Occlusal Adjustment at a TMJ Condylar Asymmetry?

Tags

Asymmetry, Centric relation, condylar asymmetry recognition, Dental treatment, Dentistry, Occlusal adjustment, Occlusion, Preprosthetic occlusal adjustment, Retruded Position of the Mandible, TMJ rehabilitation, Treatment planning

Be careful! The tooth contacts which seem to be occlusal interferences at the first sight when the conventional retruded contact position of the mandible is being executed may not be disturbing tooth contacts at all. If they are located on the higher condyle side they may denote the vertical dimension of the inter maxillary relationship and should in my opinion not be removed. Only precontacts on the shorter condyle side are to be looked upon as true interferences and can be removed to such an extent that tooth contacts are established on the higher condyle side.

With the risk of repeating myself I  do want to advise the clinician to build up the occlusion on the shorter condyle side instead of adjusting the teeth through occlusal adjustment on the higher condyle side.In this way we will secure a correct vertical dimension between the two jaws in occlusion and thereby rescue the patient from a too low vertical dimension of the occlusion after completed dental work often jeopardising the function the temporomandibular joints.

TMJ Condylar Asymmetry

Tags

Arthrogeneous origin of TMJ pain, Asymmetry, Asymmetry Index, Centric relation, condylar asymmetry recognition, Dentistry, Oral rehabilitation, Oral Stability, Orthodontics, Retruded Position of the Mandible, Temporomandibular joint diagnostics, Temporomandibular joint disorder, TMJ rehabilitation, Treatment planning

when present,is a must to consider, in any dental rehabilitation. I dare to have this opinion after more than three decades of experience in treating ” asymmetrical ” patients shared with several successful colleagues. Although I repeat my opinion   it seems relevant as we on a regular basis are exposed to excellent crowns, bridges,supra constructions on implants and even completed orthodontics and yet a not satisfied patient.The chosen mandibular position for the rehabilitation in the majority of these patients has not been correct.

Results of recent research performed in different countries indicate that the mechanics of the temporomandibular joint is essential in order to maintain a pain free and functioning stomatognathic system (Quintessence International Symposium, Scottsdale,Arizona February 6-7, 2015). Overloading of the joint seems  not only to jeopardize the intraarticular structures of the joint resulting in anything from internal derangement to osteoarthritis but also to be the trigger for masticatory muscle pain.

At a vertical temporomandibular joint condylar asymmetry the loading of the two joints is in danger as the vertical dimensions of the two condyles are not equal. Therefor the vertical dimensions of the two temporomandibular joint condyles need to be analyzed before any treatment is initiated. It is of utmost importance to determine the highest condyle as at an asymmetry  this condyle has to be the guide for the mandibular movement of  rotation(the Retruded Position of the Mandible)in which the rehabilitation is going to be executed.

Additionally,in patients with functional facial pain it sometimes might be difficult to clinically manipulate the mandible into the correct position for rehabilitation. At such occasions the result of the vertical condylar analysis in the panoramic X-ray easily can be transferred into the Maaxloc device by Dentatus, in which the index for the mandibular position of the planned rehabilitation is made.

House of Gnathology?

Tags

Arthrogeneous origin of TMJ pain, Asymmetry, Bruxism, Centric relation, condylar asymmetry recognition, Dentistry, Myogeneous origin of TMJ pain, Occlusal adjustment, Oral Stability, Retruded Position of the Mandible, Temporomandibular joint diagnostics, Temporomandibular joint disorder, Temporomandibular joint pain, TMJ rehabilitation, Treatment planning

A week ago I had the pleasure to attend the XXVII International AIG (Associazione Italiana di Gnatologia) Congress in Torino, Italy. Twentyseven speakers from six countries each had about 30 minutes to present their thoughts about the relationship between occlusion and temporomandibular joint disorders. In general it could be concluded that a stable occlusion would improve the function of the stomatognathic system and thereby reduce the risk for developing or aggravating a temporomandibular joint disorder. It was also underlined in several lectures that gnathology is a team work and that occlusion is one tool in the treatment of a temporomandibular joint disorder.
It was interesting to note that the speakers in general agreed in finding occlusion an important factor in the treatment of a temporomandibular joint disorder, i.e. a complete contradiction to the conclusion of several hundreds of articles and studies proclaiming that when RDC/TMD are used in the evaluation of treatment outcome occlusion is not important and should not get priority or most often not even be considered in the treatment of a temporomandibular joint disorder.

