Her head turned at Mark's entry, and her absorbed look melted into a brief spontaneous smile.

"A polite smile or a forced one produce a different muscle pattern than does a spontaneous smile."

In spontaneous smiles, the cheeks move up and the muscles around the eyes tighten, making crow's feet.

Despite everything, Bonifay flashed a spontaneous smile of appreciation.

A kind word, an attempt to do something new for himself, a spontaneous smile, each was a priceless gift.

Webb stared at her mouth, enchanted by that tiny, spontaneous smile.

A spontaneous smile is smiling without consciously thinking about it.

The primary neurorrhaphy and free muscle transfer are the only options to restore a true spontaneous smile.

They stand and stare at each other, then both break into spontaneous smiles.

It seemed so much more real, as if a veil had been lifted, that it brought spontaneous smiles to several listeners' faces.