A mandibular advancement splint (MAS) may be an alternative treatment for snoring and obstructive sleep apnoea (OSA). However, there is little subjective or objective information concerning long-term effectiveness, compliance and side effects.A retrospective questionnaire was used to survey these issues plus patient satisfaction and maintenance requirements in 166 patients who could have worn a mandibular advancement splint for over a year.One-hundred and twenty-six (76%) subjects returned the questionnaire, (84 with OSA, 42 snorers), of whom 69 (55%) reported still using the splint regularly, 47 (37%) every night. The most common reported reasons for stopping use were discomfort (29/ 57; 52% of nonusers), and poor perceived efficacy (12 subjects). Users reported more daytime symptoms, and they and their partners were more likely to observe improvements with splint use. Side effects were reported by 49 subjects, more commonly in nonusers. Sixty-five of 67 current users and 23 of 41 nonusers reported less snoring with splint use (p~v0.001).Long-term mandibular advancement splint usage appeared less satisfactory than previously reported, however, splints were considered effective by 97% of current users and even by over half of those who had stopped use. Reasons for stopping use included side effects, social circumstances, dental treatment, as well as lack of perceived efficacy. Snoring and obstructive sleep apnoea (OSA) may result from collapse of the upper airway during sleep because of loss of muscle tone and anatomical factors. Bringing the mandible forward advances the tongue and thus enlarges the retroglossal airway, reducing the tendency to collapse [1]. Mandibular advancement devices are therefore being increasingly used as a treatment for snoring and as a possible alternative to nasal continuous positive airway pressure (CPAP) devices in OSA. Several randomized controlled trials of mandibular advancement splints (MAS) or nasal CPAP have shown splints to be effective in some patients and although they do not always lower the apnoea-hypopnoea index (AHI) as satisfactorily as CPAP, they are preferred by most patients in shortterm trials of 4 -12 weeks treatment [2 -4]. One study of long-term use of CPAP over a median follow up of 22 months, showed that 20% of 1,103 people stopped treatment after taking a machine home [5]. However, follow up with MAS has been limited to much smaller numbers and for a shorter time, with few data on longterm usage [6]. As splints are usually fitted because a patient is symptomatic or their partner complains about their snoring, continued use of the device will depend on the patient and their partner9s perceptions of symptomatic benefit and side effects. A retrospective questionnaire based study of factors affecting continued usage of mandibular advancement splints in 166 consecutive patients who had had a splint for at least one year was carried out. MethodsOne-hundred and sixty-six patients (140 males, 26 females) with sleep disordered breathing (111 OSA, 55 snorers)...

Measurement of cerebral tissue saturation during obstructive sleep apnoea (OSA) may provide additional information to conventional peripheral oxygen saturation.Thirteen subjects with OSA (mean apnoea/hypopnoea index 65.7±27.9) were monitored using full polysomnography and monitoring of near-infrared cerebral tissue oxygenation index (TOI). One-thousand and thirty-six apnoeas and hypopnoeas were analysed, in terms of duration, sleep stage, arterial oxygen saturation (Sa,O2) dip, minimumSa,O2, TOI dip and minimum TOI. Cerebral TOI is a measure of cerebral tissue saturation of haemoglobin with oxygen, calculated using near-infrared spatially resolved spectroscopy, which has been shown to have a high specificity for intracranial changes.Decreases in cerebral oxygenation were observed during apnoeas and hypopnoeas. Baseline TOI ranged from 50.1–73.0% and mean apnoea/hypopnoea related TOI dips ranged from 1.43–6.85%. MeanSa,O2dips varied from 3.8–21.7%. In regression analysis, factors significantly predicting the magnitude of the TOI dip wereSa,O2dip, minimumSa,O2, apnoea duration and rapid eye movement sleep stage. The effect of apnoea duration and sleep stage remained significant afterSa,O2was included in the regression equation.Near-infrared spectroscopy provides a noninvasive technique for monitoring cerebral tissue saturation during obstructive sleep apnoea.

Changes in directly measured cerebral tissue saturation and changes in arterial saturation and cerebral blood flow velocity (the 2 main factors affecting cerebral oxygenation) are associated with changes in cytochrome-oxidase oxidation state. The reduced cerebral oxygenation that occurs during obstructive sleep apnea is associated with changes in the intracellular redox state.