Table 2. Ratio of subjects with a high risk of TMD between the instrument and control groups.

	Total	Instrument group	Control group	P value
N	138	72	66
Age: y (SD)	21.0(2.2)	20.0(1.1)	22.0(2.6)	< 0.001*a
Women (%)	87(63.0)	42(58.3)	45(68.2)	0.231b
High risk of TMD (%)	35(25.4)	21(29.2)	14(21.2)	0.283b

TMD, temporomandibular disorders; a, t test; b, chi-squared test; * P < 0.05