VOA慢速英语2011--Wising Up About Wisdom Teeth

Health Report - Wising Up About Wisdom Teeth

This is the VOA Special English Health Report.
Wisdom teeth are normally the last teeth to appear. This usually happens when people are in their late teen years or early twenties -- in other words, when they are older and wiser.
Wisdom teeth are molars, or chewing teeth, at the back of the mouth. The third set of molars, if you have them, are your wisdom teeth.
They can grow into place normally and never cause a problem. But often there is not enough room for them in the mouth. They might crowd other teeth. Sometimes they even push sideways through the gums.
An impacted wisdom tooth is one that fails to completely rise through the gums -- the term is erupt. Wisdom teeth that only partially¹ erupt can leave space for bacteria to enter around the tooth. Infection is a risk in these cases.
Wisdom teeth that are not well aligned² and become impacted are often removed.
People should have the placement of their wisdom teeth examined between the ages of sixteen and twenty. X-rays can show wisdom teeth that are below the gums.
The American Dental Association says removal is generally advised when wisdom teeth only partly break through the gums. Removal is also advised if there is a chance that poorly aligned wisdom teeth will damage other teeth. And removal is called for in cases where fluid collects around a wisdom tooth that is partly or fully³ below the gum.
But why do we have wisdom teeth if we often need to get them removed? One theory has to do with our diets. Scientists say the diet of prehistoric⁴ humans probably required more chewing teeth. Life was probably a little rougher on the teeth back then, too. So it was good to have extras.
The removal of wisdom teeth is performed by oral surgeons. They say if removal is advised, the best time to do it is before the teeth cause any problems or pain.
The American Association of Oral and Maxillofacial Surgeons says young adults are the best candidates for wisdom teeth removal. The group says older patients may be at greater risk for disease in the tissue surrounding the molars.
Patients can have general anesthesia during the operation. Or they might choose to have a local painkiller⁵ and remain awake. It may depend on the condition of the wisdom teeth and the number to be removed.
After surgery, there can be swelling⁶ of the gums and face and some pain. Both can be treated with cold wraps and medication.
And that’s the VOA Special English Health Report, written by Caty Weaver⁷. I’m Shirley Griffith.

1 partially   

adv.部分地，从某些方面讲

参考例句：

• The door was partially concealed by the drapes.门有一部分被门帘遮住了。
• The police managed to restore calm and the curfew was partially lifted.警方设法恢复了平静，宵禁部分解除。

2 aligned   

adj.对齐的，均衡的

参考例句：

• Make sure the shelf is aligned with the top of the cupboard.务必使搁架与橱柜顶端对齐。

3 fully   

adv.完全地，全部地，彻底地；充分地

参考例句：

• The doctor asked me to breathe in,then to breathe out fully.医生让我先吸气，然后全部呼出。
• They soon became fully integrated into the local community.他们很快就完全融入了当地人的圈子。

4 prehistoric   

adj.（有记载的）历史以前的，史前的，古老的

参考例句：

• They have found prehistoric remains.他们发现了史前遗迹。
• It was rather like an exhibition of prehistoric electronic equipment.这儿倒像是在展览古老的电子设备。

5 painkiller   

n.止痛药

参考例句：

• I shall persuade him to take the painkiller.我将说服他把药吃下去。
• The painkiller only provides him a short respite from his pain.止痛药仅仅让他在疼痛中有短暂的疏解。

6 swelling   

n.肿胀

参考例句：

• Use ice to reduce the swelling. 用冰敷消肿。
• There is a marked swelling of the lymph nodes. 淋巴结处有明显的肿块。

7 weaver   

n.织布工；编织者

参考例句：

• She was a fast weaver and the cloth was very good.她织布织得很快，而且布的质量很好。
• The eager weaver did not notice my confusion.热心的纺织工人没有注意到我的狼狈相。