Cephalometric study of posterior airway space in patients affected by Class II occlusion and treated with orthognathic surgery.

The posterior airway space (PAS) is delimited by hard and soft tissues with anomalies that may produce alterations in volume. In patients with severe hypoplasia of the middle and lower third of the face, a decrease in volume of the PAS is present, producing a polysyndromic condition that ranges from snoring to obstructive sleep apnea syndrome (OSAS). The aim of this report is to define PAS variations via a cephalometric study in patients affected by class II occlusion and treated with orthognathic surgery. The authors studied 44 patients affected by class II occlusion who underwent surgery to correct the maxillomandibular malformation. The patient cohort was classified according to the type of surgery performed: Le Fort I osteotomy with or without a sagittal split osteotomy. To evaluate PAS variation, cephalometric analyses were performed by pre- and postoperative lateral teleradiography. This study showed an increase in PAS volume, especially at the hypopharynx and the lower part of the oropharynx, when the sagittal split osteotomy was performed and/or the maxilla was moved anteriorly and/or superiorly. A decrease of PAS can be seen in downward and/or backward maxillary movements. In conclusion, cephalometric studies of hard and soft tissues (such as tongue, pharynx, soft palate, etc.) should be performed in all patients affected by maxillomandibular malformation. This approach may provide data for the diagnosis of respiratory pathologies that vary from snoring to OSAS.