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Li S, Mei L, Chen Q, Gao K, Zheng W, Li Y. Unilateral injection of botulinum toxin type A into the masseter muscle induces mandibular asymmetry in adolescent rats by suppressing the angular process growth. Am J Orthod Dentofacial Orthop 2024; 165:232-244. [PMID: 37897486 DOI: 10.1016/j.ajodo.2023.09.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2023] [Revised: 09/01/2023] [Accepted: 09/01/2023] [Indexed: 10/30/2023]
Abstract
INTRODUCTION Mandibular asymmetry has negative impacts on maxillofacial aesthetics and psychological well-being. This study investigated the effects of unilateral injection of botulinum toxin type A (BTX-A) into the masseter muscle on mandibular symmetry. METHODS Forty Wistar rats (4-week-old) were divided into 4 groups (n = 10): control, group 1 (1U BTX-A), group 2 (3U BTX-A), and group 3 (1U BTX-A for 3 times). BTX-A was injected into the right masseter of treatment groups. Cone-beam computerized tomography scans were taken before the injection and then at 2 weeks, 4 weeks, and 6 weeks after injection. Histologic and immunohistochemical staining were done for the condylar cartilage. RNA sequencing and quantitative reverse transcription polymerase chain reaction were used to detect gene expression in the angular process. RESULTS In Groups 2 and 3, the right angular process length and the ramus height were reduced 4 weeks after injection, resulting in the mandibular midline deviating to the right side; the right condylar cartilage had reduced thickness and decreased expression of RUNX2, SOX9, and COL II (P <0.05). Two hundred sixty-one genes were differentially expressed (256 downregulated) in the angular process at 3 days post-BTX-A injection, and the calcium signaling pathway was unveiled through the Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis. Furthermore, TRPC1, Wnt5a, CaMKII, Ctnnb1, and RUNX2 expression were significantly downregulated at 1 and 3 days postinjection. CONCLUSIONS Unilateral injection of BTX-A into the masseter muscle in adolescent rats induces mandibular asymmetry by suppressing the angular process growth on the injected side.
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Affiliation(s)
- Shijia Li
- State Key Laboratory of Oral Diseases, National Center for Stomatology, National Clinical Research Center for Oral Diseases, Department of Orthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Li Mei
- Discipline of Orthodontics, Department of Oral Sciences, Faculty of Dentistry, University of Otago, Dunedin, New Zealand
| | - Qiuyu Chen
- State Key Laboratory of Oral Diseases, National Center for Stomatology, National Clinical Research Center for Oral Diseases, Department of Oral and Maxillofacial Surgery, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Kui Gao
- State Key Laboratory of Oral Diseases, National Center for Stomatology, National Clinical Research Center for Oral Diseases, Department of Endodontics and Operative Dentistry, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Wei Zheng
- State Key Laboratory of Oral Diseases, National Center for Stomatology, National Clinical Research Center for Oral Diseases, Department of Oral and Maxillofacial Surgery, West China Hospital of Stomatology, Sichuan University, Chengdu, China.
| | - Yu Li
- State Key Laboratory of Oral Diseases, National Center for Stomatology, National Clinical Research Center for Oral Diseases, Department of Orthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, China.
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2
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Endo Y, Groom L, Wang SM, Pannia E, Griffiths NW, Van Gennip JLM, Ciruna B, Laporte J, Dirksen RT, Dowling JJ. Two zebrafish cacna1s loss-of-function variants provide models of mild and severe CACNA1S-related myopathy. Hum Mol Genet 2024; 33:254-269. [PMID: 37930228 PMCID: PMC10800018 DOI: 10.1093/hmg/ddad178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 09/25/2023] [Accepted: 10/09/2023] [Indexed: 11/07/2023] Open
Abstract
CACNA1S-related myopathy, due to pathogenic variants in the CACNA1S gene, is a recently described congenital muscle disease. Disease associated variants result in loss of gene expression and/or reduction of Cav1.1 protein stability. There is an incomplete understanding of the underlying disease pathomechanisms and no effective therapies are currently available. A barrier to the study of this myopathy is the lack of a suitable animal model that phenocopies key aspects of the disease. To address this barrier, we generated knockouts of the two zebrafish CACNA1S paralogs, cacna1sa and cacna1sb. Double knockout fish exhibit severe weakness and early death, and are characterized by the absence of Cav1.1 α1 subunit expression, abnormal triad structure, and impaired excitation-contraction coupling, thus mirroring the severe form of human CACNA1S-related myopathy. A double mutant (cacna1sa homozygous, cacna1sb heterozygote) exhibits normal development, but displays reduced body size, abnormal facial structure, and cores on muscle pathologic examination, thus phenocopying the mild form of human CACNA1S-related myopathy. In summary, we generated and characterized the first cacna1s zebrafish loss-of-function mutants, and show them to be faithful models of severe and mild forms of human CACNA1S-related myopathy suitable for future mechanistic studies and therapy development.
