Table 3.

Asymmetry (Left versus Right or 3 versus 6 o’clock) in sphincter measurements

	Right Side (9 o’clock) of Patient (mean ± SD)	Left Side (3 o’clock) of Patient (mean ± SD)	Mean Difference Paired T-Test (9 o’clock minus 3 o’clock or right minus left)	p-value
EA-US thickness in mm
Proximal IAS (N=62)	1.37 ± 0.74	1.42 ± 0.59	−0.06	0.34
Mid IAS (N=62)	1.47 ± 0.65	1.38 ± 0.69	+0.09	0.010
Distal IAS (N=63)	1.79 ± 0.61	1.68 ± 0.59	+0.12	<0.01
EAS (N=62)	3.04 ± 1.80	2.84 ± 1.53	+0.20	0.01
TL-US thickness in mm
Proximal IAS (N=421)	2.22 ± 0.65	2.17 ± 0.63	+0.04	0.01
Mid IAS (N=423)	2.36 ± 0.62	2.28 ± 0.62	+0.09	<0.01
Distal IAS (N=417)	2.37 ± 0.62	2.25 ± 0.61	+0.12	<0.01
EAS (N=420)	3.78 ± 1.70	3.66 ± 1.68	+0.12	<0.01
PVM thickness in mm
Translabial 2-D (N=404)	6.97 ± 1.61	7.23 ± 1.67	−0.27	<0.01
Translabial 3-D (N=411)	7.01 ± 1.75	7.25 ± 1.86	−0.25	<0.01
Endoanal (N=132)	7.45 ± 1.46	7.31 ± 1.36	+0.14	0.10