AIM: Our research aimed to find out whether it was possible to establish a correlation between instrumental polysomnographic variables in children with Sleep Disordered Breathing (SDB) and their clinical dentofacial records. MATERIALS AND METHODS: 197 children, 116 (59%) male and 81 (41%) female, age range 0 to 12 years, with a clinical history highly suggestive for SDB were enrolled. All patients underwent full-night Poly-Mesam examination and a specific clinical orthodontic evaluation. A comparison between polysomnographic variables and clinical orthodontic variables was made. RESULTS AND CONCLUSION: OSAS can not be diagnosed by the paediatric dentist only by performing a single clinical orthodontic examination of oral cavity, but a polysomnography is essential and, if this should point out any pathology referring to SDB, a cranial lateral cephalometry will then be required.