Abstract：
Reports of compound odontomas in rats are very rare. A 14-month-old adult male Sprague Dawley rat was found to have a hard mass associated with the caudal aspect of the left mandible. After 2 weeks of observation, the rat was euthanized due to the mass growing significantly in size and the rat losing >20% of its body weight. Grossly, the mass was well-circumscribed, 3.7 × 3 × 1.2 cm, hard and heterogeneously coloured white, tan and red. The mass was restricted to the mandibular bone and did not involve surrounding subcutaneous tissue. On cut surface, the mass was a similar colour and brittle. Histologically, there were numerous proto-teeth embedded in ossified stroma. Each proto-tooth had a central mesenchyme pulp surrounded by columnar odontoblasts and dentine matrix. The dentine was often bordered by enamel matrix, which was occasionally bounded by ameloblasts. These histological findings were consistent with a compound odontoma. This is the first report of a spontaneous compound odontoma in the caudal mandible of a rat.
摘要：
关于大鼠复合牙瘤的报道非常罕见。发现一只14个月大的成年雄性SpragueDawley大鼠的硬块与左下颌骨的尾部有关。观察2周后,对大鼠实施安乐死,因为质量显著增大,并且大鼠失去>20%的体重。严重的,质量是有界限的，3.7×3×1.2厘米，坚硬且不均匀的白色，棕褐色和红色。肿块仅限于下颌骨，不涉及周围的皮下组织。在切割表面上，质量是相似的颜色和脆性。组织学上,骨化的基质中嵌入了许多原始牙齿。每颗原牙的中央间充质髓被柱状成牙本质细胞和牙本质基质包围。牙本质通常以釉质基质为边界，偶尔被成釉细胞包围。这些组织学发现与复合牙瘤一致。这是大鼠尾下颌骨中自发性复合牙瘤的首次报道。
