Hi Everyone and welcome back to my YouTube channel! My name is Priya Mistry and I'm a General
Dentist whose practice is focused solely on taking care of those with TMJ Disorders. Today's video is
about the jaw locking closed or as we typically call it in our office a "closed lock", so that's
how I'll be referring to it throughout the video. In this condition, the jaw can barely open more
than one or two finger widths and there's a lot of pain associated with the side that is locked.
So for any General Dentist that might be watching or Endodontists,
Oral Surgeons, whoever may be watching.. we've all had patients come into our office
with a closed lock, and I practiced general dentistry for 11 years before
starting my TMJ practice with [me mentor] Dr. Parker. And in those 11 years,
I probably had about three to five patients a year or so come in with their jaw locked closed,
and I didn't know how to recognize it. I didn't know how to diagnose it, I didn't know how to
treat it and so oftentimes, I was just sort of left wondering what I can do for these people.
So I'm hoping hoping that this video can give you guys some clarification in your own practices so
that you're able to help more patients! That is always the ultimate goal! So in this video,
we will be quickly reviewing the anatomy of the joint - because it's important to have
an understanding of that - before we go on to talk about the five main signs and symptoms of a closed
lock, and how those signs and symptoms relate to what's happening within the joint itself.
The Temporomandibular Joint - or the jaw joint - has two bony parts to it. In between the two bony
parts, there sits a little pad of tissue made out of cartilage and it is called the Articular Disc.
Below this pad of tissue is the little bony knob that our mandible - our jaw bone - ends on,
and that's called the Condyle. The Condyle and the Disc should always be with each other, so if
you think of the Disc like a hoodie hanging out on the Condyle, they should always be together in all
the movements of the jaw. On top of that Disc, is the Temporal bone - which is a skull bone.
This bone has two parts to it that are relevant to the joint, and one is a little caved in
portion called the Fossa and the other is a bony hump called the Articular Eminence.
In front of the Disc is a muscle called the Lateral Pterygoid muscle. This muscle is one that
I call "the Troublemaker", and the reason I call it that is because this muscle can cause a lot of
pain - and I'll circle back around to that. Behind the Disc is some tissue that's highly innervated.
All that means is this tissue has a ton of nerves; it is nervy tissue and it is called
Retrodiscal Tissue - retro=behind, disc= discal. Retrodiscal Tissue; so that is the tissue that's
directly behind the disc. One last structure to be aware of that's not in this diagram here
is called the Discomalleolar Ligament. This ligament actually connects the Disc and and the
capsule of the joint to the Malleus, which is a bone in the middle ear. When the jaw goes to open,
the normal movement is that the condyle actually rotates in the fossa with the Disc on top of it,
and slides down the Articular Eminence, stopping when the Articular Eminence ends. It shouldn't go
beyond it, and in that whole movement the Disc stays on top of the Condyle, so if it's coming
on and off the Condyle, that's not a good thing. That's clicking and popping; the disc
should be on the condyle and that's sort of the crux to the closed lock situation.
So now that we've reviewed the anatomy of the joint, let's move on to the five main signs and
symptoms of a closed lock. So I'll list them off, and then I'll go back through each one of them
and explain exactly what's going on in the joint in relation to that sign or symptom.
The first one is that there is usually a period - whether it be days, weeks, months, years - of
clicking or popping in the joint that is going to have [before] the actual incident where it locks.
The second is the actual locking incident itself. What happens here is patients notice
they're barely able to open their mouths more than one or two finger widths, and that clicking
and popping noise is gone. Third is that there is immense pain associated with this condition.
Fourth is that the jaw or mandible actually tracks or deviates to the side that is locked.
And fifth is that patients will say that their bite feels off; their teeth aren't lining up
the way they used to. So now let's go back to number one and explain how it relates to
what's happening in the joint. So the clicking and the popping that's sort of leading up to
the locking incident; what that's telling us is that that little Disc of tissue is actually
coming in and out of alignment. It is not staying on top of the Condyle where we want it to stay,
so it's being a bad boy. It's getting out of alignment going where it's not supposed to go.
