牙发育异常-上海交通大学医学院精品课程

非龋性疾病,non carious disease,牙外伤(injury of teeth),牙发育异常(developmental abnormality of teeth),牙体慢性损伤（chronic injury of teeth),牙本质过敏症（dentine hypersensitivity),牙发育异常,developmental abnormality of teeth,主要内容 Summary,牙结构异常 Abnormalities of histodifferentiation牙形态异常 Abnormalities of morphodifferentiation牙数目异常 Disturbances in number of teeth牙萌出异常 Disturbances in germination of teeth,钟状期造釉器(enamel organ in bell stage),dental papilla,stellate reticulum,enamel,dentine,external enamel epithelium,牙结构异常 Abnormalities of histodifferentiation,釉质发育不全 enamel hypoplasia氟牙症 dental fluorosis四环素牙 tetracycline stained teeth遗传性牙本质发育不全 hereditary dentinogenesis imperfecta先天性梅毒牙 congenital syphilitic teeth,釉质发育不全 enamel hypoplasia,定义 definition,牙齿发育期间，由于全身疾患、营养障碍或乳牙的严重的根尖周感染所导致的釉质的结构异常。(enamel abnormalities of histodifferentiation result from systematic disease, nutrition deficiency or severe apical affection of deciduous dentition during teeth formation),釉质发育不良：釉质基质形成障碍(dyspoiesis of enamel matrix),釉质矿化不良：基质形成正常，但矿化不良 (hypomineralization),釉质实质缺损(with enamel loss),釉质无实质缺损(without enamel loss),enamel agenesis,enamel hypocalcification,病因 Aetiology,营养障碍 nutrition deficiency内分泌失调 incretion disorder婴儿、母体疾病 infant & maternal disease局部因素 localized causes,釉质发育不全（enamel hypoplasia),病因（Aetiology),婴儿、母体疾病 infant & maternal disease,出生前 Prenatal新生儿 Neonatal婴儿 Postnatal,出生前 Prenatal,感染（infection)风疹(rubella)、梅毒(syphilis)母亲的代谢性疾病（maternal systemic disease),新生儿 Neonatal,新生儿溶血性疾病（haemolytic disease of the newborn)低钙血症 （hypocalcaemia)早产儿/晚产儿（premature birth/prolonged labour),婴儿 Postnatal,感染尤其是重症病毒感染（severe childhood infections especially the viral exanthemata)慢性疾病先天性心脏病、胃肠道疾病、内分泌疾病（chronic diseases in childhood,e.g. congenital heart disease, gastrointestinal and endocrine diseases)营养不良维生素D缺乏（nutritional deficiency, e.g. vitamin D)肿瘤化疗（cancer chemotherapy)氟中毒（excess fluoride ions),局部因素 localized causes,感染（Infection)创伤 （Trauma)放疗 (Radiotherapy),临床表现 clinical features,轻症 mild type重症 severe type,轻症 mild type,釉质形态基本完整（smooth-surface enamel)仅有色泽和透明度的改变 （white, opaque spots, brown-stained after eruption),重症 severe type,带状(横沟状)缺陷 (horizontal grooves in the enamel surface)窝状缺陷 （pits in the enamel surface)釉质变薄 （general reduction in the thickness of the whole enamel),特点：对称发生 (symmetrical),例外？（exception),对称发生 (symmetrical),提示 Note,累及 631136 提示致病因素1岁以内 6321 1236（damage occur at age 1)累及2 2 提示致病因素在出生后第2年（damage occur at age 2)累及754457 提示致病因素在23岁以后 754457 (damage occur at age 2-3),特纳牙 Turner teeth,乳牙的感染、创伤导致恒牙的造釉细胞的损伤（infection or trauma related to the deciduous predecessor resulting in damage to the ameloblasts of the permanent successor)釉质呈黄色或棕色（yellowish or brownish pigmentation of the enamel)表面凹陷、不规则(pits and irregularity of the surface) 牙冠小(the smaller crown than normal),治疗 Therapy,（略）,氟牙症,Dental Fluorosis,定义definition,又称氟斑牙或斑釉牙，主要是在牙齿发育矿化期，摄入过量的氟所引起的釉质发育不全、矿化不全。