carried out in Budapest and Debrecen to assess the prevalence of malocclusion. The authors used the WHO's questionnaire "Dentofacial anomalies". Normocclusion was seen in 52.8% adolescents, Angle Class I. malocclusion in 23.2% and 25.9% had Angles Class II/1. Spacing of the upper segments was observed in 10.4%, while spacing of the lower segments was seen in 2.9%. Crowding of these segments occurred in 14.3%. Deep bite was found to occur in 26.1% of the patients. Statistically significant correlations were found between crowding and DMFT, DMFS mean values and frequency of dental plaque.