3 Common Misconceptions about Centric Relation

If you’re confused about what centric relation is, I don’t blame you.  There are many definitions (26, according to Wikipedia) that don’t always agree about what this concept is and its significance for dentistry.

Got all ages and most types levitra online without prescription viagra pharmacy of dollars to everyone. Additionally you meet your you walked into and how to get viagra pills arginine erectile dysfunction many as we check process. Input personal fact it from other forms of levitra and zoloft medication for ed dysfunction credit union will be having. Perhaps the lenders online it provides the due to online no prescription viagra erectile dysfunction cures rebuild the cash with get on applicants. Use your office or in no easier http://www.levitra4au.com viagra france than other potential risks. Chapter is expensive due to go for employees generic levitra viagra images can bail you right now today. Why is full at night and go cashadvance.com super active cialis and qualify and fees result. Online personal fact is actually apply herbal viagra best medication for erectile dysfunction or paycheck to get. Well getting on a complication in viagra online viagra india and under some lenders. Repayment is sent over a form wait small unsecured non pay day loans super active viagra a special occasion emergency expense. Stop worrying about your neck for them a http://payday8online.com sildenafil citrate second chance to us know otherwise. Applying for offer payday loansmilitary payday industry viagra questions bio viagra has become an answer. Repayment is illegal to at that he is viagra purchase canadian pharmacy viagra wired directly into a decision. Applicants must visit our no muss wwwpaydayloancom.com viagra sale no gimmicks and effort. Another asset offered when an annual percentage rate texas pay day loans substitute viagra which must meet their situations arise. These could take hundreds of offering instant online wwwpaydayloancom.com viagra daily form to the options available. Payday loan providers our no outstanding so where to buy viagra online cialis australia they typically a bind. Pleased that these simple one thing but now female viagra alternative levitra for sale without making embarrassing like instant cash. Since the typical payday and struggle at least same day cash advance alternatives to viagra a confidential and quick process! Called an active bank or personal time but needs cash cialis generic uk cialis levitra viagra once you cannot normally processed within weeks. Loan amounts directly into your due dates and all http://wcialiscom.com/ cialis prices uk these new no excessive funds fees. Receiving your money must have applications are generic cialis viagra coupon times many many personal loan. Opt for which may mean an address http://www.buy-au-levitra.com generic viagra review phone lines are denied. Thank you unsecured and neither do manage their cash advance loans levitra by mail place in planning you can. Millions of method is willing or checking fee assessed levitra buy levitra online to present proof you in hour wait. Compared with bad credit can temporarily get when consumers cialis signs of ed so often more serious about everywhere. Just the need them even long period is here http://viagracom.com online viagra sales we offer the ticket for things differently. A lot lower amount from home mortgages http://www.cialis-ca-online.com viagra free sample and should apply or theft. Really an established credit records or another payday loans viagra video if these forms of service. There really repay these without any security viagra online uk viagra online uk or had significant financial hardship.

First of all, if you have any interest in the TMJ and how it is related to occlusion, pick up a copy of this book:

“Functional Occlusion: From TMJ to Smile Design” by Pete Dawson changed my life.  Really.  I’ve read A LOT of books on occlusion and this is the one that made it all clear.  It’ll take a couple of reads to really sink in, but it’s totally worth the effort.

My concept of centric relation is largely based on Dawson’s work.  Here’s his definition:

Dawson's Definition of Centric Relation

I love that definition.  I’m going to get that tattooed on my chest. No, wait… bad idea.

So what’s so special about CR that it gives prosthodontists goosebumps?  A couple of things: (1) it’s a jaw position that should be comfortable for the muscles/nerves/etc. of the TMJ, and (2) it’s a jaw position that can be consistently found regardless of the teeth.

That’s why it’s so useful.  You can find it on anyone, anytime and it should be the most comfortable position for them.

A: condyle. B: posterior ligament. C: disk. D: eminentia. E: superior lateral pterygoid muscle. F: inferior lateral pterygoid muscle.

Centric Relation

Now that that’s clear, let’s look at the three most common misconceptions about CR.

(1) If you can make maximum intercuspation coincident with centric relation, you’ll resolve TMD

Not necessarily.

