1. 有關牙齒發育與解剖的敘述,下列何者正確?
A.當牙本質形成(dentinogenesis )啟動後牙濾泡(dental follicle )會形成牙髓(dental pulp )
B. 赫威氏上皮根鞘(Hertwig's epithelial root sheath )會決定牙根管的大小與形狀
C. 側根管區(lateral canals )在根管中 1/3(middle third )最常出現
D.牙本質小管(dentinal tubule )數目由牙髓區(pulp )往周邊(periphery )漸漸減少