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Affiliation(s)
- Yukari Endo
- Program for Genetics and Genome Biology, Hospital for Sick Children, 686 Bay Street, Toronto, ON M5G 0A4, Canada
| | - Linda Groom
- Department of Pharmacology and Physiology, University of Rochester Medical Center, 601 Elmwood Ave, Rochester, NY 14642, United States
| | - Sabrina M Wang
- Program for Genetics and Genome Biology, Hospital for Sick Children, 686 Bay Street, Toronto, ON M5G 0A4, Canada
| | - Emanuela Pannia
- Program for Genetics and Genome Biology, Hospital for Sick Children, 686 Bay Street, Toronto, ON M5G 0A4, Canada
- Zebrafish Genetics and Disease Models Core Facility, Hospital for Sick Children, 686 Bay Street, Toronto, ON M5G 0A4, Canada
| | - Nigel W Griffiths
- Program in Developmental and Stem Cell Biology, Hospital for Sick Children, 686 Bay Street, Toronto, ON M5G 0A4, Canada
| | - Jenica L M Van Gennip
- Program in Developmental and Stem Cell Biology, Hospital for Sick Children, 686 Bay Street, Toronto, ON M5G 0A4, Canada
| | - Brian Ciruna
- Program in Developmental and Stem Cell Biology, Hospital for Sick Children, 686 Bay Street, Toronto, ON M5G 0A4, Canada
- Department of Molecular Genetics, University of Toronto, 1 King's College Circle, Toronto, ON M5S 1A8, Canada
| | - Jocelyn Laporte
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Inserm U1258, Cnrs UMR7104, Université de Strasbourg, 1 Rue Laurent Fries, Illkirch 67400, France
| | - Robert T Dirksen
- Department of Pharmacology and Physiology, University of Rochester Medical Center, 601 Elmwood Ave, Rochester, NY 14642, United States
| | - James J Dowling
- Program for Genetics and Genome Biology, Hospital for Sick Children, 686 Bay Street, Toronto, ON M5G 0A4, Canada
- Department of Molecular Genetics, University of Toronto, 1 King's College Circle, Toronto, ON M5S 1A8, Canada
- Division of Neurology, Hospital for Sick Children, 555 University Ave, Toronto, ON M5G 1X8, Canada
- Department of Paediatrics, University of Toronto, 555 University Ave, Toronto, ON M5G 1X8, Canada
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Dubied M, Montuire S, Navarro N. Functional constraints channel mandible shape ontogenies in rodents. ROYAL SOCIETY OPEN SCIENCE 2022; 9:220352. [PMID: 36300135 PMCID: PMC9579770 DOI: 10.1098/rsos.220352] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Accepted: 08/31/2022] [Indexed: 06/16/2023]
Abstract
In mammals, postnatal growth plays an essential role in the acquisition of the adult shape. During this period, the mandible undergoes many changing functional constraints, leading to spatialization of bone formation and remodelling to accommodate various dietary and behavioural changes. The interactions between the bone, muscles and teeth drive this developmental plasticity, which, in turn, could lead to convergences in the developmental processes constraining the directionality of ontogenies, their evolution and thus the adult shape variation. To test the importance of the interactions between tissues in shaping the ontogenetic trajectories, we compared the mandible shape at five postnatal stages on three rodents: the house mouse, the Mongolian gerbil and the golden hamster, using geometric morphometrics. After an early shape differentiation, by both longer gestation and allometric scaling in gerbils or early divergence of postnatal ontogeny in hamsters in comparison with the mouse, the ontogenetic trajectories appear more similar around weaning. The changes in muscle load associated with new food processing and new behaviours at weaning seem to impose similar physical constraints on the mandible, driving the convergences of the ontogeny at that stage despite an early anatomical differentiation. Nonetheless, mice present a rather different timing compared with gerbils or hamsters.
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Affiliation(s)
- Morgane Dubied
- Biogéosciences, UMR 6282 CNRS, EPHE, Université Bourgogne Franche-Comté, 6 bd Gabriel, 21000 Dijon, France
| | - Sophie Montuire
- Biogéosciences, UMR 6282 CNRS, EPHE, Université Bourgogne Franche-Comté, 6 bd Gabriel, 21000 Dijon, France
- EPHE, PSL University, 75014 Paris, France
| | - Nicolas Navarro
- Biogéosciences, UMR 6282 CNRS, EPHE, Université Bourgogne Franche-Comté, 6 bd Gabriel, 21000 Dijon, France
- EPHE, PSL University, 75014 Paris, France
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4
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Zou Y, Lin H, Cai J, Xie Q, Chen W, Lu YG, Xu L. Effects of functional mandibular lateral shift on craniofacial growth and development in growing rats. J Oral Rehabil 2022; 49:915-923. [PMID: 35583904 DOI: 10.1111/joor.13341] [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: 08/04/2021] [Revised: 03/29/2022] [Accepted: 05/09/2022] [Indexed: 11/26/2022]
Abstract
BACKGROUND Unilateral posterior crossbite, one of the most frequent malocclusions, is often associated with functional lateral shift of the mandible. Although the effects of functional lateral shift on the mandible and temporomandibular joint have been examined in various animal experiments, cranial and maxillary changes have received less attention. OBJECTIVE This study investigated the effects of functional lateral shift on the craniofacial complex in growing rats. METHODS Eighty 5-week-old male Sprague-Dawley rats were randomly. divided into an experimental group (n=40), which received an oblique guide appliance that shifted the mandible to the left during closure, and a control group (n=40). The rats were scanned by cone-beam computed tomography at 3 days and 1, 2, 4, and 8 weeks. The dimensions of the mandibular bone, condyle, maxilla and cranium were measured. RESULTS The mandibles of rats in the experimental group were smaller than those of the rats in the control group and were asymmetrical. The condyles of the rats in the experimental group were thinner than those of the control rats. The condylar length on the ipsilateral side was shorter and wider than that on the contralateral side from 4 to 8 weeks. No significant differences in cranial length or height were observed between the experimental and control groups. The height of the upper first molar and alveolar bone on the contralateral side was significantly smaller than that on the ipsilateral side and in the controls from 4 to 8 weeks. CONCLUSION Functional shift in the mandible produces morphological asymmetries in the mandible and maxillary region and may cause bilateral condylar degenerative changes.
