日批在线视频_内射毛片内射国产夫妻_亚洲三级小视频_在线观看亚洲大片短视频_女性向h片资源在线观看_亚洲最大网

   

WORLD / Asia-Pacific

9,000-year-old dental drill is found
(AP)
Updated: 2006-04-06 08:17

Proving prehistoric man's ingenuity and ability to withstand and inflict excruciating pain, researchers have found that dental drilling dates back 9,000 years.

Primitive dentists drilled nearly perfect holes into live but undoubtedly unhappy patients between 5500 B.C. and 7000 B.C., an article in Thursday's journal Nature reports. Researchers carbon-dated at least nine skulls with 11 drill holes found in a Pakistan graveyard.

An undated illustration of Neolithic weapons found in England. In the absence of modern metal tools the Neolithic drill of choice 9,000 years ago was a flint head, according to Roberto Macchiarelli, of the University of Poitiers in France. While excavating in Pakistan, Macchiarelli and a team of scientists found drilled molars from nine adults discovered in a grave that date from 7,500 to 9,000 years ago.
An undated illustration of Neolithic weapons found in England. In the absence of modern metal tools the Neolithic drill of choice 9,000 years ago was a flint head, according to Roberto Macchiarelli, of the University of Poitiers in France. While excavating in Pakistan, Macchiarelli and a team of scientists found drilled molars from nine adults discovered in a grave that date from 7,500 to 9,000 years ago. [Reuters]

That means dentistry is at least 4,000 years older than first thought — and far older than the useful invention of anesthesia.

This was no mere tooth tinkering. The drilled teeth found in the graveyard were hard-to-reach molars. And in at least one instance, the ancient dentist managed to drill a hole in the inside back end of a tooth, boring out toward the front of the mouth.

The holes went as deep as one-seventh of an inch (3.5 millimeters).

"The holes were so perfect, so nice," said study co-author David Frayer, an anthropology professor at the University of Kansas. "I showed the pictures to my dentist and he thought they were amazing holes."

How it was done is painful just to think about. Researchers figured that a small bow was used to drive the flint drill tips into patients' teeth. Flint drill heads were found on site. So study lead author Roberto Macchiarelli, an anthropology professor at the University of Poitiers, France, and colleagues simulated the technique and drilled through human (but no longer attached) teeth in less than a minute.

"Definitely it had to be painful for the patient," Macchiarelli said.

Researchers were impressed by how advanced the society was in Pakistan's Baluchistan province. The drilling occurred on ordinary men and women.

The dentistry, probably evolved from intricate ornamental bead drilling that was also done by the society there, went on for about 1,500 years until about 5500 B.C., Macchiarelli said. After that, there were no signs of drilling.

Macchiarelli and Frayer said the drilling was likely done to reduce the pain of cavities.

Macchiarelli pointed to one unfortunate patient who had a tooth drilled twice. Another patient had three teeth drilled. Four drilled teeth showed signs of cavities. No sign of fillings were found, but there could have been an asphalt-like substance inside, he said.

Dr. Richard Glenner, a Chicago dentist and author of dental history books, wouldn't bite on the idea that this was good dentistry. The drilling could have been decorative or to release "evil spirits" more than fighting tooth decay, he said, adding, "Why did they do it? No one will ever know."

Macchiarelli said the hard-to-see locations of the drilled teeth in jaws seem to rule out drilling for decorative purposes. Frayer said the prehistoric drillers' skill is something modern-day patients can use to lord over their dentists.

"This may be something to tell your dentist: If these people 9,000 years ago could make a hole this perfect in less than a minute," Frayer said, "what are they doing?"

 
 

主站蜘蛛池模板: 成人做爰69片免费观看 | 欧美国产精品一二三 | 日日摸日日干 | 日本中文在线 | 国产精品高清在线 | 日本黄色免费网站 | 久草视频手机在线 | 精品一区在线播放 | 在线国产福利 | 2020亚洲天堂 | 超碰精品在线观看 | 99久久久久久久久 | 国产日韩在线视频 | 午夜影院h| 国产不卡一区 | 超碰97在线免费 | 国产99久久久国产精品免费看 | 久色免费视频 | 亚洲欧洲一区二区 | 欧美三级欧美成人高清 | 欧美日韩精品一区二区三区四区 | 亚洲丁香网 | 久久一线 | 国产黄色在线 | 国产美女在线播放 | 中文字幕在线播放一区 | 起碰在线视频 | 天堂8在线视频 | 国产黄色免费网站 | 免费欧美一级片 | 欧美日韩免费做爰视频 | 国产激情在线播放 | 天天夜夜爽 | 99久久久久成人国产免费 | 国产视频久 | 在线观看视频国产 | 夜夜骚av| 九九资源站 | 欧美综合第一页 | 亚洲成人www | 99久久这里只有精品 |