乳牙外形课件何07-1.pptVIP

Anatomy of deciduous teeth Anatomy of deciduous teeth Anatomy of deciduous teeth Anatomy of deciduous teeth Anatomy of deciduous teeth 乳切牙外形 Tooth is described from crow and root Crown is described from 5 aspects Labial or buccal surface Lingual surface Mesial surface Distal surface (Proximal surface) Incisal (or occlusal) surface (ridge or margin) 上颌乳中切牙 2.牙根 ( Root) ■ 单根，宽扁，唇面宽于舌面 ■ 根长为冠长2倍 ■ 根尖1／3弯向唇侧，偏远中 (宽冠宽根为重要解剖标志) 上颌乳侧切牙 下颌乳中切牙 下颌乳侧切牙 The ?mandibular deciduous lateral ?incisor The ?mandibular deciduous lateral ?incisor ■ 近、远中缘对称，近中与远中切角较锐 ■ 切嵴较直，唇颈嵴较突 The mandibular deciduous central incisor (2)舌面(lingual Surface) ■ 舌面凹陷 ■ 边缘嵴窄而突(incisal,mesial and distal ridge) ■ 舌面舌窝明显 ■舌面隆突不大 The mandibular deciduous central incisor (3)邻面(Proximal surface) ■ 邻面呈三角形 The mandibular deciduous central incisor (4)切缘(Incisor ridge) ■ 切缘较薄，切嵴位于牙长轴上 The mandibular deciduous central incisor (4)切缘(Incisor ridge) ■ 唇颈嵴、舌面隆突均较突 The mandibular deciduous central incisor 2.牙根 ■ 单根，较细长 ■ 根长度约为冠长的2倍 ■ 根尖部偏向唇侧 ? The mandibular deciduous central incisor ? 下颌乳侧切牙的牙冠较下颌乳中切牙为大 1.牙冠(Dental crown) (1)唇面(labial?surface) ■唇面略突 ■近中缘长，远中缘短 ■切嵴自近中向远中舌侧斜行 The ?mandibular deciduous lateral ?incisor ■近中切角为一小圆角 ■远中切角为一大圆钝角 (2)舌面(Lingual ?Surface) ■ 舌面外形似唇面 ■ 舌面凹陷比中切牙明显 ■ 舌面隆突较大 ■ 近、远中边缘嵴明显 ■ 舌窝较深 The ?mandibular deciduous lateral ?incisor (3)邻面(Proximal surface) ■邻面显三角形(a wedge) ■ 接触区在切1/3 The ?mandibular deciduous lateral ?incisor 2.牙根 ? ■ 牙根为单根 ■长度比下颌乳中切牙稍长 ■自唇面向舌侧缩窄 ■根尖微向唇侧，略微斜向远中 The ?mandibular deciduous lateral ?incisor Anatomy of the deciduous canine 上颌乳尖牙(The maxillary deciduous canine) 下颌乳尖牙(The mandibular deciduous canine) ■ 上颌乳尖牙牙冠外形与上颌恒尖牙相似，但体积明显缩小，唇、舌轴嵴较为突出 上颌乳尖牙 1.牙冠(Dental crown) (1)唇面(Labial?surface) ■与上颌恒尖牙相似 ■牙尖长大，约占牙冠长度的一半 ■牙尖偏远中 Anatomy of the deciduous canine ■ 有5条缘, (the mesial and distal oblique?margin, ?mesial and distal margin, the distal margin and cervical margin) ■ 近中斜缘长于远中斜缘 ■ 唇轴嵴很突，颈嵴最突，颈缘弧度很小 ，几乎平直