tetrade scar

例句：

1. 1. The patient had a tetrade scar on his forehead.
   病人额头上有一道四边形疤痕。
2. 2. The surgeon performed the surgery to remove the tetrade scar.
   外科医生进行了手术，以去除四边形疤痕。
3. 3. The tetrade scar was visible from a distance.
   从远处可以看到那道四边形疤痕。