Botulinum toxin for the treatment of temporomandibular joint disk disfigurement: clinical experience.

Type A botulinum toxin was used for the treatment of symptoms of 26 patients (40 joints) with temporomandibular joint disk disfigurement. In all patients, 0.5 ml (12.5 U) was injected into the lateral pterygoid muscle. The temporalis, medial pterygoid, and masseter muscles were injected if severe tenderness was noted. The data were compared using the Wilcoxon signed rank test and the McNemar test. With the exception of clicking of the right joint, all mean outcome measures showed a significant difference between the preinjection and postinjection assessments. There was a significant difference between the preinjection and postinjection pain scores of the right joint (P=0.0019) and the left joint (P=0.000). Postinjection values of the mouth opening (P=0.002), subjective functional dysfunction (P=0.065), and clicking of the left joint (P=0.001) also showed a statistically significant difference from the preinjection values. In addition, the severity and frequency of headache were reduced after botulinum toxin-A injection into the lateral pterygoid muscle.