Table 2.

Percentage of mouth opening in different body positions and sleep stages

	RD group	ND group	p value
Mouth opening in
Supine (%)	16.0 ± 19.1	28.2 ± 11.7	< 0.01
Side (%)	18.9 ± 17.9	28.1 ± 13.9	< 0.05
REM-supine (%)	19.6 ± 20.2	35.7 ± 17.7	< 0.01
NREM-supine (%)	16.4 ± 18.0	28.2 ± 10.9	< 0.01
REM-side (%)	24.2 ± 19.9	29.6 ± 19.9	NS
NREM-side (%)	17.5 ± 16.8	27.8 ± 16.1	< 0.05

p values mean a significant mouth opening difference between RD group and ND group; NS, no significance (p > 0.05).