Cephalometric analyses and flow-volume loops in obstructive sleep apnea patients.

Fifteen patients with obstructive sleep apnea syndrome (OSAS) and 10 controls were studied. Polygraphic monitoring during sleep confirmed the presence or absence of OSAS. Ten OSAS patients and five controls had cephalometric analysis and 12 OSAS patients and five controls had a flow-volume loop study during wakefulness. Seven OSAS patients were submitted to both analyses. Flow-volume loops were unable to detect extrathoracic airway obstruction in six out of 12 OSAS patients. One control was found with positive results. Six out of seven subjects with positive flow-volume loops were overweight (greater than or equal to 30% ideal weight). Cephalograms were very useful in demonstrating mandibular deficiencies in OSAS patients. The length of the soft palate and the position of the hyoid bone, together with the measurement of the posterior airway space, are criteria of great interest in OSAS patients. Cephalometric analysis is recommended in all OSAS patients scheduled for surgical procedure. None of these tests, however, whether alone or in combination, is capable of identifying all cases of OSAS.