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Guignardat JF, Raoul G, Ferri J, Sciote JJ, Nicot R. Systematic review of the histological and functional effects of botulinum toxin A on masticatory muscles: Consideration in dentofacial orthopedics and orthognathic surgery. Ann Anat 2024; 256:152302. [PMID: 39038690 DOI: 10.1016/j.aanat.2024.152302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Revised: 05/31/2024] [Accepted: 07/03/2024] [Indexed: 07/24/2024]
Abstract
INTRODUCTION Botulinum toxin type A causes muscle paralysis and is widely used in the masticatory muscle for stomatognathic diseases, such as temporomandibular disorder, bruxism, or masseteric hypertrophy. Nonetheless, its muscular effect remains unclear. Better understanding could aid improved use and perhaps new indications, particularly in dentofacial orthopaedics and orthognathic surgery. METHODS This systematic review explored the histologic and functional effects of botulinum toxin in animal and human masticatory muscles and was conducted in accordance with the recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. The MEDLINE, Web of Science, and Cochrane Library electronic databases were searched for relevant articles. The inclusion criteria were human or animal masticatory muscle analysis after botulinum toxin injection(s) AND histological structural/ultrastructural analysis by optical or electronic microscopy OR functional effect analysis by bite force evaluation (occlusal force analyzer) and muscle activity (electromyography). RESULTS Of an initial 1578 articles, 44 studies were eventually included. Botulinum toxin injection in the masticatory muscle altered its histological structure and functional properties. The human and animal studies revealed ultrastructural change, atrophy, and fiber type modifications of the masticatory muscles after one injection. Botulinum toxin decreased bite force and muscle activity, but recovery was uncertain. CONCLUSIONS Muscle forces applied on the skeleton is a key feature of facial growth. Masticatory muscle paralysis changes mechanical stress on bones, which rebalances the force applied on facial bones. This new balance could benefit dental deformity or surgical relapse. Therefore, botulinum toxin could limit the orthognathic effect of the masticatory muscles in such patients. Given the uncertain recovery, multiple injections should be avoided, and usage should not deviate from established consensus.
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Affiliation(s)
| | - Gwénaël Raoul
- Univ. Lille, Inserm, CHU Lille, U1008 - Advanced Drug Delivery Systems, Department of Oral and Maxillofacial Surgery, F-59000 Lille, France
| | - Joël Ferri
- Univ. Lille, Inserm, CHU Lille, U1008 - Advanced Drug Delivery Systems, Department of Oral and Maxillofacial Surgery, F-59000 Lille, France
| | - James J Sciote
- Department of Orthodontics, Temple University, Philadelphia, Pennsylvania, USA
| | - Romain Nicot
- Univ. Lille, Inserm, CHU Lille, U1008 - Advanced Drug Delivery Systems, Department of Oral and Maxillofacial Surgery, F-59000 Lille, France.
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Nicot R, Raoul G, Vieira AR, Ferri J, Sciote JJ. ACTN3 genotype influences masseter muscle characteristics and self-reported bruxism. Oral Dis 2023; 29:232-244. [PMID: 34773324 PMCID: PMC9098697 DOI: 10.1111/odi.14075] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 10/12/2021] [Accepted: 11/10/2021] [Indexed: 01/03/2023]
Abstract
OBJECTIVES Main aim of the study was to explore the association between genetic polymorphisms in ACTN3 and bruxism. Secondary objectives included masseter muscle phenotypes assessment between bruxers and non-bruxers and according to genetic polymorphisms in ACTN3. MATERIALS AND METHODS Fifty-four patients undergoing orthognathic surgery for correction of their malocclusion were enrolled. Self-reported bruxism and temporomandibular disorders status were preoperatively recorded. Saliva samples were used for ACTN3 genotyping. Masseter muscle samples were collected bilaterally at the time of orthognathic surgery to explore the muscle fiber characteristics. RESULTS There were significant differences in genotypes for rs1815739 (R577X nonsense) (p = 0.001), rs1671064 (Q523R missense) (p = 0.005), and rs678397 (intronic variant) (p = 0.001) between bruxers and non-bruxers. Patients with self-reported bruxism presented a larger mean fiber area for types IIA (p = 0.035). The mean fiber areas in individuals with the wild-type CC genotype for rs1815739 (R577X) were significantly larger for type IIA fibers (1394.33 μm2 [572.77 μm2 ]) than in those with the TC and TT genotypes (832.61 μm2 [602.43 μm2 ] and 526.58 μm2 [432.21 μm2 ] [p = 0.014]). Similar results for Q523R missense and intronic variants. CONCLUSIONS ACTN3 genotypes influence self-reported bruxism in patients with dentofacial deformity through specific masseter muscle fiber characteristics.
