Totally!! They should be careful of TMJ, especially if they are stressed!
[quote]Health Tip: While Chewing Gum May Relieve Stress ...
(HealthDay News) -- While chewing gum may help you feel better when you're stressed, don't overdo it, advises the University of Texas Southwestern Medical Center at Dallas.
When you're stressed, you may be prone to chewing more vigorously, which can strain your jaw.
Chewing too hard can cause fatigue and soreness in the jaw. It can also trigger a condition called TMJ, affecting the temporomandibular joint. The condition can causes pain in the head and the neck, and difficulty in opening and closing the jaw.
If you have any of these symptoms, give your jaw a rest and stop chewing gum for a few days. If symptoms don't subside, see a doctor.
-- Diana Kohnle[/quote]
http://www.medicinenet.com/script/main/art.asp?articlekey=83423