RDC/TMD were discussed and by a great part of the participants even questioned in the final round table discussion of the congress. In my opinion and in agreement with many other clinicians RDC/TMD cannot and should not be used in the clinical situation in which a specific diagnosis is to be the sound base for the treatment. Reliable criteria like maximum mouth opening, mandibular movements, the difference between dynamic and static pain and even the difference between the vertical dimensions of the two temporomandibular joint condyles visible and measurable in a panoramic X-ray exist. Therefore my suggestion to the RDC/TMD supporters is: Next time you conduct a clinical study, why not incorporate the above mentioned criteria! I am pretty convinced that the results will be different regarding the eventual link between occlusion and the temporomandibular joint disorder.

Finally I would delete the ? from the title of this blog and agree with the suggestion from Dr.Eugenio Tanteri that a forum “House of Gnathology” might come to an agreement that a correctly designed and applied occlusion is important in providing  oral stability and thereby reduce the prevalence of temporomandibular joint disorders among our patients.

Tinnitus and TMD

Tags

Asymmetry, condylar asymmetry recognition, Dentistry, Occlusal device, Occlusal splint, Oral Stability, Temporomandibular joint disorder, Tinnitus, TMJ rehabilitation, Treatment planning

Tinnitus in itself is not an indication for dental intervention. However,if tinnitus is mentioned at an examination of facial pain of either myogeneous or arthrogeneous origin there may be a chance to influence its existence. After reviewing some records of patients some years ago and present experience it is my opinion that it is about one third of the patients suffering tinnitus and TMD who will notice a reduction or even a total elimination of their tinnitus from oral stability initially from a stabilization splint compensating for a temporomandibular joint vertical condylar asymmetry, when present.

As it was just one third who reported a benefit regarding their tinnitus it must be up to the patient to decide if it is worth while to invest in an oral device fighting tinnitus. Objective information regarding a dubious result should precede the decision. It is also  important to tell the patient that very often the relief from tinnitus does not come immediately after the insertion of the device. It is reported by several patients that it could take a couple of months before they noticed a difference in their tinnitus. In conclusion: When a stabilization splint is being delivered  in trying to influence a tinnitus the patient might have to wear the splint several months before a change occurs  and before one actually knows if it was beneficial or not. 

Mounting casts

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Asymmetry, Asymmetry Index, Centric relation, condylar asymmetry recognition, Dental laboratory work, Dentistry, Mounting casts, Occlusal adjustment, Occlusal device, Occlusal splint, Occlusion, Oral rehabilitation, Oral Stability, TMJ rehabilitation, Treatment planning

The other day I had to check the mounting of the casts of the upper and lower jaws of a patient with a condylar asymmetry of about 6%. The reason for my visit to the dental laboratory was that the right side lower four units bridge had been redone and several times before that adjusted. And yet the patient found it too low i.e. her teeth of her right side did not contact in occlusion unless she  forced her mandible to the right.

During the visit at the laboratory it became once again obvious to me from the discussions with two well experienced dental technicians that very often the indices to be used in mounting the casts cannot be used. The indices are perforated and mostly show slides in the material used indicating that the mandible of the patient has not been stable at the time of index registration.  Therefore the technicians try to analyze different facets of the occlusal surfaces of the casts. They try to fake the movements of the patients mouth that have created them and thereafter, still manually, they fix the casts in the position which seems to  be the starting point for the suspected movement.This position usually is looked upon as the intercuspal position and will be used for the subsequent mounting of the casts.

At a condylar asymmetry it is therefore easy to understand that with the above described mounting of the casts the crowns or bridges of the ” shorter condyle ” side will be too low. Clinically oral stability will be lacking despite the insertion of the prosthodontic work. Very often tooth contacts of the ” higher condyle  ” side will be looked upon as occlusal interferences and removed in an ” adjustment “.This actually results in a decrease of the vertical dimension and a not one hundred percentage satisfied patient.

The problem and frustration can easily be avoided if the vertical condylar asymmetry is transferred into the Maaxloc instrument. A registration at the clinic or at the laboratory is made  and used in mounting the casts with the result that mostly the prosthodontic work can be inserted  without any adjustment at its delivery.

