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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Beneficial effects of benzodiazepine on masticatory muscle dysfunction induced by chronic stress and occlusal instability in an experimental animal study

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Nascimento, Glauce C. [1] ; Malzone, Bruno L. [1] ; Iyomasa, Daniela M. [2] ; Pereira, Yamba C. L. [1] ; Issa, Joao Paulo M. [1] ; Leite-Panissi, Christie R. A. [1] ; Watanabe, Ii-Sei [3] ; Iyomasa, Mamie M. [1] ; Fuentes, Ramon [4] ; Del Bel, Elaine [1] ; Dias, Fernando J. [4]
Total Authors: 11
[1] Univ Sao Paulo, Sch Dent Ribeirao Preto, Dept Basic & Oral Biol, Ribeirao Preto, SP - Brazil
[2] Univ Oeste Paulista, Presidente Prudente Med Sch, Dept Morphol, Presidente Prudente, SP - Brazil
[3] Univ Sao Paulo, Inst Biomed Sci, Dept Anat, Sao Paulo, SP - Brazil
[4] Univ La Frontera, Res Ctr Dent Sci CICO, Dent Sch, Dept Integral Dent, Temuco - Chile
Total Affiliations: 4
Document type: Journal article
Source: SCIENTIFIC REPORTS; v. 10, n. 1 MAY 29 2020.
Web of Science Citations: 0

Psychological stress and occlusal alteration are important etiologic factors for temporomandibular/masticatory muscular disorders. In particular, the exact physiologic mechanism underlying the relation by occlusal alteration and temporomandibular disorders remains unclear. Our purpose was to test the hypothesis that benzodiazepine therapy is able to prevent metabolic and vascular changes in the medial pterygoid muscle of rats under chronic stress after 14 days of unilateral exodontia. Adult Wistar rats were submitted to unpredictable chronic mild stress (10 days) and/or unilateral exodontia and their plasma and medial pterygoid muscles were removed for analysis. A pre-treatment with diazepam was used to verify its effect on stress. The parameters evaluated included anxiety behavior, plasma levels of corticosterone, metabolic activity by succinate dehydrogenase, capillary density by laminin staining and ultrastructural findings by transmission electron microscopy. Occlusal instability induced anxiety-like behavior on elevated plus-maze test and diazepam administration blocked the appearance of this behavior. Unilateral exodontia promoted in the contralateral muscle an increase of oxidative fibers and capillaries and modification of sarcoplasmic reticulum. Chronic stress caused increased glycolytic metabolism, reduced capillary density and morphological changes in mitochondria on both sides. Association of both factors induced a glycolytic pattern in muscle and hemodynamic changes. Pharmacological manipulation with diazepam inhibited the changes in the medial pterygoid muscle after stress. Our results reveal a preventive benzodiazepine treatment for stress and occlusal instability conditions affecting masticatory muscle disorders. In addition, provide insights into the mechanisms by which chronic stress and exodontia might be involved in the pathophysiology of masticatory muscular dysfunctions. (AU)

FAPESP's process: 12/22128-6 - Effects of systemic stress associated with malocclusion medial pterygoid muscle and the brain
Grantee:Mamie Mizusaki Iyomasa
Support Opportunities: Regular Research Grants
FAPESP's process: 15/03053-3 - Evaluation of medial pterygoid muscle and brain structures related to orofacial nociception and emotional behavior in an animal model of chronic stress and masticatory hypofunction
Grantee:Glauce Crivelaro Do Nascimento
Support Opportunities: Scholarships in Brazil - Post-Doctoral