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Affiliation(s)
- Yuchun Zou
- Fujian Key Laboratory of Oral Diseases & Fujian Provincial Engineering Research Center of Oral Biomaterial & Stomatological Key Lab of Fujian College and University, School and Hospital of Stomatology, Fujian Medical University, China.,Orthodontics Department, School and Hospital of Stomatology, Fujian Medical University, Fuzhou, 350001, China
| | - Hanyu Lin
- Fujian Key Laboratory of Oral Diseases & Fujian Provincial Engineering Research Center of Oral Biomaterial & Stomatological Key Lab of Fujian College and University, School and Hospital of Stomatology, Fujian Medical University, China.,Orthodontics Department, School and Hospital of Stomatology, Fujian Medical University, Fuzhou, 350001, China
| | - Jingwen Cai
- Fujian Key Laboratory of Oral Diseases & Fujian Provincial Engineering Research Center of Oral Biomaterial & Stomatological Key Lab of Fujian College and University, School and Hospital of Stomatology, Fujian Medical University, China.,Orthodontics Department, School and Hospital of Stomatology, Fujian Medical University, Fuzhou, 350001, China.,Institute of Stomatology & Research Center of Dental and Craniofacial Implants, School and Hospital of Stomatology, Fujian Medical University, China
| | - Qingqi Xie
- Fujian Key Laboratory of Oral Diseases & Fujian Provincial Engineering Research Center of Oral Biomaterial & Stomatological Key Lab of Fujian College and University, School and Hospital of Stomatology, Fujian Medical University, China.,Orthodontics Department, School and Hospital of Stomatology, Fujian Medical University, Fuzhou, 350001, China
| | - Weijia Chen
- Fujian Key Laboratory of Oral Diseases & Fujian Provincial Engineering Research Center of Oral Biomaterial & Stomatological Key Lab of Fujian College and University, School and Hospital of Stomatology, Fujian Medical University, China.,Orthodontics Department, School and Hospital of Stomatology, Fujian Medical University, Fuzhou, 350001, China
| | - You-Guang Lu
- Fujian Key Laboratory of Oral Diseases & Fujian Provincial Engineering Research Center of Oral Biomaterial & Stomatological Key Lab of Fujian College and University, School and Hospital of Stomatology, Fujian Medical University, China.,Department of Preventive Dentistry, School and Hospital of Stomatology, Fujian Medical University, Fuzhou, 350001, China
| | - Linyu Xu
- Fujian Key Laboratory of Oral Diseases & Fujian Provincial Engineering Research Center of Oral Biomaterial & Stomatological Key Lab of Fujian College and University, School and Hospital of Stomatology, Fujian Medical University, China.,Orthodontics Department, School and Hospital of Stomatology, Fujian Medical University, Fuzhou, 350001, China
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5
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Zhang Z, Yaryhin O, Koyabu D, Werneburg I. Morphological association between muscle attachments and ossification sites in the late cartilaginous skull of tuatara embryos. J Morphol 2022; 283:908-931. [DOI: 10.1002/jmor.21474] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Revised: 03/11/2022] [Accepted: 03/20/2022] [Indexed: 11/11/2022]
Affiliation(s)
- Zitong Zhang
- Fachbereich Geowissenschaften, Universität Tübingen Hölderlinstraße 12 72074 Tübingen Germany
- Fachbereich Biologie, Universität Tübingen Auf der Morgenstelle 28 72076 Tübingen Germany
| | | | - Daisuke Koyabu
- Research and Development Center for Precision Medicine University of Tsukuba 1‐2 Kasuga, Tsukuba‐shi Ibaraki 305‐8550 Japan
- Department of Molecular Craniofacial Embryology Tokyo Medical and Dental University 1‐5‐45 Yushima, Bunkyo‐ku Tokyo 113‐8549 Japan
| | - Ingmar Werneburg
- Fachbereich Geowissenschaften, Universität Tübingen Hölderlinstraße 12 72074 Tübingen Germany
- Senckenberg Centre for Human Evolution and Palaeoenvironment (SHEP) an der Universität Tübingen Hölderlinstraße 12 Tübingen 72076 Germany
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6
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Hassan MG, Chen C, Ismail HA, Zaher AR, Cox TC, Goodwin AF, Jheon AH. Altering calcium and phosphorus supplementation in pregnancy and lactation affects offspring craniofacial morphology in a sex-specific pattern. Am J Orthod Dentofacial Orthop 2022; 161:e446-e455. [DOI: 10.1016/j.ajodo.2021.12.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 12/01/2021] [Accepted: 12/01/2021] [Indexed: 11/01/2022]
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7
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Katsube M, Yamada S, Utsunomiya N, Yamaguchi Y, Takakuwa T, Yamamoto A, Imai H, Saito A, Vora SR, Morimoto N. A 3D analysis of growth trajectory and integration during early human prenatal facial growth. Sci Rep 2021; 11:6867. [PMID: 33767268 PMCID: PMC7994314 DOI: 10.1038/s41598-021-85543-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Accepted: 02/26/2021] [Indexed: 01/03/2023] Open
Abstract
Significant shape changes in the human facial skeleton occur in the early prenatal period, and understanding this process is critical for studying a myriad of congenital facial anomalies. However, quantifying and visualizing human fetal facial growth has been challenging. Here, we applied quantitative geometric morphometrics (GM) to high-resolution magnetic resonance images of human embryo and fetuses, to comprehensively analyze facial growth. We utilized non-linear growth estimation and GM methods to assess integrated epigenetic growth between masticatory muscles and associated bones. Our results show that the growth trajectory of the human face in the early prenatal period follows a curved line with three flexion points. Significant antero-posterior development occurs early, resulting in a shift from a mandibular prognathic to relatively orthognathic appearance, followed by expansion in the lateral direction. Furthermore, during this time, the development of the zygoma and the mandibular ramus is closely integrated with the masseter muscle.