Asymmetry Index ( AI ) for temporomandibular joint Condylar Asymmetry

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Arthrogeneous origin of TMJ pain, Asymmetry, Asymmetry Index, Centric relation, condylar asymmetry recognition, Dentistry, Myogeneous origin of TMJ pain, Occlusal adjustment, Oral rehabilitation, Oral Stability, Retruded Position of the Mandible, Reversible treatment, Temporomandibular joint, Temporomandibular joint diagnostics, Tension headache, TMJ rehabilitation

For more than twenty years I have been working on a regular basis with Dr Ugo Gambardella, Medical Space in Seriate, Italy. In 1993 we founded the T.A.C. Seriate clinic, ( Team Approach to Craniomandibular disorders ) in order to optimize the diagnostics and treatment of patients suffering facial pain due to dysfunction of the stomatognathic system. Dr Gambardella was already then experienced in prosthodontics as well as in implantology.
Already at the start it became obvious to us that a large portion of the mostly referred patients showed a condylar asymmetry and a lack of oral stability. Initially our treatment aimed at a normalization of the stomatognathic system via a stabilization splint in its design compensating for the condylar asymmetry, when present, and providing at least a temporary oral stability. After 6 – 12 months several patients wanted to have permanent oral stability, which then was achieved through mostly prosthodontics , sometimes in combination with preprosthetic orthodontics.
Some years ago and then more than 5 years after completed treatment the patients were invited to have their situation evaluated and to tell how they felt and how they were functioning after treatment. The equivalent clinical examination of their stomatognathic system was executed by an Italian speaking colleague, who did not know what kind of treatment the patients had got or been exposed to. The teeth depicted in the panoramic overview X-rays were covered i.e. made not visible to the examiner while the two temporomandibular joints were shown.
The condylar asymmetry was analyzed and for each patient an Asymmetry Index ( AI ) was calculated according to the following formula: ( R – L : R + L ) x 100 i.e. the right side condylar height minus the left side condylar height divided by the sum of the right and left side condylar heights multiplied by 100. Thus an asymmetry index was expressed in percentage for each patient.
The results of the subsequent analysis showed that after more than five years with permanent oral stability no patient any longer was found with a mainly arthrogeneous origin of pain. Myogeneous origin of pain was also frequently eliminated or markedly reduced. All patients showed an increase of maximum mouth opening.
The patients were grouped and analyzed according to the asymmetry index ( AI ) . It can be concluded from the results that patients with an AI > 3 % in general benefit from reversible treatment. Patients with an AI in the range between 3 % and 10 % may do well with just a temporary oral stability in form of a stabilization splint i.e. the splint can be worn part time, which for most patients means during sleep. As the participating patients with an AI > 10 % definitely benefitted the most and also felt subjectively completely different, mostly totally pain free after the treatment it is our opinion, that when you find a condylar asymmetry > 10 % in a patient with a diagnosed facial pain, you can comfortably suggest permanent occlusal treatment after the initially reversible period in the correct mandibular position guided by the higher temporomandibular joint condyle. The permanent treatment then executed in the same mandibular position will provide oral stability.

TMJ Clicking Sound

Tags

Arthrogeneous origin of TMJ pain, Asymmetry, Centric relation, condylar asymmetry recognition, Dentistry, Myogeneous origin of TMJ pain, Retruded Position of the Mandible, Temporomandibular joint, Temporomandibular Joint Clicking, Temporomandibular joint diagnostics, Temporomandibular Joint Disk Displacement, Temporomandibular joint pain, Temporomandibular Joint Sounds

TMJ clicking sound has been reported, discussed, investigated and even visualized in thousands of articles during the past thirty and more years with a peak of interest in 1980-s. Common knowledge is that the sound is either due to deviations in form of the articulating surfaces of the condyle and / or the temporal component ( increase of cartilage in specifically overloaded areas of the articulating surface ) or to a displacement of the disk. Disk displacement often comes and goes and it is therefore not a surprise that it is more common among patients with a mainly myogeneous origin of pain. Since the result of comprehensive epidemiological  studies in the 1970-s it is also common knowledge that  the phenomena occurs in about 40% of the adult population.

Hopefully in not contributing to the too often clinically existing confusion of how to handle the sound I would rather suggest the following: Check the panoramic x-ray i.e. check specifically the temporomandibular joint condylar heights before you take any further steps in your attempt to help your patient!

Most probably you will find a shorter condyle of the joint with the registered clicking sound. Try to guide a mandibular rotation movement around the higher condyle and most likely the clicking sound disappears or at least gets a reduced  magnitude, when it is due to a latent disk displacement. If there is no discomfort or pain to be registered there is no real indication for intervention. However, if discomfort or a mainly myogeneous origin of pain is reported by the patient there is a need for an initially reversible treatment in form of a stabilization splint that compensates for the difference in vertical dimensions between the two condyles. The splint is to be worn part time . The patient is supposed to find a seemingly fast relief.  When the clicking sound is found in combination with a mainly arthrogeneous origin of pain the splint needs to be worn as much as possible for at least 6 months before additional permanent treatment is considered.