(ingestion of excessive fluoride during teeth formation result in enamel hypoplasia or hypocalcification),病因Aetiology,摄入过量的氟离子（ingestion of excess fluoride ions） 饮水含氟量，正常为1ppm（1 part per million of fluoride in the drinking water) 食物中的氟化物(fluoride in diet)损害釉质发育期牙胚的造釉细胞（damage ameloblasts during the tooth formation)造成釉质矿化不良，色素沉着（result in hypomineralized enamel & pigmentation),机理 Mechanism,磷酸酯（phospholipid)无机磷酸盐（inorganic phosphate),碱性磷酸酶（Alkali phosphatase）,抑制(inhibition),骨、牙齿的重要组成部分,焦磷酸和ATP骨基质矿化(mineralization),氟浓度增高（fluoride increasing),结果（result)：釉质矿化不良（hypomineralized enamel),造釉细胞（ameloblast),高氟导致氟牙症（excess fluoride result in dental fluorosis),？,(pyrophosphoric acid and Adenosine Triphosphate),机理 Mechanism,在牙齿发育期间，过量摄入的氟才会导致氟牙症（dental fluorosis result from a high intake during the period of tooth formation)氟不易通过胎盘屏障，乳牙一般不受累（Placenta barrier can resist fluoride, dental fluorosis seldom appear in deciduous dentition)提示：67岁以前，高氟摄入易患氟牙症 ！ （Ingestion excess fluoride no more than 6-7 age is prone to high prevalence),机理 Mechanism,氟牙症（dental fluorosis),临床表现 clinical features,在同一时期萌出的釉质上有白垩色到褐色的斑块(fluoride opacities occur symmetrically around the arch characterized by faint white flecking of the enamel, white patches or striations)严重者还并发釉质的实质缺损。(in severe cases may associate with loss of the normal tooth form)临床上常按其轻、中、重度而分为白垩型（轻度)、着色型（中度）和缺损型（重度）3种类型。,临床表现 clinical features,多见于恒牙，发生在乳牙者甚少，程度亦较轻。这是由于乳牙的发育分别在胚胎期和乳婴期，而胎盘对氟有一定的屏障作用。因此，氟牙症一般见于恒牙，但如氟摄人量过多，超过胎盘筛除功能的限度时，也能不规则地表现在乳牙上。(mainly found in the permanent dentition, but the deciduous teeth may be involved in severe cases and in areas of endemic fluorosis)对摩擦的耐受性差，但对酸蚀的抵抗力强。(high acid-resist, rapid loss by abrasion and attrition)严重的慢性氟中毒(severe cases),临床表现 clinical features,分类 Classification,治疗Therapy,脱色（bleaching)复合树脂（composite resin) （略）,脱色（bleaching),四环素牙,tetracycline stained teeth,定义definition,在牙齿的发育矿化期，服用的四环素族药物，结合到牙组织内，造成的牙齿的染色(discoloration of teeth resulting from deposits of tetracycline ingestion during tooth development)。,病因 Aetiology,在牙的发育矿化期（妊娠期和婴幼儿8岁以下），服用的四环素族药物，可被结合到牙组织内，使牙着色。(Tetracycline is administrated to pregnant females or to children under age of 8, it may be incorporated into the dentin of the developing teeth) 呈黄色，在阳光照射下则呈现明亮的黄色荧光，以后逐渐由黄色变成棕褐色或深灰色。(It produces a yellow discoloration, the teeth will fluoresce from a bright yellow to brown to gray with exposure to light)四环素可通过胎盘引起乳牙着色。(Permeate placenta to affect deciduous dentition),病因 Aetiology,四环素（tetracycline),四环素牙（tetracycline stained teeth ),恒牙（permanent dentition),乳牙（deciduous dentition),临床表现 clinical features,着色（stain)可伴有釉质发育不全 (enamel hypoplasia),临床表现 clinical features,治疗Therapy,复合树脂修复法 (composite resin)外脱色法 (bleaching)内脱色法 (intracoronal bleaching)？