Cephalometric analysis in patients with obstructive sleep apnoea syndrome: II. Soft tissue morphology.

Oropharyngeal soft tissue profiles were studied by cephalometric analysis in 25 patients with obstructive sleep apnoea syndrome (OSAS) and 10 controls. The length of the soft palate was significantly higher in patients (48.0 +/- 4.3 mm. (mean +/- SD) than in controls (35.3 +/- 4.6 mm.) (p less than 0.001), as was the distance of close contact between the tongue and the soft palate (23 +/- 12 mm. and 10 +/- 8 mm., respectively) (p less than 0.01). The area of the soft palate, measured in the sagittal plane, was 4.85 +/- 0.80 cm.2 and 2.88 +/- 0.62 in the patient and the control group, occupying 39 +/- 8 per cent and 21 +/- 5 per cent of the pharyngeal area (p less than 0.001). The lower outline of the tongue, represented by the line between vallecula (V) and the hyoid bone (AH) was more inferiorly positioned in patients, apparently giving the tongue a more upright position with more of the tongue tissue at the hypopharyngeal level than found in normals. The pharyngeal airway space had significantly reduced anteroposterior dimensions both at the nasopharyngeal and velopharyngeal level (P less than 0.001) as well as the hypopharyngeal level (p less than 0.05). Cephalometric analysis is highly recommended as a valuable tool in the presurgical evaluation of OSAS patients.