In addition , even if the clicking sound is due to a deviation in form ( of the condyle and / or of the temporal component )  the clicking sound may over time get reduced as a smoothening out of the articulating surfaces can be expected at a consequent long term  wearing of the correctly designed splint. Therefore I once again would suggest the use of the Maaxloc instrument in producing the index  which will be used in mounting the models into the articulator before the construction of the stabilization splint. The splint absolutely must compensate for the registered difference in vertical condylar height between the two joints in providing a symmetrical oral stability in order to eliminate the  painful and bothersome  tmj clicking.

Sleep Apnea Oral Devices

Tags

Arthrogeneous origin of TMJ pain, Asymmetry, condylar asymmetry recognition, Dentistry, Myogeneous origin of TMJ pain, Occlusal device, Sleep Apnea, Sleep Apnea Device, Temporomandibular joint, Temporomandibular joint diagnostics, Temporomandibular joint dysfunction, Temporomandibular joint pain, Treatment planning

Nowadays MAD, the mandibular advancement device, seems to be delivered from almost every dental office in an effort to assist the medical profession fighting sleep apnea, a major problem for many of our patients. The device is supposed to direct the mandible forward and inferiorly in order to increase the air flow through the mouth. However, a standardized method in making the device seems lacking and many patients suffer discomfort or pain after wearing the device after various lengths of time. Dentists regularly also register changes of occlusion, most often posterior open bites.

As the device shall position the mandible forwards the most often clinically achieved index accompanying the impressions to the laboratory must be taken in a protruded mandibular position. But how much protrusion seems to be left at random. There are studies concluding that it does not matter whether the protrusion is 75% of maximum protrusion or only 25%. Nevertheless it seems accepted to allow a rather large amount of protrusion as additional protrusion as adjustment of the device  often is recommended in the cases where the originally designed device has not given the expected relief.

At a vertical temporomandibular joint condylar asymmetry an excessive and prolonged protrusion definitely puts the comfort of the patient and a  harm free function of the stomatognathic system at risk. At a vertical condylar asymmetry most likely the clinically taken index does not register the mandible in a symmetrically protruded mandibular position. Most likely the mandible is deviating towards the ” shorter ” condyle side. To then have this position maintained during six to eight hours of sleep with thus an awkward  and asymmetrical muscle function and temporomandibular joint condylar positions may be one reason for discomfort or facial pain at awakening.

One way to avoid the problem is to use the Maaxloc ( following the analysis of the vertical condylar heights in the panoramic x-ray ) in constructing the index which is to be used in the mounting of the models in the articulator. It is then easy to bilaterally just set the amount of individually determined protrusion to be applied in the fabrication of the device. A symmetrical protrusion is thereby achieved resulting in a more comfortable device.

A good friend of mine, Dr Staffan Lindholm, Stockholm, Sweden, is probably one of the most experienced dentists in Scandinavia when it concerns oral devices  in fighting sleep apnea. His expertise and unusual self criticism already several years ago  motivated him to compare the outcome of 59 conventionally and from just clinically taken indices  oral devices with another  59 devices constructed from articulator set protrusion of the models mounted with the Maaxloc registration. Six patients of the first group suffered pain and discomfort from  their devices while only 1 patient of the second group showed a minor dissatisfaction, but tolerated the splint. The 6 not successful devices in the first group of  patients were later adjusted according to a Maaxloc registration resulting in patient satisfaction.

In many discussions with fellow dentists and dental technicians Dr. Lindholm  proclaims the superiority of the Maaxloc instrument in constructing a more comfortable  and successful oral device. He is happy to generally tell about his continuing success with a 80-90% reduction of the risk to develop discomfort or pain in the patients who are forced to wear an oral device fighting sleep apnea by using the Maaxloc registration in mounting the models before its fabrication in the laboratory . In conclusion, please do consider a correct index in protrusion for the construction of any anti sleep apnea device at your choice and thereby enjoy a major increase of clinical success!

Cutting Temporomandibular Joints

Tags

Asymmetry, condylar asymmetry recognition, Dentistry, Implantology, Occlusion, Orthodontics, Preprosthetic occlusal adjustment, Prosthodontics, Radiography, Temporomandibular joint, Temporomandibular joint disorder, Temporomandibular joint pain, Treatment planning

occurs in surgery. Thank God it does not happen too often, as responsible, well trained and experienced oral / maxillofacial surgeons are utmost cautious. They know it is involved with major draw backs. However, under certain circumstances and with the correct indications it is  necessary. I do not mind that at all, but what I do mind is all the cutting of temporomandibular joints in the panoramic x-rays we are exposed to in the literature and thus unconsciously gives us the message that the joints are not so very important.

