This advice-column-style blog for SLPs was authored by Pam Marshalla from 2006 to 2015, the archives of which can be explored here. Use the extensive keywords list found in the right-hand column (on mobile: at the bottom of the page) to browse specific topics, or use the search feature to locate specific words or phrases throughout the entire blog.
The best way to determine if a client is clenching is to palpate the masseters.
Do this on yourself first to learn the feeling. Place your fingertips on your masseters and then clench. Do you feel the bulge?
Now do this with your client. If the jaw is clenching you will feel the muscle belly bulge. If it isn’t, then you won’t.