House of Gnathology part II

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Gnathology, Occlusion, TMD

On September 25th. 2016 I had the opportunity and  the great pleasure to attend the First Congress of the House of Gnathology in Turin, Italy.The Congress was the  successful result of two years preparation in gathering the different concepts of five different Italian societies regarding the approach in diagnostics and treatment of temporomandibular disorders.The initiative,taken some years ago, by Dr. Eugenio Tanteri involved the Associazone Italiana Gnatologia, the Accademia Italiana di Kinesiografia ed Elettromiografia Cranio Mandibolare, the Associazione Italiana Pedro Planas, the Società Italiana Disfunzioni ed Algie temporomandibolari and the Società Italiana Odontostomatologia dello Sport.

Each society was given ample time to present its ideas which ot course differed but were aiming towards general improvement in the daily work of the clinicians.It was even discussed to try to design a common  clinical examination protocol which could be promoted by any society in assisting the clinician in often difficult decisions.It is evident from listening to the colleagues that utmost few clinically useful examination criteria exist. Despite decades of attempts in  focusing on research diagnostic criteria for temporomandibular disorders their use in the clinical situation has not given any overwhelming impact on the daily work by the clinician.

I am looking forward to more cooperation between the researchers and the clinicians in the future and congratulate the House of Gnatholoy for this its first attempt in improving the care of thousands of suffering patients.

 

 

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Too many adjustments on the dental work?

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Asymmetry, Dentistry, Occlusal adjustment, Occlusion, Oral rehabilitation, Oral Stability, Retruded Position of the Mandible, TMJ rehabilitation, Treatment planning

Take a new panoramic X-ray or reevaluate the most recently taken one! Compare the vertical dimensions of the two temporomandibular joint condyles on the Ramus tangent. If they are not of equal height, start all over again and choose the higher condyle as the guide for your registration of the mandibular position to be used in the rehabilitation. In my opinion there is no other way to get the problem solved.
Merry Christmas and hopefully much less frustration and less adjustments in the Happy New Year!

Common Core in Dentistry?

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Centric relation, condylar asymmetry recognition, Dentistry, Occlusion, Oral rehabilitation, Oral Stability, Retruded Position of the Mandible, Treatment planning

Most likely it is the tooth. However, in 2015 that is neither good nor professional  enough. It is my opinion that it should be expanded to at least encompass the function of the whole masticatory system and to realise the importance of maintaining its bilateral uniqueness. In doing so the dentist, in the diagnostic phase as well as in the therapeutic phase, may enter into the dilemma of how to handle the treatment when the two temporomandibular joint condyles are not identical regarding their vertical dimensions.

In order to restore the occlusion and provide an oral stability with an optimal masticatory function the correct mandibular reference position needs to be found. At a temporomandibular joint condylar vertical asymmetry it may clinically be difficult to manually manage. The Maaxloc instrument by Dentatus should therefore be recommended. It assists the clinician in finding the mandibular position to be used in the rehabilitation, in guiding and directing the mandibular function around the higher and mostly normally developed temporomandibular joint condyle. Not considering a temporomandibular joint condylar vertical asymmetry, when present, is devastating  for the patient and the dentist.

Occlusal Adjustment at a TMJ Condylar Asymmetry?

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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.

Indices for jaw registrations

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Bruxism, Centric relation, condylar asymmetry recognition, Dentistry, Mounting casts, Occlusal device, Occlusal splint, Occlusion, Retruded Position of the Mandible, TMJ rehabilitation

Sometimes it can be difficult to get a relaxed mandible in the process of jaw registration in the retruded position of the mandible in as well the diagnostic phase as in the steps of treatment. It happens mostly when the patient is a heavy bruxer or when the patient seems to defend him/herself against the pressure from the hands of the dentist in the clinical situation. A condylar asymmetry may add to the clinical difficulty in getting the registration right.
With the measurements of the vertical dimensions of the temporomandibular joint condyles and the Maaxloc device at hands the above mentioned problems can definitely be reduced.It is my opinion, which to a great extent I have achieved from the dental technicians, that the registrations made in the Maaxloc system get into a more retruded position of the mandible in comparison with the manually taken clinical indices which often are protruded.This conclusion is based upon several years of cooperation with Ines Selimanovic T.I.C. laboratory, Malmoe ,Sweden, an experienced dental technician, with whom I have made comparisons of by me taken clinical indices and by her made registrations in the Maaxloc device.
In conc;usion: To avoid unnecessary and time consuming adjustments despite quality of the dental work in the ” difficult mouth “it might be worth while to become critical to the manually taken clinical registration and consider the advantage of the Maaxloc device.

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.

Cutting Temporomandibular Joints

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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

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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.

 

Occlusal ” interferences ” at condylar asymmetry

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

must be carefully evaluated before any action is taken. It is as important and necessary to realize as it is absolutely wrong to adjust occlusal  pre contacts in the acute situation of functional facial pain.The latter  ” interferences ” may not be real as they might not exist under normal or pain free circumstances. They might be due to changed muscular conditions in the dysfunction of the stomatognathic system and most probably they will disappear with a normalization of the function. In my opinion it is therefore an absolute necessity to always normalize the muscle function via reversible means before any change of the occlusal surfaces takes place. This is done through the insertion of a stabilization splint made in the correct mandibular position, based upon the findings of the condylar heights visible in the panoramic x- ray, and worn according to the preliminary diagnosis during 4-6 months . Not until then an occlusal adjustment can be considered.

