Table 2. Comparison of results between experimental group and control group.

Region	Experimental group		Control group
	Before treatment	After 4-week treatment	Before treatment	After 4-week treatment
Anterior region	18.93 ± 6.75	20.73 ± 6.61**	22 ± 5.74	22.86 ± 5.36*
Posterior region	16.2 ± 4.69	18.47 ± 4.09**	17.29 ± 4.3	17.71 ± 4.36

The values are mean ± standard deviation. Unit: pressure

*p<0.05, **p<0.01 by paired t test between initial and final scores in the group