BACKGROUND The aim of this work was to perform a cephalometric analysis of the craniofacial parameters and natural head posture of mouth-breathers compared with control subjects, and to study the relationship between nose-breathing and the vertical dimension. METHODS The headfilms taken at start of treatment of 53 cases (28 girls, 25 boys) aged 9 to 30 who consulted the dento-facial orthopedic department of the Ibn Rochd Casablanca dental consultation and treatment center were studied. RESULTS Among the mouth-breathers, we noted mandibular retrusion (SNB) in association with posterior rotation and more pronounced tilt of the mandibular plane (PP-MP) compared with the controls (P<0.05), a disproportionate increase in anterior face height and a lessening of posterior face height (hyperdivergence). These increases in anterior face height are often associated with retrognathism (and open bite). CONCLUSIONS Our study has shown that there are cephalometric differences between mouth-breathers and nose-breathers. There are several studies in the literature with results that support ours. Collaboration between the pediatric dentist, the orthodontist and the ENT specialist is important so as to establish an early diagnosis of mouth-breathing in children and initiate appropriate treatment to recreate the best conditions for harmonious development.