The researchers then inquired about both groups' family, medical and dental histories.

研究人员获取了这两组研究对象的家庭，病史和牙科史（数据）。

In the case of their dental histories, participants were asked whether they generally had standard X-rays, known as bitewings, every year, or never had them, or fell somewhere in between.

对于他们的牙科史，参与者被问及他们是否通常每年接受被之称之为咬翼片的常规牙医X光，或是从没拍过，或是介于以上两者之间。