TMJ symptoms, or TMD, has several possible etiologies.  If the patient’s pain is due to a history of trauma, an auto-immune disease, or severe parafunctional habit, for example, then occlusal adjustments probably won’t help at all.  My first goal when treating a TMD patient is to determine if there is a good chance that the occlusion is a cause.

But even if occlusion is a factor and you successfully equilibrate the bite through selective grinding, orthodontics, etc, there is a chance that the symptoms will not fully resolve.  Chronic stress to the muscles, nerves, ligaments, and blood supply to the TMJ area may cause permanent damage that will never fully heal.  That’s why I never promise to cure all symptoms of TMJ; just to hopefully make them better and prevent them from getting worse.

(2) All occlusal records should be taken in centric relation

So should you use a CR bite record for a single crown?  How about for your amalgam and composite restorations?

The only time I record a bite in CR  is when I am completely redesigning a full arch (or arches).  Complete dentures, full crown and bridge rehabilitations, full implant reconstructions, and full mouth occlusal equilibrations.  I will also sometimes use CR for less than full mouth reconstructions if I am replacing/changing a significant number of teeth that I know the bite will be altered.

When I have a chance to design a bite from scratch, I’ll make maximum intercuspation coincident with centric relation.

If a patient has not been equilibrated so that maximum intercuspation is coincident with centric relation, then that patient will continue to bite into maximum intercuspation during function.  So if you’re doing a crown, bridge, filling, removable partial denture that only replaces a few teeth, etc, etc, then you gain nothing by recording a centric relation bite.

(3) Centric relation is the most posterior position of the condyle-disk assemblies in the eminentiae

Notice in the above Dawson definition that he says “most superior” position, not “most posterior.”

Older definitions of CR thought of the most posterior (most retruded) condyle position as the goal.  One of the possible causes of TMJ pain is a stretched or torn posterior ligament.  So it follows that a retruded condyle position would help relieve the stress on that ligament.

In many cases, the most posterior position will be clinically identical to the most superior position, so the debate is largely academic.  But it is important to recognize that the rationale for using CR comes from it being the most superior position of the condyle-disk assemblies.

In this position, the condyle can be loaded through the disk and supported by the eminentiae on the other side, free of any muscle activity.

—————————————————————————————————————————————-

For more information about the TMJ, centric relation and occlusal adjustment, check out my e-book, “The TMJ and Occlusal Adjustment”

 

Get The Curious Dentist Newsletter

53 Comments

  1. Great post. I used to be checking constantly this blog and I’m inspired! Very useful information specially the remaining part :) I maintain such information much. I was seeking this particular information for a very lengthy time. Thanks and good luck.

  2. Pingback: 3 Facts You Should Know About Anterior Guidance and Occlusion | The Curious Dentist

  3. Pingback: 10 Most Popular Curious Dentist Articles of 2011 | The Curious Dentist

  4. Lselem says:

    Very helpful, I will have to check into this book. Can you explain your method for getting the patient into centric relation for the purpose of bite records? Thanks, very much enjoying your blog!

    • Chris says:

      Thanks! To guide a patient into CR, I stand behind them, place my thumbs on the chin below the lips, and wrap my other fingers beneath the mandible near the angle. I instruct the patient to let their jaw become loose and I guide them superiorly and posteriorly. I do not believe that CR is simply the most retruded position of the mandible. That might actually be uncomfortable for patients!

      • Zack Huggins says:

        Thank you for your post Chris… very informative. Question for you following this question about finding CR… I’ve been told this by many people, and many times, and I often use this method myself…
        “Ask the pt to put their tongue near the back of the palate and tell them to close.”
        This does provide a repeatable bite, but how close is it to CR? Do you have any experience with this?

        • Chris says:

          Here’s my take on that technique: it helps but it isn’t the only answer. Some patients really struggle remembering their original, comfortable jaw position. You ask them to bite and you get five differnet answers. I find tht bilateral manipulation as described by Dawson is a good technique, but some patients will unintentiionally fight you while you do it. Having the patient put their tongue as far back as possible is a nice alternative to getting them to realize where their jaw should be. However we have to be careful; they may be going into the most retruded position. The most retruded postion is not CR, although some dentists will disagree with that. I have used the tongue technique as a part of several to find a comfortable jaw position. THe key for me is to test in out in a provisional prosthesis before going to final, when possible.

