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.

Indices for jaw registrations

Tags

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.

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.

 

Reversible Oral Stability, One Splint and that’s it

Tags

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

Through the insertion of a stabilization splint fabricated in the correct mandibular position i.e. in RPM(=),RPM(R) or RPM(L) it is easy ,not to say the only way, to confirm or justify the preliminary diagnosis of the complaint of facial pain.Needless to say , I take for granted that the mandibular position is determined from the analysis of the vertical dimensions of the two temporomandibular joint condyles visible in the panoramic x-ray. The values conclude with the difference in mm provided the technician with the impressions of the upper and lower jaws. Via Maaxloc you or your technician produce the index with which the models are mounted into the articulator of your choice. The splint is fabricated in hot curing acrylic and at a condylar asymmetry it will be somewhat thicker at the ” shorter condyle ” side ,as it is compensating what is missing in the vertical dimension of that condylar height. The splint does not need to be adjusted if your measurements and impressions/models are correct. It fits directly into the mouth of your patient. There are many hard and good working technicians who perfectly provide excellent splints. My opinion is that if the dentist needs to adjust a splint the error most likely must have happened in the clinical situation as the technician is working with the models of non changeable materials and correctly mounted in the articulator.

The patient is then to wear the splint depending upon the preliminary diagnosis. Full time use, 24 hours a day, except at eating at arthrogeneous origin of pain as the anatomical joint structures need support. Part time use of the splint, day OR night, at myogeneous origin of pain as the masticatory muscles needs to be interrupted in their hyperfunction  i.e. given the possibility to rest. I do think that the reason why even  perfectly fit splints do not give the patient any relief is that the splint is worn at the wrong time of the 24 hours. To wear a splint during sleep when bruxing occurs during the day does not make any sense to me. Just a change in the way the patient is wearing the splint may result in complete relief.

Personally I never prescribe soft splints. In my opinion they function as chewing gum due to their resilience and should be avoided in any bruxing situation. In conclusion, there is only one splint that also can be looked upon as universal . That is the conventionally made stabilization splint  ( the old Michigan splint ) fabricated around the correct mandibular position in RPM. No problem All continents !

 

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.