Results The predilection age of cracked-teeth was 40 - 60 years old, the predilection teeth of cracked-teeth was maxillary molar and the first maxillary molar was the most freqnently found.

• 结果牙隐裂的好发年龄为40-60岁,好发牙位为上颌磨牙,其中以第一磨牙最为多见。