问题 单项选择题

76岁女性无牙颌患者,既往曾多次全口义齿修复,修复效果差。检查发现:下颌牙槽嵴极度低平,粘膜薄,上颌弓明显窄于下颌弓。旧义齿固位差,关系不稳定。

错误的排牙方法是()

A.前牙排成反

B.后牙采用交叉排牙法

C.后牙可减数减径

D.后牙可使用无尖牙

E.要有平衡关系

答案

参考答案:A

解析:

对于牙槽嵴低平,义齿的支持和固位条件差的患者,取印模时最好先制作个别托盘,以保证基托的密合和边缘伸展。排牙时,可通过减数或减径,使用无尖牙,获得平衡等方法,增强义齿的稳定,减小支持组织的负担。针对下颌弓宽于上颌弓的情况,可采用交叉排牙的方法将义齿的后牙排成反,但前牙通常不能排成反。

阅读理解

阅读理解。

     Many years ago, when I was working as a volunteer (志愿者) at a hospital, I got to know a little girl

 named Lisa. The poor little girl had a very serious disease and was dying. The doctor had done his best

 but no medicine really worked. The only chance to save her seemed to be a blood transfusion (输血)

 from her five-year-old brother. The little boy had the same disease before and had developed the

 antibodies (抗体) to fight the illness.

     The doctor talked to me little boy about what they planned to do, and asked him if he would be willing

 (愿意的) to give his blood to his sister. I saw him hesitate (迟疑) for a moment. He took a deep breath

 and said, "Yes, I'll do it if it can save Lisa."

     As the transfusion was going on, the little boy lay quietly in bed next to his sister. He 1ooked at her and

 smiled all the time. When everything was done and the colour returned to his sister's face, his smile

 disappeared and he looked a little afraid. He 1ooked up at the doctor and asked, "Will I start to die

 now?"

     He was too young to understand the doctor. He thought he would have to give all his blood to his

 sister, but he agreed.

1. What happened to the 1ittle girl named Lisa?

    A. She died of a very serious disease.

    B. he got better with the antibodies from her brother.

    C. She lost her little brother.

    D. The transfusion failed and her illness got worse.

2. The doctor waited the little boy to _____.

    A. give a11 his blood to his sister

    B. give some of his blood to his sister

    C. give his life to his sister

    D. get the same disease as his sister

3. How did the five-year-o1d boy understand the doctor's plan?

    A. He thought he was going to lose all his blood.

    B. He thought he was going to be killed.

    C. He thought he was going to die together with his sister.

    D. He thought he was going to die when he grew up.   

4. What did the boy feel when the doctor talked to him about the transfusion?

    A. He was unhappy to help his sister.

    B. He was so afraid that he refused to do anything.

    C. He was worried about his sister.

    D. He was willing to give his blood.

5. The writer still remember the story many years later _____.

    A. because the little girl had a very strange disease

    B. because the sister and brother had the same disease

    C. because the doctor saved the little girl's life

    D. because of what the boy did for his sister

判断题