Fig. 7
From: Application of botulinum toxin in maxillofacial field: part I. Bruxism and square jaw
Picture in the left is before the injection, picture in the middle is after 6 months of injection, and picture in the right is after 12 months of injection. The therapeutic effect was greatest at 6th month, and even though there was a bit of regression phenomenon at 12 month compared with the initial picture one can able to continuously observe contraction of the masseteric muscle. It is possible to determine the timing of the second injection.