Treatment of Temporomandibular Dysfunctions – TMJs

TREATMENT OF TEMPOROMANDIBULAR DYSFUNCTIONS – TMJS

Oftentimes dental patients refer symptoms such as pain upon closing or opening the jaw, or inability to bite confidently etc.

As extrapolated by large-scale studies, a significant prevalence of signs related to dysfunctions of Temporomandibular Joints and/or muscluture, is typically addressed among the generic population. Due to sub-clinical or cyclic occurrence of symptoms, very few patients however are becoming aware of their syndrome so as to seek suitable therapy.

  • facial pain or headache pain during mastication, speech
  • pain on the face/TMJs/teeth, triggered by eterotopic areas on the cerebral column and or the central nervous system
  • facial or headache pain at the preauricular site strongly mimicking earache pain
  • TMJ sounds induced during the movement of the jaw
  • Reduced opening or lateral deviation of the jaw upon opening
On occasion more complex signs occur, which can be misleading. Such can be toothaches, automatic stimulation of lacrimal glands (tears on one eye), discharge from the nose (single nostril) etc.

  • Trauma on the face, jaw or the cervix
  • Bruxism (clenching or grinding of the teeth)
  • New prosthetic restoration
  • History of Inflammatory diseases ie arthritis
  • Neuralgias originated in the central nervous system
  • Psychological traits
  • Predisposition due to specific anatomic/morphological features of the TMJs

Symptomatic_ Immediate relief from the symptoms is aimed in the very early phase. Treatment modalities are usually reversible-type in this early stage. Occlusal appliances (mouth guards) and/or selective grinding on centric relation are treatments of choice to accomodate dysfunctions of masticatory muscles or the TMJs. Specific methodology is employed to properly diagnose origin of pain – TMJs or masticatory muscles. Improper diagnosis leads to failed therapy. Hence, exacerbation of pain and metamorhosis on to chronic-type may terminally occur. As proper symptomatic treatment is started, pain typically recedes quite immediately. That improvement is a prerequisite as to proceed to the definitive therapy.   Etiologic_ Non-reversible-type therapeutic modalities aim to replicate the orthopedic stability as achieved with the mouth-guards to the natural dentition. Non-invasive bonded onlays and 360 veneers are mainly employed to fully reconstruct occlusion thus helping shift the mandible to a well-rested and asymptomatic position. Moreover orthodontic appliances are bonded to posterior teeth to optimize occlusal contacts and reassume orthopedic stability.  

Every type of restorative therapy i.e. filling , crown, bridge etc engages occlusal change , though in the majority of times with no significant impact on stability of the bite. However there are cases of prosthetic treatments in which a small alteration i.e a filling on the posterior teeth ,adversely affects occlusal stability. It takes even a tooth or implant to cause a full disorder of occlusion and to have an impact on masticatory system and the TMJoints

Tooth contacts on restorative treatment Ideal tooth contacts are investigated and fully described many decades back. Formerly a multitude of strict criteria were addressed to establish a perfect bite , as it was believed that occlusal issues was the major factor to fire TMDs. However, today only basic goals must be aimed in order to attain occlusal stability that facilitates smooth and painless function for all teeth, joints and the muscles Posterior contacts In the closing position specific criteria must be met on occluding posterior (back) teeth/restorations -Smooth , even and simultaneous contacts -Contacts on the long axis of the posterior (i.e on the fossa and the functional cusps) -No interference and/or no slide on the inclines of the teeth/restoration -No interference on the posterior teeth/restorations upon lateral and forward movements Anterior contacts In the closing position specific criteria must be met on occluding anterior(front) teeth/restorations -Smooth and simultaneous contacts on the labial surfaces of front teeth -Centric contacts on the anterior must be lighter than those on the posterior -When sliding to left or right only canines must be in contact

It is a prerequisite that any established functional disorder on TMJs and or the muscles (i.e . pain elicit upon jaw move/bite) be resolved prior to any restorative/prosthetic treatment.

In such cases a reversible therapy with an appliance/mouth guard on centric relation of the jaw (namely the most neutral jaw position- no muscle contraction) must precede.

Prosthetic restorations are considered small from single up to 3 unit restorations. In such cases habitual bite position is recorded and kept. Any small drift can easily be traced and relieved with selective grinding, so that occlusion remains stable.

On large prosthetic restorations it is apparent that lower jaw drifts due to consequent loss of occlusal stability. For example, when grinding 5 or more teeth/implants, habitual bite position is lost and driving muscles contract unevenly.

In such cases to build the prosthetic restoration, a stable and repeatable jaw position must be settled. For this reason optimal jaw position is centric relation namely the most neutral position at which all occlusal muscles are relaxed.

This position can be traced with several techniques i.e. bilateral manipulation, occlusal deprogrammer etc.

Centric relation provides ideal position to build large prosthetic restorations.

In treating occlusal instability there are two aspects

  • Additive aspect. With the aid of bonded restorations (i.e . composite /ceramic veneers ) and even with implants (when teeth are lost) we add materials in between the jaws. Biology-wise this treatment approach is considered favorable as opposed to subtractive. A small increase (2-4 mm) of the vertical dimension of occlusion can save intact teeth therefore provide for ‘’No cut&drill dentistry’’
  • Subtractive aspect. If for any reason, additive approach cannot be performed, selective grinding is applied. All contacts are traced and possible interferences are relieved both on posterior (if any) and the anterior teeth (if any) according to criteria that are aforementioned

Soft appliance is made of thermoplastic and is very appealing among dentists and the patients due to its small volume and to the easiness to put in place However as demonstrated in several studies, little or no actual relief has been noted among patients that used soft appliance In several studies that were conducted to compare soft vs hard splints, soft splints presented little or no accountability on addressing muscle activity whereas hard appliances showed a faster and more effective muscle relief In one study conducted by Okeson, maseter (major bite muscle) activity was marked higher in 5 of 10 subjects when they used soft splint, than that marked without the soft splint. That undoubtedly shows an exacerbation of bruxism when a soft appliance is used. Disclaimer: Always use hard appliance as orthopaedic device