But wisdom teeth weren't always a cash crop for oral surgeons. Long ago, they served as a useful third set of meat-mashing molars.
很久以前，智齿是作为把肉嚼碎的第三磨牙而派大用处的，不是像现在只是留给口腔医生去拔掉。
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As evolution made its selections, our diets changed, our jaws grew appropriately smaller, and our thirdmolars became unnecessary.
由于进化中的不断选择，我们的饮食发生了变化，我们的下巴也相应变小，而第三臼齿也就没用了。
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Methods: 524 cases of impacted mandibular thirdmolars were extracted with air turbine handpiece or chisel, in which 131 cases happened complications during operation or post-operation.