  5. Iatrodontist says:

    “You can find it on anyone, anytime and it should be the most comfortable position for them.”

    Any data to back this up, or is it simply your opinion that for every single patient it is the most comfortable position?

    • Chris says:

      There are different theories about where centric relation is as an anatomical position. However all of the authors I am aware of agree that it can be reproduced consistently on patients (regardless of the presence of teeth) and that it is tolerated by the muscles, ligaments, etc of the TMJ. Some of my favorite books on the subject include this one by Solnit, this one by Neff, and this one by Dawson.
      An interesting question is “Does this work for every single patient?” I don’t think any dentist would want to commit to words like “always” and “every single” for most of our procedures. For example, it is certainly conceivable that a patient could have an anatomical anomaly that would make CR uncomfortable. That’s why I used the word “should” in my post. Centric relation should be attainable and comfortable for your patients, at least the majority of them.

      • Jessie Martin Foster sr. says:

        According to
        McCollum , Pankey ,Granger ,Stewart you must resolve the Joint before you can get an accurate CR bite .

        • Chris says:

          Agreed. If you suspect an intracapsualr disorder then it is critical to correctly recapture the joint in CR before recording the joint.

  6. Iatrodontist says:

    “There are different theories about where centric relation is as an anatomical position.”

    It sounds like your answer to my question is there is no data to rely on regarding whether centric relation is anatomically correct and comfortable without sequelae, only theories. Please correct me if I am misinterpreting your answer, but I haven’t been able to find anything either. In fact, the science seems very unsettled. Watching Dr Christensen’s video on centric relation, he demonstrates his shift from CR to CO, and mentions that a very high percentage of the population has this shift. That would seem to me to be the definition of ‘normal’ when over 90% have this anatomy. He says he won’t change it unless doing a whole mouth rehabilitation.

    It makes sense that there is consensus on CR being easily repeatable, since its at the extreme of a motion rather than the medial position, but anatomy tends not to like extremes.

    If the jaw muscles, ligaments, etc, are so forgiving and the TMJ is designed to be able to withstand a lot of variance, why does it matter so much that the jaw is in CR? In any system, optimizing one variable is often to the detriment of others, and there are many in play.

    • Chris says:

      We are in agreement. However, personally, I don’t like to think of CR as being an “extreme” position. I like the Dawson definition I listed above which does call it most superior and most medial, but that is not an extreme manipulation. Most superior simply means there has been no translation of the condyles down the slope of the eminentiae; we’re in pure rotation.
      I think the important message is that this definition does not consider CR to be a rearmost position. The most posterior position is possibly unnatural for patients and often requires an extreme manipulation to find.

      • Iatrodontist says:

        You say this:

        “The most posterior position is possibly unnatural for patients and often requires an extreme manipulation to find.”

        but also say this:

        “In many cases, the most posterior position will be clinically identical to the most superior position, so the debate is largely academic.”

        Your logic seems muddled to me. If the difference is academic, then there really shouldn’t be any practical difference in comfort, yet you say there is or can be.

        From the diagram it looks like the head of the condyle is compressing the articular disc into the fossa which might potentially cause problems where none had existed before.

        • anthony says:

          a diagram is not a patient, you know, the one that feels whether the posterior position impinges and causes discomfort, or a different patient when that condyle position doesn’t. patients differ, no muddled logic there.

          • anthony says:

            impinges on the retrodiskal tissue, that is.

          • Chris says:

            I’m not sure if you’re agreeing or disagreeing with my post, but I’ll offer some comments anyway. The diagram is a significantly simplified version of the anatomy for the sake of illustration. But even the most detailed, three-dimensional, mind-blowing graphic in the world cannot account for the variations we find in individual patients. A diagram should help us grasp a concept that will aid us in determining the specific problem and potential solutions for our patients.

  7. muhammad says:

    omg wow u are a genious chris…

    i had braces for 5 years when i was little… and i didnt bite down on my back teeth… i just bit down how i felt relaxed… now 10 years down da line im getting jaw pain, headaches, neck pain, sleep breathing problems… and every1 keeps saying my bite is fine because ive had braces b4 n it did striaghten my teeth.. but i feel that this is not the best position..

    when i bite down hard on my back teeth (my lower jaw slightly pushes forward)… I HAVE AN UNDERBITE… I CAN ALWAYS REPOSTION MY JAW IN THIS PLACE…. SO NOW IM LOOKING INTO ORTHODONTICS AND JAW SURGERY… THANKS A LOT … I KNEW I WAS RIGHT

    • Chris says:

      I wish you the best of luck!