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Affiliation(s)
- Motoki Katsube
- Department of Plastic and Reconstructive Surgery, Kyoto University Graduate School of Medicine, 54 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto, 606-8507, Japan.
| | - Shigehito Yamada
- Congenital Anomaly Research Center, Kyoto University Graduate School of Medicine, Yoshida-Konoe-cho, Sakyo-ku, Kyoto, 606-8501, Japan.,Human Health Sciences, Kyoto University Graduate School of Medicine, 53 Shogoin-Kawahara-cho, Sakyo-ku, Kyoto, 606-8507, Japan
| | - Natsuko Utsunomiya
- Department of Plastic and Reconstructive Surgery, Kyoto University Graduate School of Medicine, 54 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto, 606-8507, Japan.,Congenital Anomaly Research Center, Kyoto University Graduate School of Medicine, Yoshida-Konoe-cho, Sakyo-ku, Kyoto, 606-8501, Japan
| | - Yutaka Yamaguchi
- Human Health Sciences, Kyoto University Graduate School of Medicine, 53 Shogoin-Kawahara-cho, Sakyo-ku, Kyoto, 606-8507, Japan
| | - Tetsuya Takakuwa
- Human Health Sciences, Kyoto University Graduate School of Medicine, 53 Shogoin-Kawahara-cho, Sakyo-ku, Kyoto, 606-8507, Japan
| | - Akira Yamamoto
- Department of Diagnostic Imaging and Nuclear Medicine, Kyoto University Graduate School of Medicine, 54 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto, 606-8507, Japan
| | - Hirohiko Imai
- Department of Systems Science, Kyoto University Graduate School of Informatics, Yoshida-Honmachi, Sakyo-ku, Kyoto, 606-8501, Japan
| | - Atsushi Saito
- Institute of Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei-shi, Tokyo, 184-8588, Japan
| | - Siddharth R Vora
- Oral Health Sciences, University of British Columbia, JBM 372-2199 Wesbrook Mall, Vancouver, BC, V6T 1Z3, Canada
| | - Naoki Morimoto
- Department of Plastic and Reconstructive Surgery, Kyoto University Graduate School of Medicine, 54 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto, 606-8507, Japan
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8
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Botzenhart UU, Keil C, Tsagkari E, Zeidler-Rentzsch I, Gredes T, Gedrange T. Influence of botulinum toxin A on craniofacial morphology after injection into the right masseter muscle of dystrophin deficient (mdx-) mice. Ann Anat 2021; 236:151715. [PMID: 33675949 DOI: 10.1016/j.aanat.2021.151715] [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: 01/08/2021] [Revised: 01/22/2021] [Accepted: 01/29/2021] [Indexed: 10/22/2022]
Abstract
BACKGROUND Severe craniofacial and dental abnormalities, typical for patients with progressive Duchenne muscular dystrophy (DMD), are an exellcent demonstration of Melvin L. Moss "functional matrix theory", highlighting the influence of muscle tissue on craniofacial growth and morphology. However, the currently best approved animal model for investigation of this interplay is the mdx-mouse, which offers only a limited time window for research, due to the ability of muscle regeneration, in contrast to the human course of the disease. The aim of this study was to evaluate craniofacial morphology after BTX-A induced muscle paralysis in C57Bl- and mdx-mice, to prove the suitability of BTX-A intervention to inhibit muscle regeneration in mdx-mice and thus, mimicking the human course of the DMD disease. METHODS Paralysis of the right masseter muscle was induced in 100 days old C57Bl- and mdx-mice by a single specific intramuscular BTX-A injection. Mice skulls were obtained at 21 days and 42 days after BTX-A injection and 3D radiological evaluation was performed in order to measure various craniofacial dimensions in the sagittal, transversal and vertical plane. Statstical analysis were performed using SigmaStat®Version 3.5. In case of normal distribution, unpaired t-test and otherwise the Mann-Whitney-U test was applied. A statistical significance was given in case of p ≤ 0.05. RESULTS In contrast to C57Bl-mice, in mdx-mice, three weeks after BTX-A treatment a significant decrease of skull dimensions was noted in most of the measurements followed by a significant increase at the second investigation period. CONCLUSIONS BTX-A can induce changes in craniofacial morphology and presumably partially inhibit muscle regeneration in mdx-mice, but cannot completely intensify craniofacial effects elicited by dystrophy. Further research is necessary in order to fully understand muscle-bone interplay after BTX-A injection into dystrophic muscles.
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Affiliation(s)
| | - Christiane Keil
- Medical Faculty Carl Gustav Carus Campus, TU Dresden, 01307, Dresden, Germany; Department of Orthodontics, Carl Gustav Carus Campus, TU Dresden, 01307, Dresden, Germany
| | - Eirini Tsagkari
- Department of Orthodontics, Faculty of Dentistry School of Health Sciences, Aristotle University of Thessaloniki, 54124, Thessaloniki, Greece
| | - Ines Zeidler-Rentzsch
- Department of Otorhinolaryngology, Head and Neck Surgery, Carl Gustav Carus Campus, TU Dresden, 01307, Dresden, Germany
| | - Tomasz Gredes
- Medical Faculty Carl Gustav Carus Campus, TU Dresden, 01307, Dresden, Germany; Department of Orthodontics, Carl Gustav Carus Campus, TU Dresden, 01307, Dresden, Germany
| | - Tomasz Gedrange
- Medical Faculty Carl Gustav Carus Campus, TU Dresden, 01307, Dresden, Germany
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Brassard C, Merlin M, Guintard C, Monchâtre-Leroy E, Barrat J, Callou C, Cornette R, Herrel A. Interrelations Between the Cranium, the Mandible and Muscle Architecture in Modern Domestic Dogs. Evol Biol 2020. [DOI: 10.1007/s11692-020-09515-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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10
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Yamamoto M, Takada H, Ishizuka S, Kitamura K, Jeong J, Sato M, Hinata N, Abe S. Morphological association between the muscles and bones in the craniofacial region. PLoS One 2020; 15:e0227301. [PMID: 31923241 PMCID: PMC6953862 DOI: 10.1371/journal.pone.0227301] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2019] [Accepted: 12/16/2019] [Indexed: 01/02/2023] Open
Abstract
The strains of inbred laboratory mice are isogenic and homogeneous for over 98.6% of their genomes. However, geometric morphometric studies have demonstrated clear differences among the skull shapes of various mice strains. The question now arises: why are skull shapes different among the mice strains? Epigenetic processes, such as morphological interaction between the muscles and bones, may cause differences in the skull shapes among various mice strains. To test these predictions, the objective of this study is to examine the morphological association between a specific part of the skull and its adjacent muscle. We examined C57BL6J, BALB/cA, and ICR mice on embryonic days (E) 12.5 and 16.5 as well as on postnatal days (P) 0, 10, and 90. As a result, we found morphological differences between C57BL6J and BALB/cA mice with respect to the inferior spine of the hypophyseal cartilage or basisphenoid (SP) and the tensor veli palatini muscle (TVP) during the prenatal and postnatal periods. There was a morphological correlation between the SP and the TVP in the C57BL6J, BALB/cA, and ICR mice during E15 and P0. However, there were not correlation between the TVP and the SP during P10. After discectomy, bone deformation was associated with a change in the shape of the adjacent muscle. Therefore, epigenetic modifications linked to the interaction between the muscles and bones might occur easily during the prenatal period, and inflammation seems to allow epigenetic modifications between the two to occur.
