The boy turned, and the smile disappeared from his face.

Greg's smile disappeared as if it had never been there.

The smile disappeared from his face as he backed slowly away.

His smile disappeared, was replaced by a look of concern.

The smile disappeared as if he had not meant to say those words.

The easy smile disappeared, and in its place there was a look of anxiety.

The smile disappeared on seeing how serious the captain obviously was.

The smile on her face disappeared as she saw the small body he held.

Mark knew the smiles would disappear if he made it through the story.

His smile disappeared when he saw the strain in her face.