[mancerayder]

I have bruxism myself... What's the link with sleep apnea exactly? The jaw's position pushing the tongue back?

[nanidin]

I’m not sure which way the arrow of causation points - one of the body’s reactions to stopping breathing while unconscious is to grind the jaw.

[rewgs]

That's correct. You stop breathing and respond by clenching your jaw, resulting in TMJ.