Mandibular Vertical Growth Deficiency After Botulinum-Induced Hypotrophy of Masticatory Closing Muscles in Juvenile Nonhuman Primates
The purpose of this study was to investigate the relationship between masticatory muscular hypotrophy and mandibular growth in juvenile nonhuman primates (cynolmolgus monkeys, Macaca fasicularis). We hypothesized that botulinum toxin (BTX)-induced neuro-muscular junctional block and its resultant hy...
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| Language: | English |
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Frontiers Media S.A.
2019-04-01
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| Series: | Frontiers in Physiology |
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| Online Access: | https://www.frontiersin.org/article/10.3389/fphys.2019.00496/full |
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| author | Hak-Jin Kim Hye-Jin Tak Joo-Won Moon Sang-Hoon Kang Seong Taek Kim Jinquan He Zhenguo Piao Sang-Hwy Lee |
| author_facet | Hak-Jin Kim Hye-Jin Tak Joo-Won Moon Sang-Hoon Kang Seong Taek Kim Jinquan He Zhenguo Piao Sang-Hwy Lee |
| author_sort | Hak-Jin Kim |
| collection | DOAJ |
| description | The purpose of this study was to investigate the relationship between masticatory muscular hypotrophy and mandibular growth in juvenile nonhuman primates (cynolmolgus monkeys, Macaca fasicularis). We hypothesized that botulinum toxin (BTX)-induced neuro-muscular junctional block and its resultant hypotrophy of masticatory muscles would produce mandibular growth disturbances in size and shape. Ten male cynomolgus monkeys were divided into three groups: group I (control; n = 3), group II (unilateral BTX; n = 4), and group III (bilateral BTX; n = 3). The unilateral or bilateral muscular hypotrophy of major masticatory closing muscles was induced by synchronous BTX application to masseter, medial pterygoid, and temporal muscle. Mandibular growth was tracked by linear, angular, area and volume measurements using three-dimensional (3D) computed tomography imaging before BTX treatment and after 3 and 6 months. After unilateral hypotrophy of masticatory muscles in group II, vertical growth deficiency was prominent on the BTX side, with compensatory overgrowth on the control side. The bilateral muscular hypotrophy in group III also showed smaller ramal height and width than that of control (group I) and control side (group II). Moreover, ramal sagittal angles (posterior tilt) increased on the BTX side of both groups II and III, but coronal angles (lateral tilt) did so on the BTX side of group II, resulting in asymmetry. The results confirmed our hypothesis that functional activity of masticatory closing muscles is closely related to mandibular growth in size and shape of juvenile nonhuman primates. In addition, the focused growth disturbances on the ramal height and posterior-lateral tilt suggested the possible role of masticatory closing muscles for ramal vertical and angular growth vector of the mandible. |
| first_indexed | 2024-04-13T22:35:50Z |
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| id | doaj.art-f3897205fc194d9c8c3cc0f3f9a819e6 |
| institution | Directory Open Access Journal |
| issn | 1664-042X |
| language | English |
| last_indexed | 2024-04-13T22:35:50Z |
| publishDate | 2019-04-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Physiology |
| spelling | doaj.art-f3897205fc194d9c8c3cc0f3f9a819e62022-12-22T02:26:47ZengFrontiers Media S.A.Frontiers in Physiology1664-042X2019-04-011010.3389/fphys.2019.00496447088Mandibular Vertical Growth Deficiency After Botulinum-Induced Hypotrophy of Masticatory Closing Muscles in Juvenile Nonhuman PrimatesHak-Jin Kim0Hye-Jin Tak1Joo-Won Moon2Sang-Hoon Kang3Seong Taek Kim4Jinquan He5Zhenguo Piao6Sang-Hwy Lee7Department of Oral and Maxillofacial Surgery, College of Dentistry, Yonsei University, Seoul, South KoreaOral Science Research Center, College of Dentistry, Yonsei University, Seoul, South KoreaOral Science Research Center, College of Dentistry, Yonsei University, Seoul, South