Methods:Dual X ray absorptiometry was used to measure the mineral density of alveolar bone after extraction of first or second molar in left mandible in the idividuals with different age in 22 males and 22 famales.

• 方法 :采用双能 X线吸收法测量不同年龄组的男性、女性拔牙后的牙槽骨骨密度。