成釉细胞萎缩Ameloblast Atrophy · 牙齿 · 消化系统 · NTP ntp-0252
诊断要点：无论何时出现，成釉细胞萎缩均应作出诊断，并根据细胞萎缩程度和受累成釉细胞数量进行分级。
病变描述
成釉细胞（ameloblast）（Figure 1、Figure 3，箭头）是负责釉质生成的细胞。成釉细胞的局灶性（focal）萎缩可导致釉质发育不全，但由于组织切片制备中的釉质脱钙会去除釉质，因此难以评估。釉质缺失在受累牙齿的大体检查中可能呈现特征性的褐色变色。成釉细胞萎缩（Figure 2、Figure 4，箭头）可由化学暴露引起，最显著的是氟化物毒性。成牙本质细胞也可受累，但成釉细胞似乎更为敏感。萎缩的特征是单个成釉细胞因细胞质减少和细胞核变小而缩短（Figure 4，箭头）。萎缩可导致成釉细胞鳞状化生，其特征为成釉细胞柱状层丧失并被鳞状上皮取代（见 Tooth - Ameloblast - Metaplasia, Squamous）。
诊断与分级建议（NTP 共识）
无论何时出现，成釉细胞萎缩均应作出诊断，并根据细胞萎缩程度和受累成釉细胞数量进行分级。相关链接：Tooth - Ameloblast - Metaplasia, Squamous
图谱
英文原文
展开 NTP 官方英文描述与建议
Comment：
Ameloblasts ( Figure 1 and Figure 3 , arrows) are the cells responsible for enamel production. Focal atrophy of ameloblasts can lead to enamel hypoplasia, which is difficult to assess because enamel decalcification removes the enamel in tissue sections. The loss of enamel may impart a characteristic brownish discoloration on gross examination in affected teeth. Ameloblast atrophy ( Figure 2 and Figure 4 , arrows) can be caused by chemical exposure, most notably fluoride toxicity. Odontoblasts can also be affected, but ameloblasts appear to be more sensitive. Atrophy is characterized by shortening of individual ameloblasts ( Figure 4 , arrow) due to decreased amounts of cytoplasm and smaller nuclei. Atrophy can lead to squamous metaplasia of ameloblasts, characterized by loss of the columnar layer of ameloblasts with replacement by squamous epithelium (see Tooth - Ameloblast - Metaplasia, Squamous ).
Recommendation：
Whenever present, ameloblast atrophy should be diagnosed and graded based on the degree of cellular atrophy and the number of ameloblasts affected. Related Links: Tooth - Ameloblast - Metaplasia, Squamous
来源与引用
原始条目：https://ntp.niehs.nih.gov/atlas/nnl/alimentary-system/tooth/Ameloblast-Atrophy
图谱总目录：NTP Nonneoplastic Lesion Atlas。 内容属美国联邦政府作品（公有领域），可引用；引用时请标注来源。
建议引用格式：NTP Nonneoplastic Lesion Atlas. Ameloblast Atrophy (tooth). LabSmart 中文版：
https://www.labsmart.cn/ntp/tooth-ameloblast-atrophy.html
中文图谱总页（可展开对照全部 595 条）：https://www.labsmart.cn/ntp-atlas.html#tooth-ameloblast-atrophy