title: Ultrastructural characteristics of the gerbil pterygoid medial muscle after experimental occlusal alteration.
abstract: Ten male young adult gerbils Meriones unguiculatus weighing 55g were divided in two groups: experimental (n=5) animals submitted to exodontia of the left upper molars, and sham-operated were used as control (n=5) group. The aim of the present study was to investigate the ultrastructural effects of occlusal alteration induced by unilateral exodontia on medial pterygoid muscle. After 60 days, the animals were sacrificed by perfusion intracardially with a modified Karnovsky solution after anesthetized with overdose of urethane (3g/kg i.p.). The small samples of this muscle were fixed in 2.5% glutaraldehyde solution and post-fixed in 1% buffered osmium tetroxide solution, dehydrated in ascending concentration of ethanol, and embedded in Spurr resin. Several micrographs data showed that in this period of time, the unilateral teeth extraction was able to induce modifications on the medial pterygoid muscle fibers and capillaries at ultrastructural levels as compared to control muscles and to the ones in the contralateral side of the experimental animals. Ultrastructural changes suggest that injury was greater in the hypofunctional muscle, ipsilateral to teeth extraction.
authors.affiliation: Faculty of Dentistry of Ribeirão Preto, University of São Paulo, São Paulo, Brazil. mamieiyo@forp.usp.br
authors.forename: Mamie Mizusaki
authors.initials: MM
authors.lastname: Iyomasa
authors.forename: João Paulo Mardegan
authors.initials: JP
authors.lastname: Issa
authors.forename: Márcia Consentino Kronka
authors.initials: MC
authors.lastname: Sosthines
authors.forename: Ana Maria De
authors.initials: AM
authors.lastname: Oliveira
authors.forename: Maria Bernadete Sasso
authors.initials: MB
authors.lastname: Stuani
authors.forename: Aracy Akiko
authors.initials: AA
authors.lastname: Motoyama
authors.forename: Ii-Sei
authors.initials: IS
authors.lastname: Watanabe
mesh_terms: D000818:Animals; D005849:Gerbillinae; D008297:Male; D046529:Microscopy, Electron, Transmission; D008963:Molar; D011626:Pterygoid Muscles / Q000648:ultrastructure*; D014081:Tooth Extraction