"Breathing in, I feel calm. Breathing out, I feel at ease. I am not struggling anymore. Calm/ease." And then, "Breathing in, I smile. Breathing out, I release all my worries and anxieties. Smile/release." We are able to smile to ourselves and release all our worries. There are more than three hundred muscles in our face, and when we know how to breath in and smile, these muscles can relax. This is "mouth yoga." We smile and we are able to release all of our feelings and emotions.

— Thich Nhat Hanh in The Heart of Buddha's Teaching