【用戶】yun
【年級】高三下
【評論內容】(p.3) In general, the rods are aligned perpendicularly to the DEJ and the tooth surface in the primary and permanent dentitions except in the cervical region of permanent teeth, where they are oriented outward in a slightly apical direction.(B) X,大多牙釉稜柱(enamel rod)與牙齒表面和牙本質牙釉質交界(DEJ)互相垂直,除恆牙齒頸部略向根尖方向之外