Reversible Oral Stability, One Splint and that’s it

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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 !

 

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Maaxloc, the mandibular axis locator

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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.

The Mandibular Position and The Hinge Axis

Tags

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

It is impossible for me not to repeat the importance in every clinical situation to recognize a temporomandibular joint condylar asymmetry, when present. In not doing so the treatment cannot be correctly predicted. The treatment will not be as successful as was expected . Unnecessary adjustments of oral devices or, even worse, adjustments of permanent dentistry will disappoint the patient as well as the dentist with also the risk that the treatment will never be fully accepted despite tremendous efforts from both parties involved.

In the clinical situation or in the dental laboratory the conventional axis of mandibular rotation should never penetrate the centers of the two temporomandibular joint condyles at a condylar asymmetry.One condyle, the ” higher one “must determine the axis of rotation. If not, the axis of rotation could not be parallel to the horizontal plane, used as the reference at general rehabilitation.

                                                  Wrong axis of rotation at a condylar asymmetry.

CORRECT AXIS OF ROTATION AT A CONDYLAR ASYMMETRY.

It is my opinion that the definition and the application of the generally used retruded position of the mandible ( RPM ),based upon the assumption that the two temporomandibular joints are equal, therefore needs to be reconsidered and slightly adjusted Clinically I have always worked with the retruded position of the mandible as my reliable position of reference.However for the past 25 years I  have advocated that the retruded position of the mandible ( RPM ) is ( should be ,if not yet ) determined and guided by the normally developed and functioning temporomandibular joint condyle. When the right side is the higher side RPM is to be written RPM (R). When the left side is the higher side RPM is to be written RPM (L) and when the two condyles are of equal height RPM is to be written RPM (=).In addition, when the two condylar heights are measured in the panoramic ( over view ) x-ray and the magnification factor  of the machine is compensated in the calculation the RPM(R) or RPM(L) at an asymmetry can be written i.e. RPM(R)1,5mm or RPM(L) 0,5 into the clinical documents. In that way the almost true difference between the two condylar heights easily can be compensated for in the necessary index to be used in the phase of rehabilitation clinically or at the laboratory via the Maaxloc device (info@dentatus.se)

In general the higher condyle determines what side is to be the guiding side for RPM. However, there is one exception under rare circumstances.At a ramus asymmetry when the total vertical dimensional difference between the two mandibular sides is determined by a major difference in height of the two rami, the vertical dimensional difference determined by the condyles is overruled.Then the biggest total mandibular vertical height may direct even the “shorter condyle” to be the guide in the registration of the retruded position of the mandible and the center of the hinge axis rotation. In this context “disturbing” precontacts or interferences enter a completely new perspective. Unilateral tooth contacts on the “higher condyle” side may indicate the correct vertical dimension of the occlusion. The lack of tooth contacts on the “shorter condyle” side may indicate the occlusal dimension that needs to be increased.Only interferences or precontacts on the “shorter condyle” side will then remain as traditional interferences i.e.disturbing tooth contacts.

Team Approach in tmj Condylar Asymmetry Recognition and rehabilitation( TACAR )

Tags

condylar asymmetry recognition, Temporomandibular joint diagnostics

For many years during and after given lectures and courses I have been asked to guide and to assist in the diagnostics and treatment of facial pain and often facial asymmetry due to a vertical temporomandibular joint condylar asymmetry.Often dentists do not consider the phenomenon, a possible vertical temporomandibular joint condylar asymmetry, when their utmost perfect occlusal rehabilitation fails. It is not that strange as mostly the two temporomandibular joints were not considered in the planning and design of the prosthodontics or orthodontics.There may be several explanations and  reasons.Some of them may be ascribed to facts like:

1. The temporomandibular joints are often pictured in a sagittal plane and one at the time,

2.The two temporomandibular joints are learnt and conceptualized as being identical,

3.An occlusal adjustment is something that is considered almost “normal “, when ” the work ”  returns from the dental laboratory before it’s permanent insertion into the mouth,

4.Occlusal devices need to be adjusted as the patient might be a tooth grinder or a tooth clencher,

5.The two temporomandibular joints may not be or were not visible in the panoramic radiograph (if even taken ) or

6.The dentist was taught that the panoramic radiograph is not reliable and that all dimensions in the pictureare are not trustworthy and so on.

From January 2014 on I will try to provide an exchange of experience and ideas through this blog on at least a weekly basis. The blog will address clinical and practical problems . My intention is to share my experience of more than 30 years in dealing with tmj condylar asymmetry.The readers are most welcome to ask questions and hopefully the blog will stimulate to new discoveries and even to convince the very conservative part of the dental profession to recognize and to compensate for an existing temporomandibulr joint condylar asymmetry when it is confirmed to be the cause for the facial pain in the patient.