Mandibular advancement splint titration in obstructive sleep apnoea

Mandibular advancement splints (MAS) allowing self-adjustment may be better tolerated, but the optimum titration protocol needs systematic study. The aims of the study are to assess the effectiveness of a titratable MAS device in consecutive patients with body mass index (BMI) < 35 kg/m(2) and obstructive sleep apnoea [OSA, apnoea-hypopnoea index (AHI) 10-40/h] and compare two methods of adjustment [self-adjustment or adjustment after polysomnographic (PSG) feedback]. Twenty-eight patients (24 M, mean age 49 years, mean BMI 27.6 kg/m(2)) with symptomatic (Epworth Sleepiness score > 8/24, snoring, choking or poor sleep quality) OSA (mean AHI 25.7/h, range 10-46/h) had a MAS set at 70% maximal protrusion and were randomised to subjective self-adjustment for 6 weeks (n = 16) or objective adjustment (n = 12; fixed position for 3 weeks, then PSG based feedback at 3 weeks with self-adjustment instructions). Primary outcome variable (AHI) and OSA symptoms were compared by t tests and chi-squared tests at baseline and after 6 weeks. Resolution of apnoea was defined as AHI < 5/h; improvement was defined as AHI decreased by > 50% but still > 5/h. The groups had similar baseline demographics, OSA severity and occlusal type. MAS therapy improved or resolved OSA in 20 out of 28 (71%) and was reportedly used nightly by 91% of the objective group and 63% of the subjective group (p = 0.04). MAS were used all night by 75% of the objective group and 69% of the subjective group (p > 0.05). MAS adjustment following PSG feedback did not lower AHI further from 3 weeks (baseline 26.5 +/- 12.0/h, 3 weeks 15.3 +/- 13.5/h p = 0.01, 6 weeks 11.7 +/- 10.0/h, p = 0.11). The overall improvement was similar to that achieved with subjective adjustment (baseline AHI 25.4 +/- 7.4/h, 6 weeks 14.3 +/- 10.7/h, p = 0.0002). Symptomatic benefit was reported by both groups. In selected patients, titratable MAS improved or resolved OSA in the majority of patients and was well tolerated. PSG-based feedback at 3 weeks allowed objective confirmation of efficacy and increased device use but did not result in greater improvement in AHI or symptoms. Neither titration method was significantly superior for us to provide firm endorsement. However, we recommend a follow-up sleep study to confirm MAS efficacy.