. 2018 Jan 20;38(5):463–476. doi: 10.1093/asj/sjx238

Table 2.

Comparison of the Thickness and Cross-Sectional Area of the Facial Muscles Before and After Facial Muscle Exercise Using the Pao Device

Muscle	Side	Before	After	P
Muscle	Side	Mean ± SD	Mean ± SD	P
Levator labii superioris, cm	Right	0.126 ± 0.023	0.136 ± 0.026	0.006
Levator labii superioris, cm	Left	0.125 ± 0.019	0.128 ± 0.021	0.230
Orbicularis oris, cm	Right	0.227 ± 0.041	0.235 ± 0.041	0.183
Orbicularis oris, cm	Left	0.212 ± 0.042	0.228 ± 0.036	0.019
Zygomaticus major, cm²	Right	0.772 ± 0.058	0.822 ± 0.063	0.000
Zygomaticus major, cm²	Left	0.773 ± 0.052	0.802 ± 0.064	0.015
Digastric muscle, cm²	Right	0.750 ± 0.126	0.799 ± 0.130	0.003
Digastric muscle, cm²	Left	0.740 ± 0.123	0.797 ± 0.126	0.001

SD, standard deviation.