Kumar, you have a bony problem

I have been going to a 'new' dentist (new for me, that is) since about a week, about my dental problems, obviously. Today, after a sitting of root canal treatment, the doc cemented my tooth, and asked me to bite, so that the cement settles down in proper shape. Now, you should let loose the horses of your imagination, not too loose..just..get them running. Think of me sitting, in an almost sleeping posture, in that comfortable chair, which is made not so comfortable by those 2-3 arms of the chair which have me covered from all sides, leaving just the front(now top) part free, and the dentist was only too happy to oblige. Now, he was holding my lower jaw from both sides, and said
doc : "bite"
[ i tried to bite some imaginary stuff in my mouth ]
doc : "open your mouth wide and bite again"
[ i tried to bite some very big imaginary stuff in my mouth, opening my mouth as wide as one possibly can, when his jaws are held from both sides ]
doc : "again"
[ - ditto - ]
doc : "ok"
After some other finishing acts of the treatment, we changed to normal chairs meant for humans to sit in normal posture.
doc : "Kumar, you have a bony problem."
me : "?"
doc : "did your previous dentist mention that?"
[ me thinks, hey doc, when i dont know what you are talking about, how can i say yes or no? but decided to say no, as it looked safer to degrade the prev dentist for not diagnosing some unknown prob ]
me : "no..."
me : "but what exactly is it?"
doc : "hmm..let me explain it to you"
Now, the doc picked up a book and a pen and drew a side view of the human skull.
doc : "you see, the only moving portion in the human skull is the lower jaw, and it is attached to the skull by a ball and socket mechanism, like this"
[ the doc made some animations using his hands and fingers to help me understand ]
doc : "so, you see, when you open your mouth very wide, in your case, the ball slips out of the socket, and when you close your mouth, the attached muscles, pull it back in"
me : [shocked, scared..mouth wide open ]
doc : "Its not a problem right now. But you have to be carefull when you play. Sometimes, when people fall, they fall with their mouth open"
me : "okay"
doc : "If you happen to fall like that, then there is a chance that your jaw bone may come out of the socket and not go back in"
me : [confused, should i be scared? or should be laughing at my imagination of my mouth being stuck open? ]
doc :"If that happens, please see a dentist, or your regular physician. Dont allow anyone else to do any other thing, just go see the doctor"
me : [ more scared, more funnier imagination (walking in road with my mouth open, looking for a dentist), more confused, finally i guess i did both, gave a scared laughter] he..he..
doc : "If you cannot find a dentist or a doctor, pad your hands well, put your fingers in your mouth, hold your lower jaw by the sides of your teeth, by the sides, remember, because when it snaps back, it snaps back with a force, you may bite off your fingers otherwise"
me : ..
doc : "and push your jaw back into its socket..like this"
me : [ shocked, feeling incredulous about the whole thing, esp, the 'pushing it back in' part ] ..
me : "you mean, I can do that?"
doc : [ ignoring my shocked look ] "ya, otherwise get some other person to do it for you, but remember, from the sides, and fingers well paded"
The doc continued, obviously enjoying the act.
doc: "It may worsen with age, as the muscles supporting the mechanism loosen up. In your old age, things may turn so bad that, you yawn and your mouth is stuck open"
Now i could not control my laughter, imagine old me, sitting on some chair and yawning a yawn which doesnt let my mouth close.
doc : "but dont worry, by then, you would have learnt how to put it back in its place, you would be used to it!!"
me : [ speechless ]

So, that my friends, is my bony problem. An explanation of this to my friends here gave birth to many new ideas (like asking a stranger to give me a strong upper cut punch, and thanking him later) but I am bored of typing. So will end it here.