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Affiliation(s)
- Masahito Yamamoto
- Department of Anatomy, Tokyo Dental College, Tokyo, Japan
- Tokyo Dental College Research Branding Project, Tokyo Dental College, Tokyo, Japan
| | | | - Satoshi Ishizuka
- Department of Anatomy, Tokyo Dental College, Tokyo, Japan
- Tokyo Dental College Research Branding Project, Tokyo Dental College, Tokyo, Japan
| | - Kei Kitamura
- Tokyo Dental College Research Branding Project, Tokyo Dental College, Tokyo, Japan
- Department of Histology and Developmental Biology, Tokyo Dental College, Tokyo, Japan
| | - Juhee Jeong
- Department of Basic Science and Craniofacial Biology, New York University College of Dentistry, New York, NY, United States of America
| | - Masaki Sato
- Tokyo Dental College Research Branding Project, Tokyo Dental College, Tokyo, Japan
- Laboratory of Biology, Tokyo Dental College, Tokyo, Japan
| | - Nobuyuki Hinata
- Department of Urology, Kobe University Graduate School of Medicine, Hyogo, Japan
| | - Shinichi Abe
- Department of Anatomy, Tokyo Dental College, Tokyo, Japan
- Tokyo Dental College Research Branding Project, Tokyo Dental College, Tokyo, Japan
- * E-mail:
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11
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Buvinic S, Balanta-Melo J, Kupczik K, Vásquez W, Beato C, Toro-Ibacache V. Muscle-Bone Crosstalk in the Masticatory System: From Biomechanical to Molecular Interactions. Front Endocrinol (Lausanne) 2020; 11:606947. [PMID: 33732211 PMCID: PMC7959242 DOI: 10.3389/fendo.2020.606947] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Accepted: 12/31/2020] [Indexed: 12/12/2022] Open
Abstract
The masticatory system is a complex and highly organized group of structures, including craniofacial bones (maxillae and mandible), muscles, teeth, joints, and neurovascular elements. While the musculoskeletal structures of the head and neck are known to have a different embryonic origin, morphology, biomechanical demands, and biochemical characteristics than the trunk and limbs, their particular molecular basis and cell biology have been much less explored. In the last decade, the concept of muscle-bone crosstalk has emerged, comprising both the loads generated during muscle contraction and a biochemical component through soluble molecules. Bone cells embedded in the mineralized tissue respond to the biomechanical input by releasing molecular factors that impact the homeostasis of the attaching skeletal muscle. In the same way, muscle-derived factors act as soluble signals that modulate the remodeling process of the underlying bones. This concept of muscle-bone crosstalk at a molecular level is particularly interesting in the mandible, due to its tight anatomical relationship with one of the biggest and strongest masticatory muscles, the masseter. However, despite the close physical and physiological interaction of both tissues for proper functioning, this topic has been poorly addressed. Here we present one of the most detailed reviews of the literature to date regarding the biomechanical and biochemical interaction between muscles and bones of the masticatory system, both during development and in physiological or pathological remodeling processes. Evidence related to how masticatory function shapes the craniofacial bones is discussed, and a proposal presented that the masticatory muscles and craniofacial bones serve as secretory tissues. We furthermore discuss our current findings of myokines-release from masseter muscle in physiological conditions, during functional adaptation or pathology, and their putative role as bone-modulators in the craniofacial system. Finally, we address the physiological implications of the crosstalk between muscles and bones in the masticatory system, analyzing pathologies or clinical procedures in which the alteration of one of them affects the homeostasis of the other. Unveiling the mechanisms of muscle-bone crosstalk in the masticatory system opens broad possibilities for understanding and treating temporomandibular disorders, which severely impair the quality of life, with a high cost for diagnosis and management.
