24. 因牙本質發育不良,造成牙髓角處裂縫(pulp horn cleft),致細菌入侵牙髓,而形成非齲性根尖病變和牙齦瘻管,是下列何者之口腔特徵?(A) hypervitaminosis A(B) vitamin D-deficient rickets(C) vitamin D-resistant rickets(D) hypophosphatasia