It does not matter whether it is in a professional journal of prosthodontics, orthodontics, implantology, periodontics or even in a presentation at a congress it could be estimated that 8-9 out of 10 panoramic x-ray photos presented do not show the entire picture of the two temporomandibular joint condyles. The majority of condyles are cut totally  or at least partially while all the teeth are nicely depicted and aligned in the perfect occlusal plane  often before as well as always after treatment.  Is a vertical condylar asymmetry present in such a patient most likely the teeth are not aligned in the shown or anticipated correct occlusal plane. With a high probability the smile of that patient is tilted which is observed in the clinical situation and which often also might be the reason for the complaint of  the not satisfied patient.

In rehabilitation priority is supposed to be given to the whole stomatognathic system and not only to one third of it. As the other two thirds of the system ( the masticatory muscles and the two temporomandibular joints ) are dependent on the teeth it is my advice that the teeth must be aligned in such a way that they vertically compensate for what is missing in the vertical dimension of the shorter condyle when present. Addressing the vertical condylar asymmetry, when present, is of utmost importance and  in my opinion it should be done already at the time of treatment planning regardless specialty of the therapist. To incorporate an index, preferably via Maaxloc, between the models already at the initial analysis of the ” study ” models instead of just manually having the models to occlude will definitely contribute to a bigger certainty in reaching the goal of treatment. It makes the whole planning easier and it decreases the risk of unnecessary difficulties during treatment. In not accepting cut temporomandibular joint condyles in the panoramic x-ray and instead  only accepting  the picture when it is  complete i.e. picturing  both the temporomandibular joint condyles we most probably will be  expanding our clinical success and consequently patient satisfaction.

Uneven Front Teeth Wear

Tags

Asymmetry, Bruxism, Centric relation, condylar asymmetry recognition, Dentistry, Occlusal device, Occlusal splint, Occlusion, Orthodontics, Preprosthetic occlusal adjustment, Retruded Position of the Mandible, Reversible treatment, Temporomandibular joint, Temporomandibular joint disorder, Temporomandibular joint pain, Treatment planning

may very well denote a temporomandibular joint condylar asymmetry and may therefore indicate the necessity of a panoramic x-ray in order to avoid negative consequences of a dental treatment. It is my experience that very often the front teeth ( the central and the lateral incisors ) of the quadrant of the ” higher condyle ” side are more worn than the equivalent teeth of the contra lateral side. The ” higher condyle ” side seems with a far more higher prevalence be used as the laterotrusive side ( working side ). The contra lateral side of the face then also looks bigger or thicker, most probably due to the unilateral hyperactivity of the superficial masseter muscle of that side. When this kind of an observation is made there is an absolute indication to proceed with a clinical examination in order to rule out whether pain or discomfort are involved.

If pain is present the stomatognathic system needs to get normalized. This is easily accomplished with the insertion of a correctly designed stabilization splint. The splint preferably already at the dental laboratory is  fabricated in the correct relation between the models i.e. the models have been mounted in an articulator according to the index ( registration ) made in the Maaxloc and thereby based upon the difference between the two condylar heights. Within a couple of weeks, not to say surprisingly often within a couple of days, the patient returns with markedly reduced pain or completely without pain. Also without any difficulties the patient normally finds his / her natural way in getting his / her teeth together. However,on the ” shorter condyle ” side tooth contacts are missing. This most often results in a slide between the mandibular reference position, RPM, and the intercuspal position and therefore often indicates a need for extended dental treatment or at least a change of direction of your earlier planned treatment.  The empty space between the teeth of the ” shorter condyle ” therefore needs to be filled in or the teeth of the ” shorter condyle ” side need to be built up. After four to six months and with a reversible approach in form of a partial and casted metal splint cemented on the not occluding teeth of the ” shorter condyle ” side oral stability is achieved. Personally I always have that splint casted in gold and made for the lower premolars / molars. The earlier worn stabilization splint is being adjusted to the new and reversible occlusion and is used part time, during sleep for an individually determined length of time. Finally permanent treatment can be considered at the choice of you and your patient.

Uneven front teeth wear occurs and is also sometimes observed in young patients.In these individuals it may be even more important to analyze the vertical dimensions of the two temporomandibular joint condyles. At a condylar asymmetry an index via Maaxloc may serve as an adequate guide to relate the upper and lower models of the teeth, indicating the correct vertical dimensions of the jaws after completed treatment and thereby contribute to the best outcome of the orthodontic treatment. In not addressing the condylar asymmetry, when present, in the initial phase of treatment planning there is always the risk to deliver a yet perfect occlusion but in a not perfect occlusal plane, i. e. a perfect smile what concerns the teeth but less perfect what concerns the smiling mouth of the whole face.