[Evaluation of effective jaw position and body posture for oral appliance of patients with obstructive sleep apnea syndrome].

PURPOSE

The aim of this study was to evaluate whether substantial airflow changes occur by changing both jaw position and body posture in normal subjects and patients with obstructive sleep apnea syndrome (OSAS).

METHODS

Fifteen normal controls (9 males and 6 females) and 15 male OSAS patients participated in this study. For all subjects their maximum forced inspiratory flow (FIF(25-75)) curve was measured in seven positions as follows: a) 0% jaw forward-upright position, b) 0% jaw forward-supine position, c) 50% jaw forward-supine position, d) 75% jaw forward-supine position, e) 0% jaw forward-lateral position, f) 50% jaw forward-lateral position, and g) 75% jaw forward-lateral position.

RESULTS

Although FIF(25-75) was increased by changing the body posture from supine to lateral in normal subjects, it was not increased by increasing the jaw forward position of them. On the other hand, the more forward the jaw position, the more FIF(25-75) increased in OSAS patients. However, it was not increased by changing the body posture of them. There were no significant differences between the 50% forward and 75% forward jaw positions in both groups.

CONCLUSIONS

In normal subjects, change of jaw position was more effective than that of body posture for FIF(25-75). However, in OSAS patients, change of body posture was more effective than that of jaw position for FIF(25-75). It was suggested that the treatment effect in the 50% forward position was similar to that in the 75% forward position.