A study on computer-aided mandibular-advancing system for obstructive sleep apnea

Objectives: To develop a computer aided mandibular repositioning system (CAMRS) for efficacy prediction of oral appliance in patients with obstructive sleep apnea (OSA) and investigate its pilot using in mandibular repositioning combined with polysomnography in OSA patients. Methods: During sleep the mandible could be repositioned through CAMRS mainly consisting of a step motor and a screw that was remotedly controlled by a computer. This system could work synchronizedly with polysomnographic device. 14 OSA patients diagnosed by initial polysomnographic monitoring were recruited. With CAMRS, six protrusively mandibibular positions(0, 2, 4, 6 ,8mm and maximum comfortable protrusion) were titrated with polysomnography for every one hour. Results: Stable mandible positioning and little sleeping disturbance could be carried out. The diagnostic polysomnographic study showed no statistically significant difference(P>0.05)for each sleep index(AHI, AI, HI or ODI)among the continuously sleeping hours from 1 hour after sleep onset. Overall, those sleep indexes improved progressively along with mandibular advancement. Through mandibular titration, an individualized mandibular position could be acquired for each patient. And the extent of advancement is correlated with the severity of OSA(P=0.0048). Conclusions: CAMRS could reproductively and effectively position mandible with little disturbance to sleep. With mandible protrusion, sleep of OSA patients improved as a whole. Individual mandibular position should be obtained for OSA patient treated with oral appliance to gain good efficacy.