MANDIBULAR ADVANCEMENT WITH DENTAL APPLIANCES IN OBSTRUCTIVE SLEEP-APNEA

The purpose of this study was to compare the effects of a modified Her bst appliance (mHA) and a muscle relaxation appliance (MR) on nocturna l breathing and body movement activity in patients with obstructive sl eep apnoea syndrome (OSAS). To increase the airway space posterior to the tongue base without severely affecting the craniomandibular joint, the mHA was adjusted to anchor the mandible at 50% of maximum protrus ion. MR producing an occlusal coverage but no protrusion served as a c ontrol appliance. All-night static charge-sensitive bed (SCSB) and fin ger oximeter recordings were done to six male patients in three condit ions: first without dental device and then with mHA and with MR, in a random order, after a 2 month period of habituation. The oxyhaemoglobi n desaturation events were 44.7h-1 of recording observed during the co ntrol night, 29.6h-1 with mHA (P = 0.087). The frequency of body movem ents decreased from 34.9 to 20.4h-1 (P = 0.0079), respectively. MR had no significant effects either on the frequency of the desaturation ev ents or the frequency of body movements, but the increased respiratory resistance breathing, indicating presence of partial upper airway obs truction, was reduced from 14.3 to 6.9% of the time in bed (P = 0.022) . We conclude that 50% protrusion chosen for these experiments, produc ed with a mHA, brought about some alleviation of upper airway obstruct ion in our preselected patients, but did not lead to sufficient contro l of apnoea. The reduction of partial upper airway obstruction induced with a MR warrants further studies in a larger patient population.