Force necessry to dislocate TMJ? Gross yet curious

[jk5177]

To people who need a break from their studying:

Okay, this is got to be the weirdest question I ever posted, and the weirdest question I've ever seen. Despite its uniqueness, I am curious of an answer though.

What is the force necessary to dislocate the right TMJ?

Would dislocating the left TMJ be simply the answer from the above question times two?

Furthermore, now this is the gross part, what would be the force necessary to completely dislocate the mandibles? (As in dislocating TMJ, and then torn apart the tissues)

(Eeeks! Sorry, I know this is gross but I saw this happening on the movie: The Grudge. So I'm curious if that is even doable)

By the way, please give answer in terms of Newtons.

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[jk5177]

I guess nobody decided to partake in this post of mine. Come on, you OMFS people out there!

 

[ItsGavinC]

From a technical standpoint, is dislocation different from displacement?

 

[tx oms]

How would I know how many Newtons it takes? Some people dislocate their mandible frequently due to the architecture of their fossae. Like other joints and interacial sex, if you do it once it much easier to do a second time. As for violently avulsing the mandible (ripping it off someone's face), which is what I assume the second part of your question is asking, that would take lots of force. I've got an F150 with tow strap if you're interested in an experiment.

 

[egpndoc]

To people who need a break from their studying:

Okay, this is got to be the weirdest question I ever posted, and the weirdest question I've ever seen. Despite its uniqueness, I am curious of an answer though.

What is the force necessary to dislocate the right TMJ?

Would dislocating the left TMJ be simply the answer from the above question times two?

Furthermore, now this is the gross part, what would be the force necessary to completely dislocate the mandibles? (As in dislocating TMJ, and then torn apart the tissues)

(Eeeks! Sorry, I know this is gross but I saw this happening on the movie: The Grudge. So I'm curious if that is even doable)

By the way, please give answer in terms of Newtons.

This is seriously the weirdest question I have ever seen on SDN, I dont see why it matters how many newtons it takes. And Im sure every person has a different threshold.

 

[DDS2BE]

Wow jk5177, that is the weirdest question I've ever seen on SDN. You should probably get a “Wearied Question Award” or WQA for short. Too bad I can’t help, but at least I’ve learned a new term “Temporo-Mandibular Joint” from your post.

That movie, The Grudge, is it worth seeing? Some people saying it scared the living **** out of them, just like “The Ring” when it came out.

 

[ItsGavinC]

Too bad I can’t help, but at least I’ve learned a new term “Temporo-Mandibular Joint” from your post.

Wow, dental school will be a real treat for you.

 

[jk5177]

Still no answer! Come on. Come on. Come on.

 

[comatose]

wow, what an incredibly weird question....

 

[grmaster1]

To people who need a break from their studying:

Okay, this is got to be the weirdest question I ever posted, and the weirdest question I've ever seen. Despite its uniqueness, I am curious of an answer though.

What is the force necessary to dislocate the right TMJ?

Would dislocating the left TMJ be simply the answer from the above question times two?

Furthermore, now this is the gross part, what would be the force necessary to completely dislocate the mandibles? (As in dislocating TMJ, and then torn apart the tissues)

(Eeeks! Sorry, I know this is gross but I saw this happening on the movie: The Grudge. So I'm curious if that is even doable)

By the way, please give answer in terms of Newtons.

Here you go,

Physics 101 (for kids):

Max ultimate strength of a human ligament is about 100000000 N/m(squared)

Let's say an average diameter of all ligaments in a TMJ (both sides) is 2 cm, for argument's sake...

F/A=100000000 N/m(squared)

A=pi x r(squared)

F=100000000 N/m(squared) x pi x (0.01 m)(squared)=31400 N

That's not even counting muscles (not big contributors anyway), nor blood vessels, nor nerves, nor skin (if you wanna go gross)--so, you'll need more than that...

And, that's a ****load of force... Maybe that F150 is not gonna do it, 5 Fix Or Repair Dailies together is more like it...

By the way, every time you open your mouth wide--you dislocate your TMJ.

 

[unk_fxn]

I reduced a mandibular dx a couple months ago on an ER rotation... the guy came in had a history of intentionally "popping" his jaw for some time, but had never had this before... it allegedly came out while he was laughing at something his friend had said earlier that day. Rotten luck for him I guess.