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Affiliation(s)
- Romain Nicot
- Department of Oral and Maxillofacial Surgery, University of Lille, CHU Lille, INSERM U 1008: Controlled Drug Delivery Systems and Biomaterials, Lille, France
| | - Gwénaël Raoul
- Department of Oral and Maxillofacial Surgery, University of Lille, CHU Lille, INSERM U 1008: Controlled Drug Delivery Systems and Biomaterials, Lille, France
| | - Alexandre R. Vieira
- Department of Oral Biology, University of Pittsburgh School of Dental Medicine, Pittsburgh, Pennsylvania, USA
| | - Joël Ferri
- Department of Oral and Maxillofacial Surgery, University of Lille, CHU Lille, INSERM U 1008: Controlled Drug Delivery Systems and Biomaterials, Lille, France
| | - James J. Sciote
- Department of Orthodontics, Temple University, Philadelphia, Pennsylvania, USA
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Herring SW, Liu ZJ, Rafferty KL, Baldwin MC, Salamati A, Cunningham C, Owart B, Tamasas B. Repeated botulinum treatment of rabbit masseter causes cumulative tissue damage. Arch Oral Biol 2022; 141:105480. [PMID: 35724521 DOI: 10.1016/j.archoralbio.2022.105480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 05/30/2022] [Accepted: 06/08/2022] [Indexed: 11/29/2022]
Abstract
OBJECTIVE Botulinum neurotoxins (BoNT) are used in masticatory muscles for pain relief, unloading of the mandible, and cosmetic facial contouring. Treatment is often repeated every few months as function returns. This study assessed masticatory function and musculoskeletal structure after multiple BoNT treatment of the rabbit masseter. DESIGN Female rabbits received 3 injections of BoNT (n = 13) or saline (n = 5) into one masseter muscle at intervals of 12 weeks. The contralateral side served as control. Periodic measurements of masticatory electromyography (EMG) and stimulated anterior bite force were made. After the final 12-week recovery interval, neuromuscular connection was investigated by stimulating the masseteric nerve to elicit an evoked EMG response. Mandibular specimens were collected for microCT analysis, and masseters were collected for histomorphometry and counts of replicating cells. RESULTS Control and saline-injected muscles maintained consistent masticatory EMG and anterior bite force throughout the study. BoNT-injected masseters showed strong declines after each injection; during the 12-week recovery period, masticatory EMG and anterior bite force improved, although only electrical activity reached normal levels. Multiple injection resulted in persistently atrophied muscle fibers with fibrosis, and notable loss of bone from the mandibular body and condyle. The uninjected masseters of the BoNT group also showed evidence of mild toxin-related changes. CONCLUSIONS Although muscle function is mostly regained after each injection, masseters receiving multiple doses of BoNT show extensive damage. In addition, mandibular bone density is decreased on the injected side.
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Affiliation(s)
- Susan W Herring
- Department of Orthodontics, University of Washington, Seattle, WA 98195, USA.
| | - Zi-Jun Liu
- Department of Orthodontics, University of Washington, Seattle, WA 98195, USA.
| | | | - Michael C Baldwin
- Department of Oral Health Sciences, University of Washington, Seattle, WA 98195, USA.
| | - Atriya Salamati
- Department of Oral Health Sciences, University of Washington, Seattle, WA 98195, USA.
| | - Cambria Cunningham
- Department of Orthodontics, University of Washington, Seattle, WA 98195, USA.
| | - Birkin Owart
- Department of Orthodontics, University of Washington, Seattle, WA 98195, USA.
| | - Basma Tamasas
- Department of Oral Health Sciences, University of Washington, Seattle, WA 98195, USA.