,复合树脂修复法 (composite resin),外脱色法 (bleaching),外脱色法 (bleaching),比较 comparison,遗传性牙本质发育不全,hereditary dentinogenesis imperfecta,病因 Aetiology,常染色体显性遗传(autosomal dominant)男、女患病率均等(equal frequency in males and females)乳、恒牙均可受累(affect both deciduous and permanent dentition),病理（Pathology),釉质结构基本正常，釉牙本质界失去小弧形的排列而呈直线相交(normal enamel structure, but amelodentinal junction(ADJ) is straight rather than scalloped) 牙本质形成较紊乱，牙本质小管排列不规则(the dentine contains a reduced number of tubules, many of which are wide and irregular) 由于不断较快地形成牙本质，髓腔消失 (exhibit premature closure of the pulp chamber and canals),临床表现 clinical features,牙冠呈微黄色半透明，光照下呈现乳光(translucent, opalescent amber-like appearance)釉质易从牙本质表面分离脱落使牙本质暴露，从而发生严重的咀嚼磨损(enamel is rapidly lost and the teeth then show marked attrition)X线片可见牙根短。牙萌出后不久，髓室和根管完全闭锁 (radiological examination shows short , blunt roots with partial or even total obliteration of the pulp chambers and root canals by dentine),临床表现 clinical features,治疗Therapy,义齿修复,先天性梅毒牙,congenital syphilitic teeth,病因 Aetiology,梅毒螺旋体侵犯牙胚（infection of the tooth germ by treponema pallidum ),临床表现 clinical features,半月形切牙 亦称哈钦森牙(Hutchinson teeth) 蕾状磨牙 (Pfluger teeth，Moon teeth),牙形态异常,Abnormalities of morphodifferentiation,几个疾病,过大牙、过小牙、锥形牙融合牙、双生牙、结合牙畸形中央尖 牙内陷釉珠,过小牙（ microdontia),过大牙(macrodontia),锥形牙(conic shaped teeth),融合牙(fused teeth)双生牙(geminated teeth)结合牙(concrescence teeth),融合牙(fused teeth),定义：两个正常的牙胚融合而成。(joining of two developing tooth germs)完全融合、不完全融合(completely or incompletely),双生牙(geminated teeth),定义：一个内向凹陷将一个牙胚不完全分开而成。(one tooth attempts to split in two)完全、不完全分开的牙冠(two crowns or one large partially separated crown)一个共同的牙根(sharing a single root),结合牙(concrescence teeth),定义：两个牙根发育完成的牙齿发生粘连而成。借助牙骨质结合牙本质各自分开(the union of two adjacent teeth by excessive cementum production),畸形中央尖,abnormal central cusp,病因 Aetiology,牙齿发育期，牙乳头向造釉器突起 ，形成釉质和牙本质(enamel and dentine formation for dental papilla protruding into enamel organ during tooth formation),临床表现 clinical features,多见于下颌前磨牙以第二前磨牙最多见（5 5）合面中央窝半圆形突起中央尖折断、磨损后，为圆形或椭圆形黑环，中央黑色小点（此处即使用极细的探针也不能探入）易造成牙髓感染、坏死，影响牙根尖的正常发育 喇叭形根尖,临床表现 clinical features,治疗Therapy,不作处理磨除脱敏(grind and desensitization)磨除备洞盖髓治疗(cavity preparation and pulp capping)根尖诱导成形术(apexification),牙内陷,dens invaginatus,牙发育时期，成釉器过度卷叠或局部过度增殖，深人到牙乳头中所致，牙萌出后，在牙面可出现一囊状深陷的窝洞（deep surface invagination of the crown of tooth lined by enamel and dentine),病因 Aetiology,临床表现clinical feature,畸形舌侧窝(lingual pit deformity)畸形舌侧尖(accessory palatal cusp)畸形根面沟(root groove deformity)牙中牙(dens in dente),多见于上颌侧切牙 (maxillary lateral incisor is most commonly affected ),畸形舌侧窝(lingual pit deformity) 易滞留菌斑、食物，造成牙髓病变(the defect cannot be kept free of plaque and bacteria, the tooth is prone to decay and subsequent pulpitis.),临床表现clinical feature,畸形舌侧尖(accessory palatal cusp) 舌隆突呈圆锥形