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Affiliation(s)
- Sonja Buvinic
- Institute for Research in Dental Sciences, Faculty of Dentistry, Universidad de Chile, Santiago, Chile
- Center for Exercise, Metabolism and Cancer Studies CEMC2016, Faculty of Medicine, Universidad de Chile, Santiago, Chile
- *Correspondence: Sonja Buvinic,
| | - Julián Balanta-Melo
- School of Dentistry, Faculty of Health, Universidad del Valle, Cali, Colombia
- Evidence-Based Practice Unit Univalle, Hospital Universitario del Valle, Cali, Colombia
- Max Planck Weizmann Center for Integrative Archaeology and Anthropology, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | - Kornelius Kupczik
- Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | - Walter Vásquez
- Institute for Research in Dental Sciences, Faculty of Dentistry, Universidad de Chile, Santiago, Chile
| | - Carolina Beato
- Institute for Research in Dental Sciences, Faculty of Dentistry, Universidad de Chile, Santiago, Chile
| | - Viviana Toro-Ibacache
- Institute for Research in Dental Sciences, Faculty of Dentistry, Universidad de Chile, Santiago, Chile
- Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
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12
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Eyquem AP, Kuzminsky SC, Aguilera J, Astudillo W, Toro-Ibacache V. Normal and altered masticatory load impact on the range of craniofacial shape variation: An analysis of pre-Hispanic and modern populations of the American Southern Cone. PLoS One 2019; 14:e0225369. [PMID: 31826020 PMCID: PMC6905515 DOI: 10.1371/journal.pone.0225369] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2019] [Accepted: 11/04/2019] [Indexed: 01/31/2023] Open
Abstract
The reduction of masticatory load intensity resulting from dietary changes in human evolution has been proposed as an important factor that alters craniofacial shape in past and current populations. However, its impact on craniofacial variation and on the perceived differences among populations is unclear. The maxillomandibular relationship, which alters masticatory force direction, is a factor often neglected but it can contribute to variation in craniofacial morphology, particularly among modern/urban populations where the prevalence of dental malocclusions is greater than in prehistoric populations. This study investigates the influence of masticatory load intensity and maxillomandibular relationship as a proxy for force direction on the human craniofacial skeleton. By using 3D imaging and geometric morphometrics, we analyzed craniofacial shape variation among 186 individuals from pre-Hispanic and modern Chilean and Argentinean populations that differ in diet consistency (a proxy for masticatory load intensity) and maxillomandibular relationship. We predicted that masticatory load would have a subtle effect on the upper craniofacial bones and that this would be more marked in the maxilla. Our results showed no clear influence of masticatory load on craniofacial shape, particularly in modern/urban populations. Allometry, on the contrary, shows a stronger effect. The degree of integration between the upper craniofacial bones and the load-bearing maxilla depends on masticatory load intensity, decreasing from high to low but showing a conservative pattern of covariation among the groups. The degree of variation in the shape of the maxilla is greater than the upper craniofacial bones. These results suggest that masticatory load has a limited effect in determining differences in craniofacial morphology among populations. This effect is slightly greater for the maxillary region of the face. We propose that the reduction of functional constraints is key to greater shape variation found in modern/urban populations.
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Affiliation(s)
- Andrea P. Eyquem
- Centro de Análisis Cuantitativo en Antropología Dental, Facultad de Odontología, Universidad de Chile, Santiago, Chile
- Max Planck Weizmann Center for Integrative Archaeology and Anthropology, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | - Susan C. Kuzminsky
- Department of Anthropology and Applied Archaeology, Eastern New Mexico University, Portales, New Mexico, United States of America
- Anthropology Department, University of California, Santa Cruz, California, United States of America
| | - José Aguilera
- Facultad de Medicina and Hospital Clínico, Universidad de Chile, Santiago, Chile
| | - Williams Astudillo
- Facultad de Medicina and Hospital Clínico, Universidad de Chile, Santiago, Chile
| | - Viviana Toro-Ibacache
- Centro de Análisis Cuantitativo en Antropología Dental, Facultad de Odontología, Universidad de Chile, Santiago, Chile
- Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
- * E-mail: ,
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13
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Espinosa S, Rabanal C, Toro-Ibacache V. Morphometric Characterization of Asymmetric Mandibles Due to Condylar Hyperactivity. J Oral Maxillofac Surg 2019; 77:1056-1067. [PMID: 30689968 DOI: 10.1016/j.joms.2018.12.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Revised: 12/17/2018] [Accepted: 12/17/2018] [Indexed: 11/29/2022]
Abstract
PURPOSE Mandibular asymmetry related to condylar hyperactivity (CH) presents a complex set of morphologic features that pose challenges for its correction. Using state-of-the-art morphometric techniques, this report provides a detailed and hierarchical description of the features present in CH-related asymmetric mandibles and offers new knowledge for the surgical treatment of CH. MATERIALS AND METHODS Sixty patients were included in the sample. Thirty had CH-related asymmetric mandibles and the other 30 had clinically symmetric mandibles. Twenty-eight 3-dimensional landmarks were placed on computed tomographically based reconstructions of each participant's mandible and analyzed using geometric morphometric analysis for the quantitative and qualitative comparison of their morphologic features. RESULTS All 60 participants exhibited asymmetry. However, those with CH exhibited a broad range of shapes and even shared several morphologic features with the controls. Mainly the ramus and then the body were the main contributors of the differences between groups. CONCLUSIONS There is considerable overlap of anatomic features characterizing symmetric and asymmetric mandibles; based on shape alone, the 2 groups can be easily misclassified. The ramus and body of the affected side in CH-related asymmetric mandibles were the main contributors to asymmetry of the structure. The chin, a usual diagnostic structure, did not greatly contribute to the structural asymmetry of the mandible.
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Affiliation(s)
- Sebastian Espinosa
- Attending Surgeon, Department of Oral and Maxillofacial Surgery, Hospital Sótero del Río, Santiago, Chile.
| | - Carolina Rabanal
- Attending Radiologist, Department of Oral and Maxillofacial Radiology, Hospital Sótero del Río, Santiago, Chile
| | - Viviana Toro-Ibacache
- Researcher, Centro de Análisis Cuantitativo en Antropología Dental, Facultad de Odontología, Universidad de Chile, Santiago, Chile; Researcher, Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
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14
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Toro-Ibacache V, Ugarte F, Morales C, Eyquem A, Aguilera J, Astudillo W. Dental malocclusions are not just about small and weak bones: assessing the morphology of the mandible with cross-section analysis and geometric morphometrics. Clin Oral Investig 2019; 23:3479-3490. [PMID: 30604093 DOI: 10.1007/s00784-018-2766-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Accepted: 12/04/2018] [Indexed: 12/26/2022]
Abstract
OBJECTIVES Dental malocclusions in modern populations would be the result of small and weak jaws developing under low masticatory loads. We assess the validity of this by characterising the external and internal morphology of mandibles affected by class II and III malocclusions and comparing them with those from individuals with different masticatory load patterns. MATERIALS AND METHODS CTs from up to 118 individuals exerting intensive, medium and low masticatory loads with harmonic occlusion, and from class II and III individuals, were used to compare their external shape using geometric morphometrics, as well as their internal amount and distribution of cortical bone. RESULTS The low-load groups (harmonic, class II and III occlusion) are externally more gracile than the intense and medium load groups. But more relevant in shape variation is a marked allometric pattern, which differentiates class II (small) and III (large) mandibles. Despite gracility, the relative amount of cortical bone in the low-load groups is larger than in the remaining groups. CONCLUSIONS There is no evidence that the modern mandible, including class II and III individuals, is intrinsically small and weak. Instead, there is a rather large degree of morphological variation, which could be linked to a lack of constraints derived from low masticatory loads. Thus, the effect of other factors such as genetics, but also basal metabolism, should be looked in more depth. CLINICAL RELEVANCE Dental malocclusions are a common disorder whose aetiology has not been unravelled, and several to be considered in the prevention and therapy of malocclusion.