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Baldwin MC, Liu ZJ, Rafferty KL, Keith A, Tamasas B, Kaiyala K, Herring SW. Botulinum toxin in the masseter muscle: Lingering effects of denervation. Anat Rec (Hoboken) 2021; 305:1215-1230. [PMID: 34486243 DOI: 10.1002/ar.24756] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2021] [Revised: 06/17/2021] [Accepted: 07/14/2021] [Indexed: 12/28/2022]
Abstract
Botulinum neurotoxins (BoNTs) are paralytic agents used to treat a variety of conditions in jaw muscles. Although their effect is considered temporary, there are reports of persistent functional changes. Using rabbits that received BoNT injection in one masseter muscle, the recovery of neuromuscular connection was investigated using nerve stimulation to evoke an electromyographic (EMG) response, and the recovery of muscle fibers was investigated using histological morphometry and bromodeoxyuridine (BrdU) immunohistochemistry. One month after treatment, evoked EMG was greatly reduced in both amplitude and duration, indicating that little reinnervation had taken place. Muscle fibers were atrophied and collagenous tissue was increased. Three months after treatment, evoked EMG duration was normal, indicating that at least some neuromuscular junctions were functional. Histologically, some muscle fibers were hypertrophied, some were still atrophied, and some appeared to have died. Fibrosis was still apparent amid slight increases in dividing cells and regenerating fibers. The histological effects of BoNT were evident although attenuated at a distance of about 1 cm from the injection level, but no regional differences could be discerned for the evoked EMGs. In conclusion, there were persistent muscular deficits seen 3 months after BoNT treatment that may have been caused by the failure of some affected muscle fibers to become reinnervated.
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Affiliation(s)
- Michael C Baldwin
- Department of Oral Health Sciences, University of Washington, Seattle, Washington, USA
| | - Zi Jun Liu
- Department of Orthodontics, University of Washington, Seattle, Washington, USA
| | | | - Andrew Keith
- Department of Orthodontics, University of Washington, Seattle, Washington, USA
| | - Basma Tamasas
- Department of Oral Health Sciences, University of Washington, Seattle, Washington, USA.,Department of Orthodontics, Boston University, Boston, MA, USA
| | - Karl Kaiyala
- Department of Oral Health Sciences, University of Washington, Seattle, Washington, USA
| | - Susan W Herring
- Department of Orthodontics, University of Washington, Seattle, Washington, USA
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Effect of Botulinum Toxin Type A on Mandibular Fracture Healing: An Experimental Study in Rabbits. J Oral Maxillofac Surg 2020; 78:2281.e1-2281.e8. [PMID: 32652049 DOI: 10.1016/j.joms.2020.06.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Revised: 05/11/2020] [Accepted: 06/04/2020] [Indexed: 11/23/2022]
Abstract
PURPOSE The effect of botulinum toxin type A (BTX-A) on fracture healing of the long bones is controversial, and no controlled clinical or experimental study has investigated the effect of BTX-A on mandibular fractures. The purpose of this study was to investigate whether BTX-A injection into the masseter muscles affects bone healing by reducing the displacing forces in an unfavorable mandibular fracture model. MATERIALS AND METHODS Forty-eight male New Zealand white rabbits were used. Ten units of BTX-A was injected into each masseter muscle in the animals in the BTX-A group, whereas saline solution was injected in the animals in the control group. A unilateral osteotomy and fixation with a microplate were performed. Bone healing was evaluated by radiodensitometric, biomechanical, histologic, and histomorphometric methods after 21 days. RESULTS The mean bone mineral density in the fracture area was significantly higher in the BTX-A group (P = .038). The mean failure load and bending modulus values were significantly higher in the BTX-A group than in the control group (P = .032 and P = .005, respectively). The mean histologic bone healing scores, bone volume-total volume values, and trabecular diameter values were significantly higher in the BTX-A group than in the control group (P = .001, P = .001, and P = .026, respectively). CONCLUSIONS BTX-A application into the masseter muscles improves bone healing of a unilateral mandibular fracture in rabbits.
