This article will assist the legal professional
in the determination of temporomandibular (TMJ) injury and whether or
not it is related to trauma. The TMJ or jaw joint is the joint
immediately in front of the ears. Although this joint is frequently
injured these TMJ injuries are often misdiagnosed and have only recently
received widespread attention. The temporomandibular joint is unique in
that this joint dislocates itself within its ball and socket arrangement
so the jaw can fully open. This intricate arrangement lends the TMJ
susceptible to injury during traumatic episodes such as rear-end
collisions involving cervical whiplash and other blows to the face.
Pain disorders often head and neck in general and TMJ dysfunctions in
particular are complex disorders and are difficult to diagnose precisely
and treat effectively. These disorders are progressive and, if left
untreated, can increase the range of functional implications which can
be devastating to the patient. Few medical and dental practitioners have
the specialized training and experience in such disorders.
How Does the TMJ Injury Occur?
In read-end collisions there is a cause and effect
relationship during whiplash injuries that can cause damage to the
temporomandibular joints. There is a sudden impact in which the head
can snap in multi-directional planes. This happens so quickly that the
neck muscles never have a chance to relax; thus they anchor and hold the
jaw still. As the head is forced backwards by the impact, the mouth
will excessively open and hyper extend. This leads to tearing of the
muscles and supporting ligaments within the temporomandibular joints,
resulting in scar formation, neurogenic and muscular pain and edema.
This can also occur from other sources of trauma. As an example a blow
to the jaw from a fight can push the jaw back, tearing the restraining
ligaments, as can a fall, contact sprorts (football, hockey) especially
which a chin strap is utilized.
Aside from direct TMJ problems and internal
derangements within the joint there is a high incidence of injury to the
other supporting structures of the jaw, most notably the stylomandibular
ligament. This ligament originates just behind the ear and then
attaches to the back side of the jaw bone at t he level of the ear lobe.
Its function is to limit jaw motion. During a traumatic injury, such as
a blow to the head, a fall or in a whiplast-type injury this ligament
can be stretched beyond its physiological adaptive point. Often impact
and traumatic injuries can cause internal derangements of the
temporomandibular joints and pain syndromes in associated structures.
How is TMJ Diagnosed and Documented?
Diagnosis can be made after a through clinical and
physical examination including radiographic surveys. There may exist
the need for diagnostic anesthetic blockage and trigger pint injections
to quickly isolate the problematic areas. Documentation can be made
with CT scans, dynamic MRI, Doppler studies, range of motion studies,
thermography and arthography. Dynamic MRI documentation has proved to
be an effective tool in visualization of the disc and its displacements
along with concurrent bony changes. It has the ability to get a
superior image of the temporomandibular joint including the disc and
other soft tissue.
How is the Temporomandibular Joint Treated?
Treatment should not be delayed once there has been
a diagnosis of temporomandibular joint injury. The treatment plan may
include construction of an orthopaedic repositioning appliance (bite
splint), moist heat therapy, trigger point injections, nutritional
counseling, myofunctional therapy, occlusal equilibration and other
physiotherapeutic and pharmacological modalities. The treatment is
directed towards orthopaedic realignment of the mandible to the skull,
stabilization of the right and left temporomandibular joints and
restoring them to their normal physiological function.
Treatment of injuries in the conservative phase
takes between four to nine months. If conservative treatment is not
successful surgical intervention would be initiated. This could include
new arthroscopic evaluation and treatment, traditional open surgery or
radiofrequency thermoneurolysis. Once the patient is pain-free and
functioning normally, restorative phase of treatement would begin. This
allows the patient to cease wearing the orthopaedic repositioning
appliance by replacing the space which the appliance occupies with
either crown and bridge restorations to build up the heights of the
teeth or orthodontic rehabilitation to raise the heights of the teeth.
Occlusal equilibration may also be necessary. This phase of treatment
varies from months to years.
Potential Long-term Implications:
Even with the best diagnostic techniques and
treatment many patients will have a residual disability due to the very
nature of this type of injury. The temporomandibular joint is a highly
innervated sensitive joint which has very complicated movements within
it leading itself to susceptibility for injury. When these problems
exist for an extended period of time acute pain can turn into chronic
pain with significant behavioral changes occurring leading to the need
for invervention for health care providers outside the area of
* This article is presented and copyrighted by The 'Lectric Law Library
and Dr. Steven E. Lerner & Associates (www.drlerner.com)