underhorn

例句：

1. 1. The underbite caused her to have trouble opening her mouth.
   下唇角导致她难以张开嘴。
2. 2.She was born with an underbite, which made her smile look unnatural.
   她出生时就有下唇角，这使得她的笑看起来不自然。
3. 3. The underbite can be corrected with orthodontic treatment.
   下唇角可以通过正畸治疗得到纠正。