Peculiar characteristics of the insertion area of the masseter muscle in rats. Scanning electron microscopic study.
The structure of the bone surface of the insertion area of the masseter muscle was studied in 20 albinus Wistar rats. Specimens were fixed in a modified Karnovsky solution and treated according to the technique described by LESTER et alii and examined in a JEOL scanning electron microscope, JSM-P15. The results showed that the insertion area of the masseter muscle of rats presents a smooth surface covered by thick layers of calcified collagen fibers. In adjacent areas of the lower edge of the mandibular angle an irregular surface with bone reabsorption and foraminae was observed. The vascular foraminae measure from 30 to 50 microns in diameter and the distance between them ranges from 200 to 460 microns. Osteocyte lacunae were seen at the surface and their measures range from 18 to 25 microns in diameter, which were surrounded by collagen fiber bundles of longitudinal disposition.
Kao
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Watanabe
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Fonoff
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D000818:Animals; D008334:Mandible / Q000033:anatomy & histology*; D008406:Masseter Muscle / Q000033:anatomy & histology*; D008410:Masticatory Muscles / Q000033:anatomy & histology*; D051381:Rats; D011919:Rats, Inbred Strains