KoreaDepartment of Oral and Maxillofacial Surgery, National Health Insurance Service, Ilsan Hospital, Goyang, South KoreaDepartment of Oral Medicine, College of Dentistry, Yonsei University, Seoul, South KoreaDepartment of Oral and Maxillofacial Surgery, Stomatology Hospital of Guangzhou Medical University, Guangzhou, ChinaDepartment of Oral and Maxillofacial Surgery, Stomatology Hospital of Guangzhou Medical University, Guangzhou, ChinaDepartment of Oral and Maxillofacial Surgery, Oral Science Research Center, College of Dentistry, Yonsei University, Seoul, South KoreaThe purpose of this study was to investigate the relationship between masticatory muscular hypotrophy and mandibular growth in juvenile nonhuman primates (cynolmolgus monkeys, Macaca fasicularis). We hypothesized that botulinum toxin (BTX)-induced neuro-muscular junctional block and its resultant hypotrophy of masticatory muscles would produce mandibular growth disturbances in size and shape. Ten male cynomolgus monkeys were divided into three groups: group I (control; n = 3), group II (unilateral BTX; n = 4), and group III (bilateral BTX; n = 3). The unilateral or bilateral muscular hypotrophy of major masticatory closing muscles was induced by synchronous BTX application to masseter, medial pterygoid, and temporal muscle. Mandibular growth was tracked by linear, angular, area and volume measurements using three-dimensional (3D) computed tomography imaging before BTX treatment and after 3 and 6 months. After unilateral hypotrophy of masticatory muscles in group II, vertical growth deficiency was prominent on the BTX side, with compensatory overgrowth on the control side. The bilateral muscular hypotrophy in group III also showed smaller ramal height and width than that of control (group I) and control side (group II). Moreover, ramal sagittal angles (posterior tilt) increased on the BTX side of both groups II and III, but coronal angles (lateral tilt) did so on the BTX side of group II, resulting in asymmetry. The results confirmed our hypothesis that functional activity of masticatory closing muscles is closely related to mandibular growth in size and shape of juvenile nonhuman primates. In addition, the focused growth disturbances on the ramal height and posterior-lateral tilt suggested the possible role of masticatory closing muscles for ramal vertical and angular growth vector of the mandible.https://www.frontiersin.org/article/10.3389/fphys.2019.00496/fullmasticatory musclescraniofacialgrowthbotulinum toxincomputed tomographymandible |
| spellingShingle | Hak-Jin Kim Hye-Jin Tak Joo-Won Moon Sang-Hoon Kang Seong Taek Kim Jinquan He Zhenguo Piao Sang-Hwy Lee Mandibular Vertical Growth Deficiency After Botulinum-Induced Hypotrophy of Masticatory Closing Muscles in Juvenile Nonhuman Primates Frontiers in Physiology masticatory muscles craniofacial growth botulinum toxin computed tomography mandible |
| title | Mandibular Vertical Growth Deficiency After Botulinum-Induced Hypotrophy of Masticatory Closing Muscles in Juvenile Nonhuman Primates |
| title_full | Mandibular Vertical Growth Deficiency After Botulinum-Induced Hypotrophy of Masticatory Closing Muscles in Juvenile Nonhuman Primates |
| title_fullStr | Mandibular Vertical Growth Deficiency After Botulinum-Induced Hypotrophy of Masticatory Closing Muscles in Juvenile Nonhuman Primates |
| title_full_unstemmed | Mandibular Vertical Growth Deficiency After Botulinum-Induced Hypotrophy of Masticatory Closing Muscles in Juvenile Nonhuman Primates |
| title_short | Mandibular Vertical Growth Deficiency After Botulinum-Induced Hypotrophy of Masticatory Closing Muscles in Juvenile Nonhuman Primates |
| title_sort | mandibular vertical growth deficiency after botulinum induced hypotrophy of masticatory closing muscles in juvenile nonhuman primates |
| topic | masticatory muscles craniofacial growth botulinum toxin computed tomography mandible |
| url | https://www.frontiersin.org/article/10.3389/fphys.2019.00496/full |
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