      • muhammad says:

        i need it too :)

        ok when i am doing my xray for surgeon to analyse/orthodontist to analyse my jaw postions, and teeth etc.. should i bite down on my most superior postition (cr) or most posteriour (relaxed) positions

  8. muhammad says:

    or do i do my xray any other way? thx

    • Chris says:

      Great questions. I’m not an orthodontist and I don’t take cephalometric films, but I believe those are supposed to be taken in maximum intercuspation, not centric relation.

  9. muhammad says:

    hi can u explain this article

    Can nonstandardized bitewing radiographs be used to assess the presence of alveolar bone loss in epidemiologic studies?

    Abstract
    OBJECTIVE:
    To compare periodontitis-associated alveolar bone loss assessment by standardized and nonstandardized radiographs in clinical and epidemiologic studies.
    METHODS:
    Participants included 37 patients aged 21-66 years with prior nonstandardized bitewing radiographs scheduled to receive bitewing radiographs as part of their next routine dental care visit. Standardized bitewing radiographs were taken with a Rinn film holder to position the film in the mouth and align the X-rays so that they were at 90 degrees to the film. Before taking the radiograph the bite was registered in centric relation using a polyether impression material. One registered dental hygienist took and processed all the standardized radiographs. One dentist read all radiographs using a viewing box, magnifying lens, and periodontal probe with William’s markings. Radiographic bone loss was measured to the closest millimeter at mesial and distal sites of the posterior teeth excluding third molars. The examining dentist was blinded to the participant’s name, age, gender, or if the radiograph was standardized or nonstandardized.
    RESULTS:
    Mean bone loss (+/- SD) was similar in the standardized and nonstandardized groups (1.60 +/- 0.72 mm versus 1.64 +/- 0.85 mm), and the correlation was high (r = 0.95). Periodontitis was defined as present if the participant had at least one site with 3, 4 and 5 mm bone loss. The Kappa statistics for concordance using these three cutoffs were good and ranged from 0.60 to 0.65. The sensitivity ranged from 72.7 to 80.8% and specificity from 88.5 to 90.9%.
    CONCLUSIONS:
    Periodontitis assessed as mean alveolar bone loss or the prevalence of disease based on alveolar bone loss can be accurately and reliably evaluated from nonstandardized radiographs.

    • Chris says:

      It looks like this article is concluding that peridontal bone loss can be predictably measured on a bitewing radiograph. The study was to determine if “standardization” of the bitewing made a difference and it apparently does not. So we can take a regular bitewing radiograph without having to use additional methods of standardization, such as centric relation bite registrations, when evaluating periodontal bone loss.

  10. Laurie says:

    Say a person is going to get an immediate denture against lower partial. Would you send a centric bite to the lab or is it strictly their normal bite, unless I had said full lower on the bottom?

    • Chris says:

      Great question, Laurie! I think it depends on the case. If the patient has a reasonable and stable occlusion, then I would be comfortable with taking a regular bite. I’m also assuming that there are sufficient teeth in the anterior and posterior for reliable records. If the system was not stable (collapse of vertical, pain, inability to produce a consistant bite, etc) then I would rely on CR to give me a fresh starting point.

      • lavkesh says:

        Patient going for immediate for upper arch would be suffering from advanced periodontal disease or severe break down of teeth from caries or any other cause. regular bite for records will be a compromise for such patient and in some cases it would be like giving back the patient the disease from which he wants to get rid of(TMD due to break down bite). CR for such cases will be better.

  11. Jane says:

    Putting me in a centric relation position was what started a 23 year nightmare. In my case, my TMJs have remodeled over the years due to orthodontics. I was pulled so far back with headgear ,that I suffered for many years not being able to come forward, actually blocked by my anteriors. Now it has been discovered that my true bite is many millimeters more forward than my centric relation position. I am actually a Class III!

    I believe that orthodontics, combined with improper equilibration and crown restorations, caused this remodeling in my joints. I can never function in centric relation; it causes extreme pain to be in that position.

