xblokegb: Hey guys (and gals).
Having read with interest the problems that some folks have with shall I say getting their mouths open wide (

), I'd like to offer some advice I was given when I developed TMJ dysfuntion 'cos of grinding my teeth at night (and that IS the truth).
Bearing in mind I'm no doctor or dentists, so go ahead at your own risk. I didn't do this to unlock my jaw.
This is something I did to ease the tension in my jaw, and to try and correct the problems I developed because of grinding.
Perhaps you'd want to ask a dentist if this could work for you in preventing further wide mouth jaw locking episodes (Plowboy and others take note and pass it on).
1. With a closed mouth get the afflicted to point the tip of their tongue to the palate behind the front teeth.
2. Open the mouth a little, and keeping the tip of the tongue on the palate, slowly pass it back toward the back of the mouth.
3. Continue to open the mouth until it is fully wide (or still comfortable) and have the tongue, still touching the roof of the mouth, at the furthest point back you can get it.
4. Hold for a slow count of 4, and slowly reverse the movements until the mouth is loosely closed.
NB. Gentle, comfortable motions are the key.
Watch your mouth in a mirror to get the movements right and note any sideways motions in your jaw as you open and close your mouth. If you've not seen a dentist or doctor after you notice this, maybe you should. It was a sign of tempero-mandibular joint dysfunction in me.
About 10 times, one after another was about right for me but then I had a diagnosed condition and this exercise was given to me by a dentist.
Hope this helps.
Happy Deep Throating!
Xblokegb