His jaw tightened before he closed the door back once again.

I saw his jaw tighten as if at a blow.

He saw the stricken look in her face, and his jaw tightened.

Looking at him, she saw the way his jaw tightened.

Chief Stark opened the door, and when he saw that it was me, his jaw tightened.

As his jaw tightened I began to regret pushing him.

His jaw tightened as if that was not what he wanted to hear.

The words were quiet enough, but the man's jaw tightened.

His jaw tightened, and he looked back to the fire.

Her jaw tightened, and it was with difficulty that she spoke.