HeHong-wenDept.ofOralAnatomyandPhysiology乳牙外形乳牙外形乳牙有乳牙有20颗颗乳牙外形特点乳牙外形特点(1)乳牙体积小，牙冠短而宽，乳白色乳牙体积小，牙冠短而宽，乳白色 Anatomyofdeciduousteeth(2)乳牙颈部缩窄，唇颈嵴、颊颈嵴显突出乳牙颈部缩窄，唇颈嵴、颊颈嵴显突出Anatomyofdeciduousteeth(3)合面缩窄，冠根分明合面缩窄，冠根分明Anatomyofdeciduousteeth牙牙(3)乳前牙宽冠窄根乳前牙宽冠窄根Anatomyofdeciduousteeth(3)上颌乳中切牙为宽冠宽根，根尖弯向唇侧上颌乳中切牙为宽冠宽根，根尖弯向唇侧deciduouscentralincisorAnatomyofdeciduousteethAnatomyofdeciduousteeth(4)上颌乳尖牙的近中牙尖嵴长于远中牙尖嵴，是乳尖牙上颌乳尖牙的近中牙尖嵴长于远中牙尖嵴，是乳尖牙和恒尖牙中唯一牙尖偏向远中者和恒尖牙中唯一牙尖偏向远中者Anatomyofdeciduousteeth(5)下颌第二乳磨牙三个颊尖等大下
