Temporomandibular disorders: a clinical updateBMJ 1998; 317 doi: https://doi.org/10.1136/bmj.317.7152.190 (Published 18 July 1998) Cite this as: BMJ 1998;317:190
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The author did not discuss one important and potentially treatable cause of this clinical picture. Excessive muscle activity sometimes underlies `temporomandibular' disorders. It may arise in a range of conditions from focal jaw opening or closing dystonias, commonly drug-induced, to psychogenic clenching. Botulinum toxin A (BtA) injections can produce prolonged controlled weakness of the overactive muscles and in suitable patients can be very successful(2). BtA injections can generally be repeated as and when necessary, commonly every three months.
Injection into masseter and temporalis muscles will reduce the power of jaw-clenching, often relieving muscle spasms and hypertrophy, pain and involuntary (and possibly in subconscious) clenching. Jaw opening spasms may respond to injections into the pterygoid muscles. For instance, we have used this technique to block recurrent dislocation of the jaw from tardive dystonia, with relief lasting up to a year from a single injection session(3).
We suggest that when muscle overactivity is prominent BtA is considered before surgery is undertaken, particularly as surgery has a low long-term success rate(4)
1. George Dimitroulis. Temporomandibular disorders: a clinical update BMJ 1998;317:190-4.
2. Brin MF, Blitzer A, Herman S, Stewart C. Oro-facio-mandibular and lingual dystonia. In: Moore AP, ed. Handbook of botulinum toxin treatment. 1st ed. Oxford: Blackwell Scientific, 1995.
3. Moore AP, Wood GD. Medical management of recurrent temporomandibular joint dislocation using botulinum toxin A.
Br. Dent. J. 1997;183:415-417.
4. Juniper R. Whither the treatment of the TMJ?
Brit. J. Oral Surgery 1993;31:137-138.
Dr AP Moore,
Senior Lecturer in Clinical Neurology
The Walton Centre for Neurology and Neurosurgery
Liverpool L9 7LJ
Mr GD Wood
Wirral Hospitals Trust
Arrowe Park Hospital,
Competing interests: No competing interests