# 坏死（Necrosis）

- 器官 / 系统：牙齿 / 消化系统（tooth / alimentary-system）
- NTP 数据编号：ntp-0249
- 规范 URL：https://www.labsmart.cn/ntp/tooth-necrosis.html
- 中文图谱总页锚点：https://www.labsmart.cn/ntp-atlas.html#tooth-necrosis
- 原始出处：https://ntp.niehs.nih.gov/atlas/nnl/alimentary-system/tooth/Necrosis
- 授权：美国联邦政府作品，公有领域；引用请标注 NTP Nonneoplastic Lesion Atlas
- 适用说明：仅供科研使用，不用于临床诊断

## 一句话结论
牙髓中的细菌感染及其他损伤会诱发炎症反应，但与脑组织被颅骨包绕类似，牙髓被牙本质包绕限制了肿胀的程度。

## 病变描述（中文）
牙髓中的细菌感染及其他损伤会诱发炎症反应，但与脑组织被颅骨包绕类似，牙髓被牙本质包绕限制了肿胀的程度。炎症时发生的肿胀可导致牙髓内压力显著升高，从而抑制血流。此外，由于牙根尖是血管的唯一入口，牙髓内 collateral 血管的形成受到抑制。牙髓内压力升高或血管闭塞（如血栓形成）所致的血流减少，通常导致牙髓缺血性坏死和牙齿死亡。

## 诊断与分级建议（NTP 共识，中文）
当牙齿的大部分受累且牙内多个组织发生坏死时，应诊断牙齿坏死并分级。若牙内1或2个特定部位受累（如成釉细胞、成牙本质细胞、牙髓），而牙齿的大部分未受累，则应在诊断中注明受累部位。任何伴随的炎症，仅当其被认为与坏死无关（即属于原发性病变）或其严重程度足以需要单独诊断时，才应予以诊断。

## 英文原文 · Comment
Bacterial infection and other injuries in the tooth pulp induce an inflammatory response, but similar to the brain’s enclosure within the calvarium, the tooth pulp’s enclosure within the dentin limits the amount of swelling. The swelling that occurs with inflammation can result in markedly increased pressure in the tooth pulp, which inhibits blood flow. Additionally, the intrapulpal formation of collateral blood vessels is inhibited because the apex of the tooth is the sole entry point for blood vessels. The decreased blood flow due to increased intrapulpal pressure or vascular occlusion (e.g., thrombosis) generally results in ischemic necrosis of the pulp and death of the tooth.

## 英文原文 · Recommendation
Necrosis of the teeth should be diagnosed and graded if the majority of a tooth is affected and multiple tissues within the tooth are necrotic. If 1 or 2 particular sites in the tooth are affected (e.g., ameloblast, odontoblast, pulp), and the majority of the tooth is unaffected, then the site(s) should be included in the diagnosis. Any associated inflammation should be diagnosed only if it is considered to be unrelated to the necrosis (i.e., is a primary lesion) or if it is severe enough to warrant a separate diagnosis.

## 配图
- https://www.labsmart.cn/ntp-atlas-images/ntp_0207.jpg
- https://www.labsmart.cn/ntp-atlas-images/ntp_0201.jpg

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