A Possible Dental Connection for Spasmodic Torticollis
A Possible Dental Connection for Spasmodic Torticollis
Anthony B. Sims DDS
Spasmodic torticollis, the most common form of focal dystonia, is characterized by abnormal muscle contractions in the head and neck area. Sustained muscle contractions result in abnormal positions or posturing. The dystonic muscle spasms associated with spasmodic torticollis may affect any combination of neck muscles. It is characterized by abnormal squeezing and twisting muscle contractions in the head and neck area. These sustained muscle contractions or spasms result in jerky head movements or periodic or sustained unnatural positioning the head. Torticollis (rotated head position) results in different forms such as Retrocollis (head pulled backward), Anteriocollis (head pulled forward), and Laterocollis (head pulled to the side.) Combinations of these forms can also develop. Recent reports have suggested functional interactions between the masticatory and head motor systems.
The coordination of rhythmic movements of jaw and head motor systems has been reported in both animal models and humans. Recently, it was also observed that reflex activities and tonic responses in neck muscles could be elicited by periodontal mechanical stimulation. These reports suggest that the dental nerve can produce head movements or modify the neck muscle tone in addition to the regulation of jaw movements. There is growing clinical evidence that the temporomandibular joint (TMJ) dysfunction may produce similar neurological and/or painful symptoms when it coexists.
Studies have indicated that electrical stimulation of dental nerve branches can produce excitation of neck motor nerves. Although this stimulation was not necessarily painful the reflex responses were regarded to be of a protective nature. Some studies also suggest that focal dystonia may be precipitated by trauma or overuse of the affected region of the body. In some cases, the relationship between trauma and the onset of dystonia is clear when dystonia follows brain injury or severe peripheral trauma. However, in many patients, the relationship is less clear and trauma alone probably would not be sufficient for the development of dystonia. Rather, some research suggests that trauma may play some role in triggering dystonia in those with previously, very mild, undetectable cases-or in patients with an existing, potentially genetic, susceptibility to the disorder. One of these areas is within the TMJ.
There are many studies, which link dysfunction of the TMJ/TMD to multiple symptoms including but not limited to tinnitus, decreased hearing, headaches, dizziness, difficulty balancing, difficulty swallowing, neck and shoulder soreness, cracking & clicking sounds in the jaw joints, limited mouth opening, visual disturbances and in some cases neurological disorders. Many of these sources also cite cervical spine dysfunction [CSD] as being a contributing and correlating factor in TMD. The close relationship of TMD to CSD warrants close scrutiny and certainly collaboration between physicians, dentists, and physical therapists or chiropractors experienced in upper cervical analysis and adjustment and dentists experienced in TMD.
The most common cause of neck pain results from weakened muscles and poor posture. . One area that has not been totally explored is the aspect of peripheral nerve trauma. It is suspected that certain kinds of peripheral nerve injuries can degrade or alter sensory nerve transmissions into the brain in such a way as to trigger unwanted muscle actions. Injury to the jaw, temporomandibular joint, or muscles of the head and neck – such as from a heavy blow or whiplash – can cause TMD. Other possible causes include:
-Grinding or clenching the teeth, which puts a lot of pressure on the TMJ
-Dislocation of the soft cushion or disc between the ball and socket in the jaw joint
-Presence of osteoarthritis or rheumatoid arthritis in the TMJ
-Stress, which can cause a person to tighten facial and jaw muscles or clench the teeth
The dental nerve that innervates the jaw muscles and TMJ also commingles with the nerves of the neck. Therefore dysfunction within cervical structures commonly leads to problems within the jaw and vice versa.
Most treatments are aimed at restoring normal anatomy, encouraging normal range of motion of the joints and muscles within the neck and decreasing or eliminating all aggravating factors. Research has shown that when one of the branches of the dental nerve in the TMJ is stimulated, there is motor activity in the sternocleidomastoid and muscles of the neck. This stimulus travels via the dental nerve to the brainstem and activates them. Within this area of the brainstem are nerves that when stimulated cause the head and neck muscles to turn. The etiology for spasmodic torticollis may be that these brainstem nerves are being constantly bombarded by over stimulated nerves within the TMJ. With a constant stimulation of this dental nerve by some type of peripheral trauma or injury a bad signal may be causing the head and neck to turn. When the stimulus is relieved in the TMJ, the stimulus into the brainstem is also relieved, which then relieves the turning of the head.
This is accomplished with oral orthotics (mouthpieces) specifically made for each individual patient. Research is still going on in this field and very positive results are being made. A dentist that specializes in TMD may be able to possibly help discontinue the pain and symptoms associated with spasmodic torticollis. Trials are still being done in this field and continued research is needed. It is an alternative treatment for ST but the success rate is good for those with well-defined TMJ disorders. Significantly, treatment with TMJ orthotics is fully compatible with established treatments including botulinum toxin injections, muscle relaxants, baclofen injections for pain, and various kinds of physical therapy. Patients may find some combination of these treatments will provide maximum benefit and/or relief.
Dr. Sims’ work can be viewed at the following websites: absimsdds.com or bodymovementdisorders.com or thefifthnerve.com. His email address is firstname.lastname@example.org