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Olson RM, Mokhtarzadeh A, McLoon LK, Harrison AR. Effects of Repeated Eyelid Injections with Botulinum Toxin A on Innervation of Treated Muscles in Patients with Blepharospasm. Curr Eye Res 2018; 44:257-263. [PMID: 30380945 DOI: 10.1080/02713683.2018.1543707] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
PURPOSE To assess changes in innervation and muscle morphology after repeated botulinum toxin A injections in subjects with benign essential blepharospasm. METHODS Surgical waste specimens were processed for histologic examination of nerve fibers, neuromuscular junctions, fiber size, and central nucleation and compared to age matched controls and to two subjects with blepharospasm that had not received botulinum toxin A injections. RESULTS There was a significant increase in amount of nerve fibers and numbers of neuromuscular junctions in the orbicularis oculi muscles from subjects with blepharospasm treated repetitively with botulinum toxin A. In addition there was a significant decrease in mean muscle fiber cross-sectional area and an increase in central nucleation. The specimens from the subjects with only blepharospasm had the same density of nerves but had intermediate levels of neuromuscular junctions. CONCLUSIONS These data suggest that repeated injections of botulinum toxin A has an effect on nerve and neuromuscular junction numbers, which are partly mirrored in orbicularis oculi muscle from subjects with blepharospasm only. These studies suggest the potential for modulating these changes in order to extend the duration of effectiveness of botulinum toxin.
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Affiliation(s)
- Rose M Olson
- a Department of Ophthalmology and Visual Neurosciences , University of Minnesota , Minneapolis , Minnesota , USA
| | - Ali Mokhtarzadeh
- a Department of Ophthalmology and Visual Neurosciences , University of Minnesota , Minneapolis , Minnesota , USA
| | - Linda K McLoon
- a Department of Ophthalmology and Visual Neurosciences , University of Minnesota , Minneapolis , Minnesota , USA.,b Department of Neuroscience , University of Minnesota , Minneapolis , Minnesota , USA
| | - Andrew R Harrison
- a Department of Ophthalmology and Visual Neurosciences , University of Minnesota , Minneapolis , Minnesota , USA.,c Department of Otolaryngology , University of Minnesota , Minneapolis , Minnesota , USA
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Nagi R, Patil DJ, Sahu S, Jain S, Naidu GS. Botulinum toxin in the management of head and neck disorders. Oral Surg Oral Med Oral Pathol Oral Radiol 2016; 123:419-428. [PMID: 28159584 DOI: 10.1016/j.oooo.2016.11.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Revised: 11/14/2016] [Accepted: 11/25/2016] [Indexed: 11/26/2022]
Abstract
Botulinum toxin is a polypeptide protoxin synthesized by Clostridium botulinum that results in localized reduction of muscle activity by inhibiting acetylcholine release at the neuromuscular junction. In 2004, the US Food and Drug Administration approved its application in the treatment of various medical conditions, such as facial wrinkles, strabismus, cervical dystonia, blepharospasm, and hyperhidrosis. Later, its application extended to improving dental esthetics and gummy smile. It was found to be a safe and effective alternative to medical therapy to treat various head and neck disorders that have a neurologic component. In this review, we will highlight the mechanism of action and therapeutic benefits of botulinum toxin in the management of head and neck disorders.
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Affiliation(s)
- Ravleen Nagi
- Department of Oral Medicine and Radiology, New Horizon Dental College and Research Institute, Sakri, Bilaspur, India.
