Effect of injection of botulinum toxin on lateral pterygoid muscle used together with the arthroscopy in patients with anterior disk displacement of the temporomandibular joint.

OBJECTIVES

In this study, we aimed to study the effects of an additional lateral pterygoid muscle (LPM), botulinum toxin-A (BTX-A) injection on arthroscopic lysis, lavage and posterior band coagulations. Subjective and objective measures have been documented.

PATIENTS AND METHODS

Fourty-three subjects (6 females, 37 males; mean age 35 years; range 15 to 48 years) with 52 joints were enrolled in the study. Patients were divided into two groups. The first group was treated with arthroscopic lysis, lavage and posterior band coagulation. The second group received an injection of 20 U of BTX-A to the LPM in addition to the former treatment. Patients were assessed statistically in the 1st week, and in the 1st, 3rd and 6th months postoperatively with the measures of lateral deviations, protrusions and visual analogue scale (VAS) values using Student-t test.

RESULTS

Group 1 and group 2 showed significant results within themselves with the exception of the 3rd month values of right deviations in group 1. When groups were compared with each other; significant results were observed in left deviation values only in the 3rd month, protrusion in the 1st month, and most importantly VAS values starting from the 1st month.

CONCLUSION

Botulinum toxin-A injection to the LPM mostly improved subjective measures starting from the 1st month. Other objective measures like protrusions, and deviations were not found to be affected generally. These findings suggest the improvement of symptoms with BTX-A injections in additon to the standard arthroscopy. However, diminishing effect of BTX-A and lack of information on the exact mechanism of action of toxin on temporomandibular joint necessitate further studies on this topic.