Effects of a botulinum toxin type A injection on the masseter muscle: An animal model study.

BACKGROUND: The aim of this study was to investigate the effect of a botulinum toxin type A (BTX-A) injection in the masseter muscle using electromyography (EMG) in an animal model. METHODS: Ten male adult (>3 months of age) New Zealand white rabbits were used. Muscle activity was continuously recorded from 8 hours before to 8 hours after BTX-A injection. The rabbits received unilateral BTX-A injections of either 5 units (group 1, n = 5) or 20 units (group 2, n = 5). RESULTS: The masseter muscle activity of the rabbits was significantly reduced immediately after BTX-A injection (P < 0.05 for both groups). When the results from group 1 were compared with those from group 2, only the peak voltage was significantly decreased in group 2 (P = 0.013). CONCLUSION: Masseter muscle activity measured by EMG was immediately decreased after a BTX-A injection.

Defatting Vestibuloplasty for Functional and Esthetic Reconstruction of Tongue.

The radial forearm free flap (RFFF) is a thin and pliable tissue with many advantages for tongue reconstruction. However, tongues reconstructed with RFFF occasionally need revision surgery because inadequate defect measurement at primary surgery can lead to bulkiness and limited movement of reconstructed tongue. In this case, the patient underwent partial glossectomy and RFFF reconstruction for treatment of tongue cancer five years prior. We could not make a lower denture for the patient, because the alveolo-lingual sulcus of tongue was almost lost. So we performed vestibuloplasty with a modified Kazanjian method on the lingual vestibule of the mandibular right posterior area, and defatting surgery to debulk the flap. After surgery, we observed that the color and texture of the revised tongue changed to become similar with adjacent tissue. The patient obtained a more functional and esthetic outcome. Accordingly, we present a case report with a review of relevant literature.