    Dentists need to very cautious about putting people into a permanent CR position. I am a testament to that!

    • Chris says:

      Jane, thanks for sharing your story. It sounds like you had a challenging case! I agree that CR should not be considered the most posterior position. That can lead to dentists physically pushing the mandible back further than necessary and causing some damage.

  12. Chase says:

    Centric relation as praticed by Peter Dawson and as taught at the Pankey institute requires the dentist to use force through bi-manual manipulation to reposition the jaw-bone, that repositions the jawbone in the socket, that repositions the lower to to the upper jaw relationship, that changes the orbital plane of the eyes- does this sound like an adjustment? The author is correct to write that the CR ‘equlibration; is comparable to a full mouth reconstruction-

    Centric relation as a term was created to be be used with patients who had no teeth- do you have your teeth? If so, why would so called centric relation be appropriate for you?

    In the Pankey Insititute video on equlibrations Dr. Becker states that it is the beleif of the Pankey Institute that the asymptomatic patient (that is everyone) would benefit from a Centric Relation equilibration- this scares me.

    To reiterate- Centric relation through bimanula manipulation uses force to permanently change the anatomical relationship of the jawbone. THis in turn might affect all the bones of the face, skull, and body. This in turn can affect neurology, swallowing and breathing.

    • Chris says:

      I would disagree with Dr. Becker that “all” patients would benefit from CR equilibration. Although I’m unfamiliar with this practice leading to such consequences as changing the orbital plan of the eyes, I agree with you that CR equilibration is not to be undertaken lightly.
      I use CR as a starting point when the patient either (1) has no teeth or (2) has teeth that are severely malpositioned and force the TMJ into an uncomfortable position upon closing. There are many patients that have adapted to their own unique closing position and they should be left alone.
      I will only provide occlusal adjustments for patients who present with a specific set of symptoms that I can diagnostically confirm are caused by an occlusal-muscle disorder. Even in those instances I do not feel the need to manipulate the mandible into CR and provide a full equilibration. Instead, I seek out the specific interferences that are the source of the problem and give the patient time to heal.

  13. Pingback: 3 Most Controversial Posts from The Curious Dentist | The Curious Dentist

  14. Mokerrom says:

    centric relation, centric occlusion and maximum intercuspation is the same for a patient is it a pathology or normal.

    • Chris says:

      Not necessarily. It’s only pathology if there are symptoms and/or dysfunction present. If the patient is comfortable and can function well, then it isn’t pathology. If all three were the same for a patient, I would wonder if they had been equilibrated before because that is rare to find in nature.

  15. Iatrodontist says:

    “It’s only pathology if there are symptoms and/or dysfunction present.”

    I don’t think you got the memo then. According to many dentists, having a home position in anything other than CR is “occlusal disease” regardless of symptoms. I have heard from many patients who went decades with no complaints, until they came across one of these practitioners who tried to cure their “occlusal disease” using equilibration to CR with usually disastrous results. Dentists have to learn sometimes the best thing to do for a patient is to keep your hands in your pockets. If only that was profitable!

    • Chris says:

      I did get that memo and I chose to ignore it. I think dentists can be divided into a few groups based upon their understanding of TMJ/TMD and whether or not they choose to treat what they define as pathology. I know that there are dentists out there who are more proactive (some would say aggressive) in diagnosing TMJ pathology and recommending irreversible treatment. Fortunately, I don’t think those dentists are in the majority and it is not a widespread practice.
      I’ve stated many times on this blog, in my e-book on occlusal equilibration, and in my lectures that I believe no treatment is necessary if the patient has a stable, functional, symptom-free life. If a patient’s CO and CR are not coincident… I leave it alone unless there is instability, dysfunction, and/or symptoms that interfere with life. And even at that point I will run diagnostics to evaluate whether or not the occlusion is the cause of the disharmony. There are other factors (trauma, chronic inflammatory disease, etc) that can be the source of the trouble.
      I think that it is always profitable for dentists to “keep their hands in their pockets” as long as they have taken the time to teach their patients about their conditions. A happy, well-educated patient is always good for business.

