Original article
Published on 04/06/96
Dr.ssa Barbara Massi
English Translation by
Dr .Susan Eslambolchi
"Cervical whiplash" or the
extension-flexion injury is the most common cervical insult associated with motor vehicle
acceleration-deceleration accidents.
Whiplash is more common in rear-end collisions, but can occur with front or side impacts.
Interestingly enough, the amount of damage to a vehicle does not correlate to the damage
to the patient.
Similar injuries can also be sustained during skiing or horseback riding accidents.
Following a rear-end collision or sudden deceleration, a flexion-extension-type of trauma
takes place which is characterized by the contraction of the anterior cervical muscles.
The combined forward head, neck and shoulder girdle posture and the increased muscle
tension cause the head to move to a posterior elevated position with an anterior cervical
spine muscle contraction. This is done to maintain the horizontal leveling of the cranium
required for equilibrium.
The direct consequence is the beginning of an acute muscular spasm, which if left
untreated, can become chronic .
Injury sustained in whiplash results in persistence of the symptoms with intense muscle
spasm as well as a compounding effect of traumatic emotional stress.
Symptoms following motor vehicle accidents are usually delayed for hours, days, or longer.
The pain can radiate to the TMJ.
However, since this is a gradual process and may take weeks or months, the patient may not
always make the connection between the motor vehicle accident and subsequent TMJ pain. The
pathogenesis of post-MVA whiplash is related to the relationship of the mandible and the
cranium.
Following sudden accelerations and decelerations, there is a certain amount of delay in
mandibular movements as compared to the rest of the head.
The mandible may assume a distal position with stretching of the retrodiscal tissues and
possible compression of the meniscus.
Joint sound now present is due to a distalization of the condyle due to cranial elevation
along with a previous anterior position of the disc in the glenoid fossa.
The described mechanism acts negatively on the ligaments and on the articular capsule, the
external and inside pterygoid muscles the temporalis and the masseter.
The symptomatology of post-MVA whiplash can be variable depending on the presence of
pre-existing articular lesions or a simple case of joint overloading (such as altered
occlusal interferences). Symptoms can be temporary.
However, if the trauma acts directly on already compromised joints, the symptoms can be
more serious. In these situations it is not uncommon to observe the onset of condyle-disc
incoordinations with the presence of a mutual click or, more seriously of true articular
blocks for inside luxation of the meniscus.
The diagnosis of such problems has been made much easier with the help of functional
investigation of the masticatory apparatus particularly surface electromyography of the
masticatory and cervical muscles.
This examination allows better diagnosis and allows one to monitor muscle responses to
different modes of therapy.
The treatment of post-MVA whiplash presents a problem of notable complexity. The
multifactorial nature of this condition dictates a multidisciplinary approach including
medication for chronic pain, counseling, physical therapy, acupuncture, hypnosis, and
biofeedback.
The outcome of treatment depends on many factors: the amount of time that has passed since
the trauma, the existing conditions of the joints and the occlusion, the state of
morpho-functional equilibrium of the masticatory apparatus generally and of the occlusion
particularly.
The presence of existing cervical myopathy constitutes one of the more important obstacles
to the attainment of a good result. If this obstacle can be removed, the treatment is more
effective.
Spasm in the cervical musculature could lead to TMJ dysfunction and chronic headache.
In conclusion, when treating post-MVA whiplash, the resolution of the muscular spasms and
the correction of occlusal deviations is of utmost importance.
REFERENCE