| | - Deepa Jatti Patil
- Department of Oral Medicine and Radiology, Swami Devi Dyal Dental College, Panchkula, Haryana, India
| | - Shashikant Sahu
- Burn and Trauma Centre, Department of Plastic Surgery, Bilaspur, Chhattisgarh, India
| | - Supreet Jain
- Department of Oral Medicine and Radiology, New Horizon Dental College and Research Institute, Sakri, Bilaspur, India
| | - Giridhar S Naidu
- Department of Oral Medicine and Radiology, New Horizon Dental College and Research Institute, Sakri, Bilaspur, India
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9
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Authors' response. Am J Orthod Dentofacial Orthop 2016; 149:443-5. [DOI: 10.1016/j.ajodo.2016.01.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Revised: 01/21/2016] [Accepted: 01/21/2016] [Indexed: 01/09/2023]
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Pihut M, Ferendiuk E, Szewczyk M, Kasprzyk K, Wieckiewicz M. The efficiency of botulinum toxin type A for the treatment of masseter muscle pain in patients with temporomandibular joint dysfunction and tension-type headache. J Headache Pain 2016; 17:29. [PMID: 27011213 PMCID: PMC4807183 DOI: 10.1186/s10194-016-0621-1] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Accepted: 03/18/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Temporomandibular joint dysfunction are often accompanied by symptoms of headache such as tension-type headache which is the most frequent spontaneous primary headache. Masseter muscle pain is commonly reported in this group. The purpose of the study was to assess the efficiency of intramuscular botulinum toxin type A injections for treating masseter muscle pain in patients with temporomandibular joint dysfunction and tension-type headache. METHODS This prospective outcome study consisted of 42 subjects of both genders aged 19-48 years diagnosed with masseter muscle pain related to temporomandibular joint dysfunction and tension-type headache. The subjects were treated by the intramuscular injection of 21 U (mice units) of botulinum toxin type A (Botox, Allergan) in the area of the greatest cross-section surface of both masseter bellies. Pain intensity was evaluated using visual analogue scale (VAS) and verbal numerical rating scale (VNRS) 1 week before the treatment and 24 weeks after the treatment. The obtained data were analyzed using the Wilcoxon matched pairs test (p ≤ 0,005). RESULTS The results of this study showed a decrease in the number of referred pain episodes including a decrease in pain in the temporal region bilaterally, a reduction of analgesic drugs intake as well as a decrease in reported values of VAS and VNRS after injections (p = 0,000). CONCLUSIONS The intramuscular botulinum toxin type A injections have been an efficient method of treatment for masseter muscle pain in patients with temporomandibular joint dysfunction and tension-type headache.
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Affiliation(s)
- Malgorzata Pihut
- Department of Dental Prosthetics, Jagiellonian University in Krakow, College of Medicine, Institute of Dentistry, 4 Montelupich St., 31-155, Krakow, Poland
| | - Ewa Ferendiuk
- Department of Dental Prosthetics, Jagiellonian University in Krakow, College of Medicine, Institute of Dentistry, 4 Montelupich St., 31-155, Krakow, Poland
| | - Michal Szewczyk
- Department of Dental Prosthetics, Jagiellonian University in Krakow, College of Medicine, Institute of Dentistry, 4 Montelupich St., 31-155, Krakow, Poland
| | - Katarzyna Kasprzyk
- Department of Neurology, Jagiellonian University in Krakow, College of Medicine, 3 Botaniczna St., 31-503, Krakow, Poland
| | - Mieszko Wieckiewicz
- Department of Prosthetic Dentistry, Faculty of Dentistry, Wroclaw Medical University, 26 Krakowska St., 50-425, Wroclaw, Poland.
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Korfage J, Kwee K, Everts V, Langenbach G. Myosin Heavy Chain Expression Can Vary over the Length of Jaw and Leg Muscles. Cells Tissues Organs 2016; 201:130-7. [PMID: 26950765 PMCID: PMC5296893 DOI: 10.1159/000443606] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 12/21/2015] [Accepted: 12/21/2015] [Indexed: 11/19/2022] Open
Abstract
Muscle fiber type classification can be determined by its myosin heavy chain (MyHC) composition based on a few consecutive sections. It is generally assumed that the MyHC expression of a muscle fiber is the same over its length since neural stimulation and systemic influences are supposed to be the same over its length. We analyzed this in detail in three muscle types: the temporalis (closer) and digastricus (opener; both first brachial arch), and the medial gastrocnemius (somite). Sections of the muscles were incubated with monoclonal antibodies against various MyHC isoforms, and the distribution of these isoforms within individual fibers was followed over a distance of approximately 1 mm. The staining intensity of a fiber was measured and compared with the other fibers in the section. In the temporalis, digastricus, and gastrocnemius, 46, 11, and 15%, respectively, of their MyHC-I fibers showed a variation in the staining intensity over the length of their fibers, as well as 47, 87, and 22%, respectively, of their MyHC-IIA fibers. Most variable fibers were found amongst those with an overall relative intermediate staining intensity, which are presumably hybrid fibers. We conclude that different parts of a muscle fiber can have different fiber type compositions and, thus, contractile properties. Some muscle parts might reach their maximum contraction peak sooner or later than a muscle part a few microns further away. Next to stimulation by the nerve and systemic influences, local influences might also have an impact on the MyHC expression of the fiber.
