# 牙齿发育不良（Dental Dysplasia）

- 器官 / 系统：牙齿 / 消化系统（tooth / alimentary-system）
- NTP 数据编号：ntp-0260
- 规范 URL：https://www.labsmart.cn/ntp/tooth-dental-dysplasia.html
- 中文图谱总页锚点：https://www.labsmart.cn/ntp-atlas.html#tooth-dental-dysplasia
- 原始出处：https://ntp.niehs.nih.gov/atlas/nnl/alimentary-system/tooth/DentalDysplasia
- 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
牙齿发育不良（dental dysplasia）（Figure 1、Figure 2、Figure 3、Figure 4）是一种常见的牙齿慢性退行性改变，主要累及切齿，可发生于创伤或炎症之后。

## 病变描述（中文）
牙齿发育不良（dental dysplasia）（Figure 1、Figure 2、Figure 3、Figure 4）是一种常见的牙齿慢性退行性改变，主要累及切齿，可发生于创伤或炎症之后。它代表受损或移位牙源性组织的异常发育，其特征为牙本质、牙骨质和类骨质（来自牙槽骨）的异常沉积。它可以是单侧或双侧的。具有高冠齿列（hypsodont dentition）的物种，其切齿特别容易发生发育不良性改变，因为形成器官在动物整个生命周期中持续存在。啮齿类的上切齿比下齿更易遭受创伤性损伤，因为颅骨为牙齿提供的支持基础较不稳定。上颌切齿正常功能所需的背侧骨性支持是坚固的，但牙齿的侧方支持主要来自软组织，易受创伤性损伤和移位。当切齿受伤时，牙器官的残余部分可能继续尝试形成牙齿，尽管由于细胞或组织移位而表现异常。此外，通常还存在类似骨折愈合的一般性愈合反应，这常常解释此类病变中骨、牙本质或骨牙本质（osteodentin）的增多。在某些动物中，发育不良的牙齿物质在正常牙齿位置邻近形成大的实性团块。牙本质、牙骨质和类骨质并不总能轻易相互区分。在牙齿团块相关部位观察到牙周脓肿，部分伴有向鼻腔的穿孔和严重鼻炎。饲喂粉状饲料（减少了切齿的正常磨损）以及反复修剪过度生长的切齿，被认为促成了该病症的发生率。牙齿发育不良必须与牙瘤（odontoma）相鉴别。“牙瘤”一词指的是大多数权威认为的类似肿瘤的错构瘤性畸形。牙瘤的特征是牙器官的增生性冗余，进展至釉质和牙本质形成的阶段。大小和细胞密度/增殖活性是区分牙瘤与牙齿发育不良的标准。一般而言，牙齿发育不良类似于尝试性修复（令人联想到伴有大量致密骨/骨牙本质的骨折骨痂），并带有一些残留的活跃牙器官组织。“牙瘤”的诊断保留用于较大、细胞更丰富的团块，这些团块似乎增殖超出了发育中牙齿或牙齿骨折尝试性修复的预期范围。由于膨胀，牙瘤可以是破坏性团块。

## 诊断与分级建议（NTP 共识，中文）
牙齿发育不良应当根据发育不良牙齿的数量和大小进行诊断和分级。

## 英文原文 · Comment
Dental dysplasia ( Figure 1 , Figure 2 , Figure 3 , and Figure 4 ) is a common, chronic, degenerative change of the teeth, mainly the incisors, that can occur after trauma or inflammation. It represents abnormal development of injured or displaced odontogenic tissues and is characterized by abnormal deposits of dentin, cementum, and osteoid (from the alveolar bone). It can be unilateral or bilateral. The incisors of species with hypsodont dentition are particularly prone to dysplastic changes because of the persistence of the formative organ throughout the animal’s life. The upper incisors of rodents are more susceptible to traumatic injury than the lower teeth because the bones of the skull provide a less stable base of support. The dorsal bony support of the maxillary incisors, which is needed for normal function, is solid, but the lateral support of the teeth is derived mainly from the soft tissue and is susceptible to traumatic injury and displacement. When an incisor is injured, what remains of the dental organ may continue to attempt tooth formation, although it is abnormal because of cell or tissue displacement. In addition, there is often a general healing response, similar to fracture healing, and this often accounts for the increased bone, dentin, or osteodentin in these lesions. In some animals, dysplastic dental material forms large solid masses adjacent to the normal tooth position. Dentin, cementum, and osteoid cannot always be readily distinguished from one another. Periodontal abscesses, some with perforation into the nasal cavities and severe rhinitis, were observed in association with the dental masses. Feeding powdered ration, which reduced the normal wearing of the incisors, and repeated clipping of overgrown incisors were believed to contribute to the incidence of this condition. Dental dysplasia must be differentiated from odontoma. The term "odontoma" refers to what most authorities consider a hamartomatous malformation that resembles a neoplasm. Odontomas are characterized by proliferative redundancies of the dental organ that progress to the stage of both enamel and dentin formation. Size and cellularity/proliferative activity are criteria for differentiating odontomas from dental dysplasia. In general, dental dysplasia resembles attempted repair (reminiscent of a fracture callus with abundant dense bone/osteodentin) with some residual active dental organ tissue. The diagnosis of "odontoma" is reserved for larger, more cellular masses that appear to be proliferating beyond what one would expect for a developing tooth or attempted repair of a tooth fracture. Because of expansion, odontomas can be destructive masses.

## 英文原文 · Recommendation
Dental dysplasia should be diagnosed and graded based on the number and size of the dysplastic teeth.

## 配图
- https://www.labsmart.cn/ntp-atlas-images/ntp_0186.jpg
- https://www.labsmart.cn/ntp-atlas-images/ntp_0191.jpg

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