Prevalencia de hábitos bucales parafuncionales en ni？os de edad preescolar en Ciudad Nezahualcóyotl, Estado de México, 2009

background. a habit is any activity done regularly and unconsciously, which is acquired by experience. non-nutritive buccal habits are important because they can interfere with the development of dental occlusion. the aim of this study was to evaluate the prevalence of non-eating buccal habits in a group of preschool children. methods. an epidemiological, cross-sectional and descriptive study to evaluate the clinical signs of non-nutritive buccal habits was performed by one previously calibrated examiner (intra-examiner kappa = 0.95). a questionnaire was completed for 211 preschool children from the information obtained in two stages: 1) parents of the children completed a questionnaire, and 2) the clinical evaluation of the children was registered by the examiner. results. of the studied population, 68.2% showed at least one non-nutritive buccal habit. onychophagia was the habit with the highest prevalence. the relationship between age and prevalence of non-nutritive buccal habits was statistically significant, whereas gender was not statistically significant. conclusions. there was a high prevalence of non-nutritive buccal habits not associated with the age of the child.