[Magnetic resonance imaging in dental appliance treatment of obstructive sleep apnea syndrome].

OBJECTIVE

To investigate the upper airway changes after wearing dental appliance in obstructive sleep apnea syndrome(OSAS).

METHODS

The research included 11 aged OSAS patients and 11 matched controls. Through dental appliance therapy the OSAS was proved by polysomnography to have ideal treatment results (AHI had decreased from 44.6 +/- 22.5 per hour to 7.53 +/- 6.44 per hour). Magnetic resonance imaging (MRI) had been performed before and after wearing dental appliance. The MRI images of upper airway after wearing dental appliance were compared with those of without wearing, and even with those of the controls.

RESULTS

After wearing dental appliance the size of upper airway increased greatly, from 12.27 ml +/- 4.13 ml to 13.93 ml +/- 4.58 ml(P < 0.01), While the size of oropharynx was increased from 5.55 ml +/- 2.10 ml to 6.88 ml +/- 2.26 ml (P < 0.001). There was still remained significant difference at nasopharynx, soft palate and tongue compared with the matched controls.

CONCLUSION

Dental appliance worked with the effect of enlarging upper airway. The abnormal airway morphology can not be changed completely by dental appliance treatment. MRI technique, especially the 3-D reconstruction model of upper airway, is an effective and special method in OSAS research.