Oliveira F S, Canola J C, Oliveira P T, Pécora J D, Capelli A
Animal Clinics and Surgery Department, Faculty of Veterinary, São Paulo State University (UNESP), Jaboticabal, SP, Brazil.
Anat Histol Embryol. 2007 Oct;36(5):371-4. doi: 10.1111/j.1439-0264.2007.00768.x.
The microscopic description of the teeth of pacas (Agouti paca) bred in captivity was developed for providing biological data on one of the largest American wild rodents, as not many references exist in the literature about this species. Two newborn males, two adult males (9 and 72 months old), one newborn female and two adult females (30 and 54 months old) were used after death due to fights, neonatal cannibalism or unknown causes. Animals were radiographed, and their teeth were extracted and put on an acrylic resin block, cut on a diamond-like disc microtome and diaphanized. It was noted that enamel surrounds the coronary dentine and projects to the root region, besides being present as internal laminae, arranged in a parallel way and in the vestibulolingual direction. The dentine is located between the enamel laminae and surrounds the pulp horns. The cementum is located internal to the enamel laminae. From scanning electronic microscopy, we find that the enamel is the outer element on the vestibular surface, and it is in direct contact with the dentine. On the lingual surface, the cementum and dentine are the outer elements.
对人工饲养的刺豚鼠（Agouti paca）牙齿进行微观描述，旨在为这种美洲最大的野生啮齿动物之一提供生物学数据，因为关于该物种的文献参考并不多。两只新生雄性、两只成年雄性（9个月和72个月大）、一只新生雌性和两只成年雌性（30个月和54个月大）在因打斗、新生仔兽自相残杀或不明原因死亡后被用于研究。对动物进行了X光检查，然后提取它们的牙齿，固定在丙烯酸树脂块上，用类似钻石的圆盘切片机切割并进行透明处理。结果发现，牙釉质围绕着冠状牙本质并延伸至牙根区域，此外还以内部薄片的形式存在，这些薄片呈平行排列，沿前庭舌侧方向分布。牙本质位于牙釉质薄片之间并围绕着牙髓角。牙骨质位于牙釉质薄片内部。通过扫描电子显微镜观察发现，在前庭表面，牙釉质是最外层结构，与牙本质直接接触。在舌侧表面，牙骨质和牙本质是最外层结构。
