Oral appliance therapy was not associated with improvements in daytime sleepiness from baseline to 4-month follow-up when compared with the placebo device ; Epworth score > 10 : 53 % at baseline to 24 % at follow-up for the oral appliance group vs 54 % at baseline to 40 % at follow-up for the placebo device group , P = .11 ; median ( IQR ) for Karolinska score 7/wk : 10 ( 8 to 14 ) at baseline to 7 ( 4 to 9 ) at follow-up for the oral appliance group vs 12 ( 6 to 15 ) at baseline to 8 ( 5 to 12 ) at follow-up for the placebo device group , P = .11 ; mean between-group difference in OSLER test , -2.4 min ( 95 % CI , -6.3 to 1.4 ) .