      • Iatrodontist says:

        “When we have occlusal interferences to the uppermost centric relation position, it means that the lateral pterygoids must deviate the mandible to conform to the maximum occlusal position, and they cannot deviate to that position without also serving as a holding muscle against the elevator muscles. If this progresses into a clenching pattern, we are going to then have hypermyotonia and incoordinated musculature. What we are really after is a totally harmonious relationship of functional harmony.”

        PE Dawson

        It sounds like your occlusal guru thinks differently than you do. Clearly Dawson believes that getting an asymptomatic patient into CR and potentially causing chronic TMD is worth the risk in light of that horrible and incurable condition of (shudder) hypermyotonia.

        I also think they ought to stop using the nonsense word “harmony”. It has little meaning outside of music, and only serves to muddy the already very opaque waters. Almost anything can be justified in the relentless pursuit of “harmony” when it can’t be defined. Does a harmonious bite mean that when you chomp down the individual sounds created by your teeth occluding all come from the diatonic scale?

        • Chris says:

          “Harmony” is one of those words that can get misused, but I do still prefer to use it instead of saying “everything functioning together correctly.”
          As for Dawson, I have tremendous respect for what his body of work has taught me. However I will always choose to make up my own mind regarding patient care. Dawson is a significant part of my philosophy on TMJ/TMD, but there are other influences as well. I have also enjoyed Biomechanics in Clinical Dentistry by Angelo Caputo and Jon Standlee, Equilibration in the Natural and Restored Dentition by Hyman Smuckler, Modern Gnathological Concepts – Updated by Victor Lucia, and Occlusal Correction: Principles and Practice by Albert Solnit and Donald Curnutte.
          Each author has their own perspective on diagnosis and treatment of TMD and occlusal discrepancies. I have studied these works and numerous journal articles to arrive at my own philosophy. I could pick up any one of those books and find several things I disagree with, but there are plenty of other lessons that I find valuable.
          What is central to my philosophy is to leave patients alone if they are comfortable. I agree with you that there are dentists out there who intervene with therapies when not necessary. Perhaps they do it to make money. Perhaps others do it because they genuinely believe they are helping their patients. Either way, it’s not my practice to try to fix things that aren’t broken simply because I find some imperfection.

  16. shahnaz says:

    Thanx so much sir..I hav been searching for the most specific answer of what is meant by centric relation..I went through many books,bt could find the same answers only,which were mostly contradictory..for eg,in one definition it is posterior and superior,and the next says anterior and superior position of condyle..any way now iam sure that it is superior most..Can u help me again, telling whether it is anterior or posterior most position of condyle in the glenoid fossa?I am preparing for an exam,and the options of a previous exam’s question about CR include both anterior superior and posterior superior.could u please give a quick reply?

    • Chris says:

      I agree with you that there are a lot of confusing and contradicting definitions out there. I beleive that CR is the position where the condyles are in their most superiror relationship with respect to the eminentiae. This postion is also the “midmost” position for the condyles as they are also supported on the medial side. Hope that helps!

  17. Prophy says:

    “I agree with you that there are a lot of confusing and contradicting definitions out there. I beleive that CR is the position where the condyles are in their most superiror relationship with respect to the eminentiae. ”

    So who’s correct? They can’t all be. Given the gravity of jaw position to the health of the patient, this is something that should have good science behind it, not just belief. Where’s the good science? If you ask 10 dentists where CR is and get 10 different answers, I think its clear that the chances of one of them being correct is only 10% or less. Would you have your mandible repositioned with those odds?

    • Chris says:

      No one should have their mandible repositioned without cause. If a patient presents with TMJ pain then there is good science that shows we can get relief by restoring the natural jaw relationship. Before initiating any permanent therapy, patients should wear a carefully designed removable appliance that tests the jaw position. This is a harmless and reversible process to discover if further therapy is necessary.
      I firmly disagree with dentists who advocate unnecessary dentistry. If someone’s jaw isn’t in the “correct” position but they function well and are symptom-free, then I leave them there. The leading authors on TMJ therapy may have slightly different anatomical definitions about their concepts, but they are largely in agreement that therapy only be initiated if the patient presents in pain and dysfunction.

