His jaw worked several times before any sound came out.

The boy's jaw worked, but his eyes never left the highway ahead.

Ann's jaw worked for a moment until the words finally came.

His jaw worked for a moment, as though he were trying to force it to function.

His jaw worked as though he would speak, but no sound came forth.

His jaws worked on the last of whatever he'd found in the nest.

Her jaws worked and a harsh sound came out of them.

The commander's jaws worked, but, at first, he did not know what to say.

For a moment, she watched his mouth and jaw work the stem.

His jaw worked just like Jeffrey's did when he was angry.