Although occlusal pre contacts cause an oral instability with mostly a slide between the retruded position of the mandible ( RPM ) and the intercuspal position ( ICP )  pre contacts on the ” higher condyle ” side may indicate the true vertical dimension of the occlusion ( the static relation between the teeth of the maxilla and of the mandible ).Therefore these contacts will function as the guide  for an increase of the vertical dimensions of the teeth not in contact  on the opposite side in equivalent regions. Thus ,it is my advice that, occlusal pre contacts on the ” higher condyle ” side should not be removed. If so, there is a major risk that the vertical dimension will get decreased and problems due to a too low vertical dimension of the occlusion will occur.

Occlusal pre contacts on the ” shorter condyle ” side  in the retruded position of the mandible ( RPM ) most likely are true interferences and can therefore be removed after a normalization of the muscle function. They should also be removed prior to the introduction of new elements into the occlusion via prosthodontics.

At condylar symmetry i.e. when the two condylar heights are of equal size, pre contacts in the retruded position of the mandible ( RPM ) should be removed pre prostodontically. If no further rehabilitation is planned or indicated these pre contacts can be left unless they produce a  major lateral slide between the retruded position of the mandible ( RPM ) and the intercuspal  position (ICP ).The general rule remains: DO NOT CONTRIBUTE TO UNNECESSARY CHANGES OF THE OCCLUSION IN A PATIENT WITHOUT PAIN !  NEVER APPLY  OCCLUSAL ADJUSTMENT AS A PURE PREVENTION !

Maaxloc, the mandibular axis locator

Tags

Asymmetry, Bruxism, Centric relation, condylar asymmetry recognition, Condyle (anatomy), Dentistry, Occlusion, Radiography, Retruded Position of the Mandible, Temporomandibular joint, Temporomandibular joint diagnostics, Temporomandibular joint disorder, Temporomandibular joint pain

Several years ago I met with and was introduced to Kenneth Wallenholm, an experienced dental technician in Stockholm, Sweden. I was giving a lecture and he was in the audience. I had talked about the recognition of temporomandibular joint condylar asymmetry, when present, and its importance for a correct registration of the mandibular position to be used as the reference position for optimal dental work clinically as well as in the dental laboratory. He had immediately understood my message and for a long time also realized that most “wax bites”, indices or ” Registrat ” accompanying dental impressions into the laboratories most frequently ended up in the trash can, never being used. The reason was that these ” wax bites ” did not provide any information about the workable intermaxillary relation. The technicians therefore rather related the upper and lower models of the jaws by hand i.e. they just tried to find the best stability between the models,maybe sometimes the intercuspal position, before they started their technical procedures to establish an acceptable occlusion. We were  both of the same opinion that such unfortunate events outside the mouth of the patient are the major reasons  for clinically unwanted adjustments of dental work before its  insertion into the mouth.

It did not take us long time until we met again and started to brain storm how to come up with a device in order to facilitate for the dentist / technician team to ascertain and improve the registration of the correct mandibular position to be used by both the professions. After many hours, many different measurements, several different drawings and a certain number of pieces of ” metal constructions ” the patent was approved and the prototype for the Maaxloc  was completed by Dentatus ( info@dentatus.se : dentatus@dentatus.com )

The Maaxloc determines the clinically correct mandibular position. The Maaxloc is not an articulator even if it is described under articulators in the list of products from Dentatus. The Maaxloc is a device to assist in finding the correct mandibular position of reference at a recognized condylar / mandibular asymmetry. The registration index produced in the Maaxloc can be  used in any articulator of your choice and can comfortably be applied in cases of craniomandibular or temporomandibular disorders,as well as in any case of prosthetic rehabilitation or orthodontic analysis. Determining the correct mandibular position of reference is of utmost importance and will help to avoid unwanted occlusal features. This includes achieving the correct incline of implants into the jaws and improving the occlusal analysis before an orthodontic treatment is initiated.

The Maaxloc is time saving and reduces pain because:

1.Symmetry in occlusal contacts between the jaws decreases the risk of failure in providing bilateral load to the stomatognathic system.

2.Less time is spent on adjustments and on remakes due to fractures in veneers and crown & bridge work, including supra structures on successfully accepted implants.

3.Shorter sessions for repetitive registrations of the mandibular positions.

4.A stable occlusion compensates a morphological asymmetry, improves the general adaptation of tissues and is especially beneficial to the edentulous patient wearing removable prostheses, with less dislocation of the prostheses.

5.Last but not least, once the individually correct mandibular position has been found, the patients immediately acknowledge their natural way of achieving and sensing oral stability

It  is my convinced opinion that the measurements of the condylar heights in a panoramic ( overview ) x-ray and  the difference between the two sides transferred into  the Maaxloc will further your clinical success and confidence.