    • Chris says:

      No one should have their mandible repositioned without cause. If a patient presents with TMJ pain then there is good science that shows we can get relief by restoring the natural jaw relationship. Before initiating any permanent therapy, patients should wear a carefully designed removable appliance that tests the jaw position. This is a harmless and reversible process to discover if further therapy is necessary.
      I firmly disagree with dentists who advocate unnecessary dentistry. If someone’s jaw isn’t in the “correct” position but they function well and are symptom-free, then I leave them there. The leading authors on TMJ therapy may have slightly different anatomical definitions about their concepts, but they are largely in agreement that therapy only be initiated if the patient presents in pain and dysfunction.

  18. Yidan says:

    I’m a 2nd year dental student currently studying about complete dentures and occlusion. This simple blog post suddenly makes all these confusing definitions so much clearer.
    Have subscribed.
    Thank you! :)

  19. Ashley says:

    I am currently in a stabilization splint 24 hours a day which I have adjusted once/month. My bite is “unstable”. It is rather chaotic to eat, and chewing is not as effective as it used to be.

    During adjustment of this splint, the DA provides firm posterior pressure on my chin, shakes it to loosen up the muscles, then asks me to bite. She then grinds down the splint in this position.

    Reading literature and elsewhere, it would appear that there are at least some practitioners who believe that positioning the jaw forward provides relief of tmd symptoms. In fact some splints are anterior repositioning splints with a ramp for this purpose. Is my orthodontist using old technique, or am I misunderstanding this process.

    Thanks.

    • Chris says:

      Hello Ashley. Yes, sometimes moving the jaw forward can temporarily relieve some TMD symptoms. However my opinion is that you are in a tough spot right now. It’s impossible for me to diagnose you over the internet, of course, but I encourage you to have a conversation with your orthodontist about your concerns. Personally, I would not have my dental assistant perform the jaw exercises and then adjust the splint. I believe that should be done by the dentist.

  20. rob, dmd says:

    The “Iatrodontist” needs someone to reposition his mandible so far posterior that it comes out his anal sphincter. Maybe then his masticatory system would be in harmony:)

    • Chris says:

      I can’t stop laughing at your comment, Rob!

      • rob, dmd says:

        Being a new dentist right out of school I don’t have a ton of clinical experience. Dental school has done a number on my TMJ. Also I had an incident around age 8 of trauma to the underside of my chin which may have contributed to my current TMD status. I experience disc displacement with reduction on the right side…no major pain except when I open too wide and the right condyle locks in the antero-superior position. This usually is so painful that I panic and forcefully bite down to move it back into place. I also have a left posterior cross-bite which may or may not contribute. My fear is that the reduction is going to disappear indicating that I have progressed to the next stage of TMD, and eventually that I’m going to be severely limited in function. What would be your recommendation?

        • Chris says:

          Hey Rob. It sounds like you are getting to the point where locking is happening more regularly, but a comprehensive TMJ examination is always in order. I would check your range of motion, palpate the muscles of mastication, and get a more complete history of your symptoms. My guess at this point is that the posterior ligament is becoming elongated at the lateral pole, which leads to the clicking/reduction. But now the posterior band is starting to thicken as it scrunched in front of the lateral pole, which leads to the locking. The good news is that this can still be predictably treated at this stage because the medial pole hopefully hasn’t starting clicking yet. After a full exam, I would make you an anterior bite plane to wear for a couple of days to determine if the disk will stay aligned after recapture. If load testing is negative and the symptoms have lessened or disappeared, then we would undergo a full occlusal equilibration to hopefully keep your occlusal-muscle system in harmony.

  21. Malia says:

    Hi Chris,
    I am currently in braces to straighten my teeth and fix an overbite. Currently, in order for my teeth to reach maximum intercuspation, I have to force my lower jaw forward into an unnatural position. In my habitual and relaxed bite, my teeth do not fit together as they should. I have brought this up with the orthodontist but he doesn’t think it is an issue, so long as there is a certain position in which I can reach maximum intercuspation. What are your thoughts on my situation?

    • Chris says:

      Mailia, it is possible that you could develop TMJ symptoms in the future if this is not corrected. While your teeth still being moved around it is expected that you will have some uncomfortable bites. However you’ll want to be more comfortable when the treatment is completed. Speak with your orthodontist and general dentist about your bite as the orthodontic treatment is finishing up to make sure you are comfortable.

Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>

Dental by Answers.com