1.   His jaw clenched and unclenched as he listened to the speech.

2.   He paused, and she saw his jaw clench as he gave a cynical smile.

3.   His jaw clenched before he could stop it.

4.   As the lethal chemicals were pumped into his body, his jaw clenched but his breathing continued, then slowed.

5.   Even on the inside, jaws are clenching.

6.   Jaws clenched as if aching to fight.

7.   The study compared their brain activity with jaws relaxed and jaws clenched, and found that made a difference in the auditory cortex.

8.   Their jaws clenched, several stand rigidly and stare across the military demarcation line.