TMJ Condylar Asymmetry

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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.

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TMD 2015, Condylar Asymmetry?

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Arthrogeneous origin of TMJ pain, Asymmetry, Asymmetry Index, Bruxism, condylar asymmetry recognition, Dentistry, Occlusal device, Retruded Position of the Mandible, Temporomandibular joint diagnostics, Temporomandibular joint disorder, Temporomandibular joint pain, TMJ rehabilitation, Treatment planning

Reflecting back on the interesting information given by eighteen well known international speakers at the Quintessence International Symposium on TMD & FACIAL PAIN and HEADACHE, Bridging the Gap Between Current Research and Clinical Practice in Scottsdale Arizona ( February 6-7,2015, Co-Chaired by Drs Daniel M.Laskin and Charles S.Greene ) I once again would like to stress the importance to recognize a temporomandibular joint condylar asymmetry when present. Several speakers stressed the overloaded temporomandibular joint as the cause of TMD and advised to pay less attention  to the masticatory muscles initially at  the examination of TMD pain. Lack of synovial liquid and mini ruptures or even nano ruptures of the joint tissues are to be looked upon as causes for cartilage degeneration with osteoarthritis / osteoarthrosis as the end result.

It is my opinion that in combination with bruxism a temporomandibular joint condylar asymmetry needs to be acknowledged and addressed. The shorter condyle side joint is in its morphology unstable and easily develops internal derangement of its articulating parts.  The well known phenomenon of disk displacement is thereby a fact and the first step in joint break down with the diagnosis Arthritis microtraumatica art.temp.mand. In this perspective occlusion becomes extremely important . The shorter condyle side joint needs to be supported with the correct vertical dimension of occlusion. What is missing in vertical dimension inside that joint needs to be compensated for at the level of the teeth of the ipsilateral side. In my mind this is the only possibility to create a stable occlusion with the maintenance of improved joint function after the initially reversible approach with an orthotic device.

Finally a statement/question that might need some thoughts: How much longer are we as a profession going to talk about occlusion without considering the vertical dimension of the two temporomandibular joints!?

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.