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Ultrastructural changes in human masseter muscles after botulinum neurotoxin a injection
Fushun Ma1, Zhaohui Zhai1, Shunwen Zhu1
1Plastic Surgery Hospital of Weifang Medical University, 288 Shenglidongjie Kuiwen Weifang, Shandong, People's Republic of China, 261042.
Introduction:
Botulinum neurotoxin A (BoNTA) has long been used as a therapeutic agent and has been widely accepted as a cosmetic agent in recent years. It can inhibit function and induce structural changes in skeletal muscle.
Methods:
Specimens of fresh dissected human masseter muscle were used to observe the ultrastructural changes that occurred at 6 and 12 months following BoNTA injection.
Results:
The findings observed were muscle fiber distortion, sarcomere shortening, mitochondrial vacuolar degeneration, glycogen accumulation, and H and M band disruption in the triad of tubules. At 12 months after injection, there was still evidence of degenerative changes in muscle ultrastructure, whereas most organelles exhibited a normal structure.
Discussion:
Profound ultrastructural and organelle disfiguring changes were observed after BoNTA injection into human masseter muscle. Most changes were transient, however, and were resolved by 12 months after injection. Muscle Nerve 57: 96-99, 2018.
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