牙齿萌出ppt课件

牙齿的发育萌出EruptionandSheddingofTeeth,1,2,3,MixedDentition:Presenceofbothdentitions,FigurefromTenCatesOralHistology,Ed.,AntonioNanci,6thedition,4,牙齿的发生时间,胎龄3周原始口腔胎龄6周牙板(dentallamina)胎龄7周20个乳牙牙胚（toothgerm)胎龄4月第一恒磨牙胎龄5、6月恒切牙、尖牙出生时第一前磨牙78月第二前磨牙89月第二恒磨牙4岁左右第三恒磨牙,5,1.生长期：特点是牙胚组织的形成，是组织学的变化2.钙化期：特点是钙盐沉积，基质逐渐变硬，通过X线片可以看到牙齿钙化的全过程。Nolla把X线片上的恒牙钙化过程分成10个阶段。,6,7,8,牙齿萌出,骨内萌出,临床萌出,3.萌出期：特点是牙齿开始向面而移动，直到建立关系发挥咀嚼功能。牙齿萌出不是发育结束，正常情况下，牙齿进入口腔时，牙根仅发育到根长的2/3，所以，牙齿萌出后牙根继续发育，据临床观察，乳牙根在它萌出后大约11.5年牙根可以发育完成，而恒牙需要13年才完成。,9,乳牙早且快，用月来计算：688（6，812）1216（1216）1622（1622）30独一份,10,恒牙晚且慢，用年来计算：切牙789（78、89）尖牙113（1113）双尖10112（1011、1112）磨牙6岁就见面二磨114（1114）1825磨牙全,11,（二）牙齿萌出顺序,12,13,乳牙的萌出小结,时间：6月-2岁半个体差异大顺序：ABDCE差异：AABB和ABAB,14,Source:/itc/hs/dental/d9903/lectures/lecture4.pdf,15,16,恒牙,17,恒牙的萌出小结,时间：6岁12、13岁个体差异大顺序：上：6124357861245378下：61234578,18,EssentialsofOralHistologyandEmbryology.JamesAvery,2ndedition,19,Source:/itc/hs/dental/d9903/lectures/lecture4.pdf,20,21,FigurefromTenCatesOralHistology,Ed.,AntonioNanci,6thedition,22,23,24,FigurefromTenCatesOralHistology,Ed.,AntonioNanci,6thedition,25,Stagesoftootheruption,EssentialsofOralHistologyandEmbryology.JamesAvery,2ndedition,26,EssentialsofOralHistologyandEmbryology.JamesAvery,2ndedition,27,5months,Atbirth,1year,2years,3.5years,4.5years,Sheddingofmandibularincisor,FigureSource:Dr.SandraMeyers,28,Thesix/fourruleforprimarytoothemergenceFourteethemergeforeach6monthsofage,6months:4teeth(lowercentrals&uppercentrals)12months:8teeth(1.+upperlaterals&lowerlaterals)18months:12teeth(2.+upper1stmolars&loer1stmolars)24months:16teeth(3.+uppercanines&lowercanines)30months:20teeth(4.+lower2ndmolars&upper2ndmolars),Source:/itc/hs/dental/d9903/lectures/lecture4.pdf,29,Summary,By5monthsinutero,allcrownsstartedcalcificationBy1yearold,allcrownscompletedformationBy2.5years,allprimaryteetheruptedBy4yearsold,allprimaryteethcompletedrootformation,Source:/itc/hs/dental/d9903/lectures/lecture4.pdf,30,Therulesof“Fours”forpermanenttoothdevelopment(3rdmolarsnotincluded),Atbirth,four1stmolarshaveinitiatedcalcificationAt4yearsofage,allcrownshaveinitiatedcalcificationAt8years,allcrownsarecompletedAt12years,allcrownsemergeAt16years,allrootsarecomplete,Source:/itc/hs/dental/d9903/lectures/lecture4.pdf,31,Rulesof“sixes”indentaldevelopment,6weeksoldinutero:beginningofdentaldevelopment6monthsold:emergenceofthefirstprimarytooth6yearsold:emergenceoffirstpermanenttooth,Source:/itc/hs/dental/d9903/lectures/lecture4.pdf,32,ProblemsofPrimaryToothEruption,NatalandNeonatalTeeth,33,RetainedPrimaryteeth,34,Submergedprimaryteeth,Hyperorsupraeruption,35,Ankylosis,Source:Coloratlasofclinicaloralpathology.