To assess orthodontic treatment need in the Italian child population using the R.O.M.A. (Risk Of Malocclusion Assessment) Index.Observational study (cross-sectional).The ROMA Index was used in examining a sample of 420 children (214 males and 206 females; mean age: 9.3 years), none of whom had previously undergone orthodontic treatment. This basic sample was large enough to become the object of an epidemiological study and to be analysed through inferential statistics. After calculating the prevalence of malocclusion on the basis of the degrees of orthodontic risk determined by the Index, we evaluated the distribution of the most frequent characteristics, signs and symptoms within each risk grade. The percentage of children in each risk category was then worked out, together with its 95% confidence interval, in order to verify whether our results could be generalised to the reference population. Significantly, 50% of the examined children were classified as 'at moderate risk', as defined by grade 3 of the Index (non-severe alterations in dental and/or skeletal relationships, but tending to persist and often worsen with growth). Equally remarkably, a further 36% fell within grade 4 of the Index ('great risk'), presenting major craniofacial skeletal malformations and alterations of the occlusion, often in association with systemic or growth disorders likely to worsen the prognosis. Thus, since patients at moderate or great risk amounted to 86% of the basic sample, it appears that our estimate can be generalised to the reference population of Italian pre-adolescent children.The study showed a high percentage of children at moderate or great risk (86%), and that this estimate can be generalised to the reference population of Italian pre-adolescent children. These findings should be taken into great account in devising strategies to improve patient service quality, whether in public or private settings, and also in planning preventive measures and interventions.