误区一:为了不害龋牙,必须常刷牙牙科医生建议一天刷牙的次数不要超过两次,刷牙次数过多,牙膏中含有的磨料可以洗刷珐琅,更易加重龋齿。误区二:大脑是头疼的罪魁祸首大脑是人体内唯一没有痛觉的地方,所以神经外科手术时可以不麻醉。但是头皮和头部非常敏感,有许多神经末梢。 Myth #1: To brush your teeth properly, you must always brush your teeth. The dentist recommends that you do not brush your teeth more than twice a day. Excessive brushing may cause the abrasive contained in the toothpaste to wash, making it easier to accentuate caries. Myth #2: The brain is the chief culprit for a headache The brain is the only place in the human body where there is no pain, so it can be done without neurosurgery. But the scalp and head are very sensitive and there are many nerve endings.