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Affiliation(s)
- J.A.M. Korfage
- Department of Functional Anatomy and Oral Cell Biology, Academisch Centrum Tandheelkunde Amsterdam, Amsterdam, The Netherlands
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Park SY, Park YW, Ji YJ, Park SW, Kim SG. Effects of a botulinum toxin type A injection on the masseter muscle: An animal model study. Maxillofac Plast Reconstr Surg 2015; 37:10. [PMID: 25938091 PMCID: PMC4407284 DOI: 10.1186/s40902-015-0010-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2015] [Accepted: 02/16/2015] [Indexed: 11/10/2022] Open
Abstract
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.
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Affiliation(s)
- Si-Yeok Park
- Department of Oral and Maxillofacial Surgery, College of Dentistry, Gangneung-Wonju National University, Gangneung, Republic of Korea
| | - Young-Wook Park
- Department of Oral and Maxillofacial Surgery, College of Dentistry, Gangneung-Wonju National University, Gangneung, Republic of Korea
| | - Young-Jun Ji
- Department of Biomedical Engineering, Ulsan University, Ulsan, Republic of Korea
| | - Sung-Wook Park
- Department of Electronic Engineering, Gangneung-Wonju National University, Gangneung, Republic of Korea
| | - Seong-Gon Kim
- Department of Oral and Maxillofacial Surgery, College of Dentistry, Gangneung-Wonju National University, Gangneung, Republic of Korea.,Oral and Maxillofacial Surgery, Gangneung-Wonju National University-College of Dentistry, Gangneung, 210-702 Republic of Korea
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Killian ML, Lim CT, Thomopoulos S, Charlton N, Kim HM, Galatz LM. The effect of unloading on gene expression of healthy and injured rotator cuffs. J Orthop Res 2013; 31:1240-8. [PMID: 23508698 PMCID: PMC3690165 DOI: 10.1002/jor.22345] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2012] [Accepted: 02/12/2013] [Indexed: 02/04/2023]
Abstract
Tendon unloading following rupture of one of the rotator cuff tendons can induce alterations in muscle physiology and tendon structure, which can subsequently affect reparability and healing potential. Yet little is known about the effects of muscle and tendon unloading on the molecular response of the rotator cuff. We determined the effect of mechanical unloading on gene expression and morphology of healthy supraspinatus tendons and muscles, and the same muscles after acute injury and repair. Mechanical unloading was achieved by tenotomy and/or botulinum toxin A (BTX) chemical denervation in a rat rotator cuff model of injury and repair. Gene expression profiles varied across regions of the muscle, with the greatest changes seen in the distal aspect of the muscle for most genes. Myogenic and adipogenic genes were upregulated in muscle when unloaded (tenotomy and BTX). Tendon injury, with and without repair, resulted in upregulation of fibrosis- and tendon-specific gene expression. The expression of scleraxis, a transcription factor necessary for tendon development, was upregulated in response to injury and repair. In summary, tendon detachment and repair had the greatest effect on tendon gene expression, while unloading had the greatest effect on muscle gene expression.
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Affiliation(s)
- ML Killian
- Department of Orthopaedic Surgery, Washington University, St Louis, MO
| | - CT Lim
- Department of Orthopaedic Surgery, Sung-Ji Hospital, Gangwon-do, South Korea
| | - S Thomopoulos
- Department of Orthopaedic Surgery, Washington University, St Louis, MO
| | - N Charlton
- Department of Orthopaedic Surgery, Washington University, St Louis, MO
| | - HM Kim
- Department of Orthopaedic Surgery, Penn State University Hershey, Hershey, PA
| | - LM Galatz
- Department of Orthopaedic Surgery, Washington University, St Louis, MO
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