Posted by Smokey Stover on August 31, 2007
In Reply to: Tighten his jaw posted by Victoria S Dennis on August 30, 2007
: : : : : What does someone exactly do, if he "tightens his jaw"?
: : : : : The context is a lecture, the man giving the speech is quite tired of it already.
: : : : : "He tightened his jaw, coughed and drew himself up one last time"
: : : : It is an indication that he is determined, resolute.
: : : Incidentally, it's not a metaphor. It means he contracted the muscles around his jaw joints, like making a fist. ~rb
: : Unless he tightened his jaw in some peculiar way, the normal way to say it is, "He clenched his jaw." Or perhaps that's just the medico-dental way to say it, as in "Sleeping with yourjaw clenched is hard on your teeth."
: Mmh. In my book clenching one's jaw is a degree more intense than merely tightening it, and would indicate serious stress rather than mere resolve. Certainly to me "he tightened his jaw" seems a perfectly normal phrase. Is this perhaps a divergence between Leftpondian & Rightpondian usage? (VSD)
Probably not. If you can detect the tightening of someone else's jaw visually, it is because he is clenching his teeth or clenching his jaw (there's no difference). The masseter muscle is the clencher. You can probably feel this muscle in your own cheek, by opening and closing your mouth with your finger at the lower center of the cheek. Closing your mouth is not the same as tightening your jaw, but nearly so. Presumably "tightening" means closing your mouth and applying pressure with the masseter muscle, which is also what you do when you clench. You may feel there's a difference in usage, since "clench" is the verb used by dental and medical specialists when the action is listed among the various contributors to "TMJ," which is short for various disorders of the temporo-mandibular joint.
Although the jaw muscle is very strong, most of that strength is reserved for bringing the jaws together when there is something resistant between them, like a bone, a tough piece of meat, a "jawbreaker" (which is more likely to be a tooth-breaker), the dentist's finger.
Clench means to close tightly other body parts as well: fists and lips as well as teeth and jaws. It's a variant of clinch, and the two words sometimes overlap in meaning and usage.
You are old, said the youth,
And your jaws are too weak
For anything tougher than suet.
Yet you finished the goose,
With the bones and the beak.
Pray, how did you manage to do it?
In my youth, said his father,
I took to the law,
And argued each case with my wife.
And the muscular strength
Which it gave to my jaw
Has lasted the rest of my life.