So we already know there's a problem within the joint leading up to the locking incident. Will all
joints that click and pop and snick and make noises eventually lock? No. Will some? Yes,
and it is impossible to predict whose joints are going to lock and who's or not, so
if there's popping or clicking in your joint it's probably better to just get it taken care of,
especially if it's painful. And by taken care of, I mean seeing a specialist for that. The
second symptom is the actual locking incident itself. So what happens here in the joint,
is that the Disc - instead of coming in and out of alignment - it actually gets completely out
of alignment. It gets dislocated or displaced, and where it goes is in front of the condyle.
So it moves forward and a little bit in, but essentially it serves as a barrier to opening.
So the condyles can still rotate, but when they go to slide down the articular eminence the Disc is
blocking one side so it really limits the opening, essentially. So the disc starts serving as a
barrier to opening instead of helping and serving as a cushion or a shock absorber for the joint.
Third is immense pain associated with this condition,
so what tissue is behind the disc? So if the disc moves forward what replaces it to serve
as something between the bony components of the joint? That tissue that's very, nervy - that
Retrodiscal Tissue that has tons of nerves in it, instead of being where it's supposed to be, is now
between the bony components of the joint and it's being compressed. And that causes a lot of pain,
and these patients especially notice this when they go to eat tougher to chew foods: bagels,
steak, beef jerky. And so they start to notice - "hey, this does not feel good so we're gonna
stick with a soft diet!". So a lot of these people will come in and they're already on a soft diet
because they just can't chew anything too hard; it just hurts too much. Another reason there's pain
is that that Lateral Pterygoid muscle - its job is to guard and support and protect the Disc - and
when the Disc comes out of alignment, that muscle freaks out.. for lack of a better word. It goes
into spasm; it becomes dysfunctional and when that muscle is dysfunctional, it can wreak havoc
which is why we call it "the Troublemaker". It can cause headaches, jaw pain, tooth pain,
pain behind the eye. I mean, it can really work you over once that becomes dysfunctional. And the
third reason this condition is painful is because of the Discomalleolar Ligament, so that ligament
that connects the Disc and the capsule to the Malleus bone in the middle ear. That ligament, if
it's stretched or strained, it can cause lancing, really kind of jarring pains in the in the ear;
and so these people are just so uncomfortable and in so much pain by the time they come to see us.
Fourth is that the jaw actually tracks or deviates to the side that's dislocated. So if you imagine
that this right side here is dislocated and this left side is okay the first movement
of the condyle is rotation and then it slides down the articular eminence. So this side is blocked
by the disc that's dislocated and this side can keep sliding, so you can imagine the whole jaw
will deviate when the patient goes to open the little bit that they can.
And fifth is that the bite does not line up anymore. So the way to explain this
is if you think of our two joints and our teeth coming together like cogs on a gear;
if you think of those three as a tripod - what happens when you cut one leg off a tripod? The
whole system goes out of balance; and so same thing. If the disc becomes dislocated,
this whole system goes out of balance and the jaw is actually in a slightly different position - so
like a hair of a millimeter, maybe, but that's enough to throw the bite off, because the jaw
bone carries all of our lower teeth and if it shifts in position a little it's not going to
line up against our upper teeth the same way. So these patients will notice that their bite feels
off or sometimes they won't notice it until you question them. So these are the five main signs
and symptoms that we should be looking for as Dentists, as Endodontists, as Oral Surgeons,
Periodontists, whatever it may be. It would be great if we could all recognize this because
the first place people go with these symptoms is their Dentist. We are not taught this in dental
school so it is not a crime of commission; it's more a crime of omission. We're just not taught
it - so you don't know what you don't know! And I just want to get all this knowledge out there
so that we can all better serve our patients. So the next video will be about how we treat
this condition in our office with a very high rate of success. What you General Dentists can
do to get your patients more comfortable, and which patients this occurs most commonly in,
and why.. so stay tuned for Part Two. I'm looking forward to seeing all of you soon! If you liked
what you heard, click "Like" and SUBSCRIBE to my channel, please. If you have any questions,
please ask them in the comments section. I'm so happy to answer them! Thank you guys so much!