Table 3. The measured variables of hard tissues in PE group and control group(mm).

	Control(n = 30)		PE(n = 30)				P
			T1		T2
Variables	Mean	SD	Mean	SD	Mean	SD	T1&T2	T2&control
U3-U3	32.84	3.61	32.11	3.20	34.51	3.13	.000	.002
UⅤ-UⅤ	44.12	1.98	43.41	2.14	45.66	2.33	.000	.012
U6-U6	47.91	2.36	47.15	2.54	49.40	2.81	.000	.004
AL	29.11	2.12	28.86	2.84	31.41	3.21	.000	.001
C3-H	29.13	3.28	29.02	2.90	28.09	3.24	.020	.017
C3Me-H	2.89	1.59	2.52	1.64	3.31	2.26	.041	.043