I am an averaged sized adult man, and not a strong or muscular person by any measure. I was able to reduce the jaw with a moderate amount of force. Most of the action I found to be helpful is a rotational movement downward on the posterior mandible from the wrists.

I would have no idea how to measure such a thing.

 

[unk_fxn]

Here you go,

Let's say an average diameter of all ligaments in a TMJ (both sides) is 2 cm, for argument's sake...

F/A=100000000 N/m(squared)

A=pi x r(squared)

F=100000000 N/m(squared) x pi x (0.01 m)(squared)=31400 N

Given than 1000 N = 1kN = 220.5 static pounds 31.4kN = 6923.7 pounds.

This can't be the case because there is no way a weakling such as myself could be capable of such feats.

 

[grmaster1]

Given than 1000 N = 1kN = 220.5 static pounds 31.4kN = 6923.7 pounds.

This can't be the case because there is no way a weakling such as myself could be capable of such feats.

First, it's 7059 pound-force if you wanna play the conversion game...

And, second, I really don't understand your concern--if you're capable of developing forces equal to a turbojet engine of a B-47 stratojet,

you need to be on World's strongest man and Ripley's Believe it or not...

 

[Literati81]

To people who need a break from their studying:

Okay, this is got to be the weirdest question I ever posted, and the weirdest question I've ever seen. Despite its uniqueness, I am curious of an answer though.

What is the force necessary to dislocate the right TMJ?

Would dislocating the left TMJ be simply the answer from the above question times two?

Furthermore, now this is the gross part, what would be the force necessary to completely dislocate the mandibles? (As in dislocating TMJ, and then torn apart the tissues)

(Eeeks! Sorry, I know this is gross but I saw this happening on the movie: The Grudge. So I'm curious if that is even doable)

By the way, please give answer in terms of Newtons.

The answer to this question varies with each patient. Some people are more prone to lock-jaw and can dislocate their jaw by yawning. Some have hypermobile ligaments that would render them more vulnerable to dislocation. Age and gender are also factors to consider. I read somewhere that the most optimal TMJ can withstand pressures up to 200 lbs, or (depending on if I'm doing my conversions correctly) approx. 890 N.

As for the force required for dislocating both TMJs--I don't think F=2 X(Significant Dislocation of Right) as dislocating one side would probably offset the equilibrium. So it would probably be more like F<< 2 X (Significant Dislocation of Right), with "dislocation" being interpreted as any minimal disturbance to the positioning of the mandibular condyle within the fossa.

As for dislocating the entire mandible and tearing apart the tissues ...that's something we can leave to science fiction/C-horror flicks.

 

[DDS2BE]

Hey, I was just thinking ... this cold be done in gross anatomy class this fall and don't forget to share your experience with the rest of us

 

[jk5177]

Sweet responses.

 

[bananaface]

The answer to this question varies with each patient. Some people are more prone to lock-jaw and can dislocate their jaw by yawning.

Yawning and sometimes eating! Both sides don't necessarily require the same force to dislocate. And it varies based on tension, fatigue, etc. I'm just pointing out that there is even more variability involved than yet mentioned.

 

[joel4sale]

I did dislocate a jaw long time ago doing a emergency pulpectomy. Extremely aprehensive patient......Not sure if I pop the jaw or she dislocated herself but not too much force was there. I told her to relax the the jaw while the NaOCl soak in the chamber only to find out she is in "Lock Jaw" position..

Easily pop it back in by place thumb buccal to molar area and other finger support to chin and "Roate" it down/foward....jaw will guid itself back in. Not too much force was used.


PS. She later told me it had happend to her many time in the past....first time for me though.

 

[jk5177]

I did dislocate a jaw long time ago doing a emergency pulpectomy. Extremely aprehensive patient......Not sure if I pop the jaw or she dislocated herself but not too much force was there. I told her to relax the the jaw while the NaOCl soak in the chamber only to find out she is in "Lock Jaw" position..

Easily pop it back in by place thumb buccal to molar area and other finger support to chin and "Roate" it down/foward....jaw will guid itself back in. Not too much force was used.


PS. She later told me it had happend to her many time in the past....first time for me though.

Whoa. That is scary.