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Affiliation(s)
- Viviana Toro-Ibacache
- Centro de Análisis Cuantitativo en Antropología Dental and Instituto de Investigación en Ciencias Odontológicas, Facultad de Odontología, Universidad de Chile, Olivos 943, Independencia, Santiago, Chile. .,Department of Human Evolution, Mac Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, 04103, Leipzig, Germany.
| | - Francisco Ugarte
- Centro de Análisis Cuantitativo en Antropología Dental, Facultad de Odontología, Universidad de Chile, Santiago, Chile
| | - Cristina Morales
- Centro de Análisis Cuantitativo en Antropología Dental, Facultad de Odontología, Universidad de Chile, Santiago, Chile
| | - Andrea Eyquem
- Departamento de Antropología, Facultad de Ciencias Sociales, Universidad de Chile, Santiago, Chile.,Max Planck Weizmann Center for Integrative Archaeology and Anthropology, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | - José Aguilera
- Facultad de Medicina and Hospital Clínico, Universidad de Chile, Santiago, Chile
| | - Williams Astudillo
- Facultad de Medicina and Hospital Clínico, Universidad de Chile, Santiago, Chile
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15
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Conith AJ, Lam DT, Albertson RC. Muscle-induced loading as an important source of variation in craniofacial skeletal shape. Genesis 2018; 57:e23263. [PMID: 30418689 DOI: 10.1002/dvg.23263] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 10/25/2018] [Accepted: 10/27/2018] [Indexed: 01/01/2023]
Abstract
The shape of the craniofacial skeleton is constantly changing through ontogeny and reflects a balance between developmental patterning and mechanical-load-induced remodeling. Muscles are a major contributor to producing the mechanical environment that is crucial for "normal" skull development. Here, we use an F5 hybrid population of Lake Malawi cichlids to characterize the strength and types of associations between craniofacial bones and muscles. We focus on four bones/bone complexes, with different developmental origins, alongside four muscles with distinct functions. We used micro-computed tomography to extract 3D information on bones and muscles. 3D geometric morphometrics and volumetric measurements were used to characterize bone and muscle shape, respectively. Linear regressions were performed to test for associations between bone shape and muscle volume. We identified three types of associations between muscles and bones: weak, strong direct (i.e., muscles insert directly onto bone), and strong indirect (i.e., bone is influenced by muscles without a direct connection). In addition, we show that although the shape of some bones is relatively robust to muscle-induced mechanical stimulus, others appear to be highly sensitive to muscular input. Our results imply that the roles for muscular input on skeletal shape extend beyond specific points of origin or insertion and hold significant potential to influence broader patterns of craniofacial geometry. Thus, changes in the loading environment, either as a normal course of ontogeny or if an organism is exposed to a novel environment, may have pronounced effects on skeletal shape via near and far-ranging effects of muscular loading.
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Affiliation(s)
- Andrew J Conith
- Biology Department, University of Massachusetts Amherst, Amherst, Massachusetts
| | - Daniel T Lam
- Biology Department, University of Massachusetts Amherst, Amherst, Massachusetts
| | - R Craig Albertson
- Biology Department, University of Massachusetts Amherst, Amherst, Massachusetts
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16
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Balanta-Melo J, Torres-Quintana MA, Bemmann M, Vega C, González C, Kupczik K, Toro-Ibacache V, Buvinic S. Masseter muscle atrophy impairs bone quality of the mandibular condyle but not the alveolar process early after induction. J Oral Rehabil 2018; 46:233-241. [PMID: 30468522 DOI: 10.1111/joor.12747] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Revised: 11/15/2018] [Accepted: 11/17/2018] [Indexed: 12/27/2022]
Abstract
BACKGROUND Masseter muscle function influences mandibular bone homeostasis. As previously reported, bone resorption markers increased in the mouse mandibular condyle two days after masseter paralysis induced with botulinum toxin type A (BoNTA), followed by local bone loss. OBJECTIVE This study aimed to evaluate the bone quality of both the mandibular condyle and alveolar process in the mandible of adult mice during the early stage of a BoNTA-induced masseter muscle atrophy, using a combined 3D histomorphometrics and shape analysis approach. METHODS Adult BALB/c mice were divided into an untreated control group and an experimental group; the latter received one single BoNTA injection in the right masseter (BoNTA-right) and saline in the left masseter (Saline-left). 3D bone microstructural changes in the mandibular condyle and alveolar process were determined with high-resolution microtomography. Additionally, landmark-based geometric morphometrics was implemented to assess external shape changes. RESULTS After 2 weeks, masseter mass was significantly reduced (P-value <0.001). When compared to Saline-left and untreated condyles, BoNTA-right condyles showed significant bone loss (P-value <0.001) and shape changes. No significant bone loss was observed in the alveolar processes of any of the groups (P-value >0.05). CONCLUSION Condyle bone quality deteriorates at an early stage of BoNTA-induced masseter muscle atrophy, and before the alveolar process is affected. Since the observed bone microstructural changes resemble those in human temporomandibular joint degenerative disorders, the clinical safety of BoNTA intervention in the masticatory apparatus remains to be clarified.
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Affiliation(s)
- Julián Balanta-Melo
- Institute for Research in Dental Sciences, Faculty of Dentistry, Universidad de Chile, Santiago, Chile.,School of Dentistry, Universidad del Valle, Cali, Colombia.,Max Planck Weizmann Center for Integrative Archaeology and Anthropology, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | | | - Maximilian Bemmann
- Max Planck Weizmann Center for Integrative Archaeology and Anthropology, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | - Carolina Vega
- Institute for Research in Dental Sciences, Faculty of Dentistry, Universidad de Chile, Santiago, Chile
| | | | - Kornelius Kupczik
- Max Planck Weizmann Center for Integrative Archaeology and Anthropology, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany.,Center for Quantitative Analysis in Dental Anthropology, Faculty of Dentistry, Universidad de Chile, Santiago, Chile
| | - Viviana Toro-Ibacache
- Institute for Research in Dental Sciences, Faculty of Dentistry, Universidad de Chile, Santiago, Chile.,Center for Quantitative Analysis in Dental Anthropology, Faculty of Dentistry, Universidad de Chile, Santiago, Chile.,Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | - Sonja Buvinic
- Institute for Research in Dental Sciences, Faculty of Dentistry, Universidad de Chile, Santiago, Chile.,Center for Exercise, Metabolism and Cancer Studies CEMC2016, Faculty of Medicine, Universidad de Chile, Santiago, Chile
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17
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Balanta-Melo J, Toro-Ibacache V, Torres-Quintana MA, Kupczik K, Vega C, Morales C, Hernández-Moya N, Arias-Calderón M, Beato C, Buvinic S. Early molecular response and microanatomical changes in the masseter muscle and mandibular head after botulinum toxin intervention in adult mice. Ann Anat 2017; 216:112-119. [PMID: 29289710 DOI: 10.1016/j.aanat.2017.11.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Revised: 11/22/2017] [Accepted: 11/27/2017] [Indexed: 11/19/2022]
Abstract
BACKGROUND Masseter muscle paralysis induced by botulinum toxin type A (BoNTA) evokes subchondral bone loss in mandibular heads of adult rats and growing mice after 4 weeks. However, the primary cellular and molecular events leading to altered bone remodeling remain unexplored. Thus, the aim of the current work has been to assess the molecular response that precedes the early microanatomical changes in the masseter muscle and subchondral bone of the mandibular head in adult mice after BoNTA intervention. METHODS A pre-clinical in vivo study was performed by a single intramuscular injection of 0.2 U BoNTA in the right masseter (experimental) of adult BALB/c mice. The contralateral masseter was injected with vehicle (control). Changes in mRNA levels of molecular markers of bone loss or muscle atrophy/regeneration were addressed by qPCR at day 2 or 7, respectively. mRNA levels of receptor activator of nuclear factor-κB ligand (RANKL) was assessed in mandibular heads, whilst mRNA levels of Atrogin-1/MAFbx, MuRF-1 and Myogenin were addressed in masseter muscles. In order to identify the early microanatomical changes at day 14, fiber diameters in transversal sections of masseter muscles were quantified, and histomorphometric analysis was used to determine the bone per tissue area and the trabecular thickness of subchondral bone of the mandibular heads. RESULTS An increase of up to 4-fold in RANKL mRNA levels were detected in mandibular heads of the BoNTA-injected sides as early as 2 days after intervention. Moreover, a 4-6 fold increase in Atrogin-1/MAFbx and MuRF-1 and an up to 25 fold increase in Myogenin mRNA level were detected in masseter muscles 7 days after BoNTA injections. Masseter muscle mass, as well as individual muscle fiber diameter, were significantly reduced in BoNTA-injected side after 14 days post-intervention. At the same time, in the mandibular heads from the treated side, the subchondral bone loss was evinced by a significant reduction in bone per tissue area (-40%) and trabecular thickness (-55%). CONCLUSIONS Our results show that masseter muscle paralysis induced by BoNTA leads to significant microanatomical changes by day 14, preceded by molecular changes as early as 2 days in bone, and 7 days in muscle. Therefore, masseter muscle atrophy and subchondral bone loss detected at 14 days are preceded by molecular responses that occur during the first week after BoNTA intervention.
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Affiliation(s)
- Julián Balanta-Melo
- Institute for Research in Dental Sciences, Faculty of Dentistry, Universidad de Chile, Chile; School of Dentistry, Universidad del Valle, Colombia
| | - Viviana Toro-Ibacache
- Institute for Research in Dental Sciences, Faculty of Dentistry, Universidad de Chile, Chile; Quantitative Analysis Center in Dental Anthropology, Faculty of Dentistry, Universidad de Chile, Chile; Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Germany
| | | | - Kornelius Kupczik
- Max Planck Weizmann Center for Integrative Archaeology and Anthropology, Max Planck Institute for Evolutionary Anthropology, Germany
| | - Carolina Vega
- Institute for Research in Dental Sciences, Faculty of Dentistry, Universidad de Chile, Chile
| | - Camilo Morales
- Institute for Research in Dental Sciences, Faculty of Dentistry, Universidad de Chile, Chile; Department of Basic Sciences, Health Faculty, Pontificia Universidad Javeriana, Colombia; Institute of Biomedical Sciences, Faculty of Medicine, Universidad de Chile, Chile
| | - Nadia Hernández-Moya
- Institute for Research in Dental Sciences, Faculty of Dentistry, Universidad de Chile, Chile
| | - Manuel Arias-Calderón
- Institute for Research in Dental Sciences, Faculty of Dentistry, Universidad de Chile, Chile; Institute of Biomedical Sciences, Faculty of Medicine, Universidad de Chile, Chile
| | - Carolina Beato
- Institute for Research in Dental Sciences, Faculty of Dentistry, Universidad de Chile, Chile; Institute of Biomedical Sciences, Faculty of Medicine, Universidad de Chile, Chile
| | - Sonja Buvinic
- Institute for Research in Dental Sciences, Faculty of Dentistry, Universidad de Chile, Chile.
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