periodontal ligament

例句：

1. 1.The periodontal ligament is essential for maintaining the health of teeth and gums.
   牙周膜对于牙齿和牙龈的健康至关重要。
2. 2. During tooth eruption, the periodontal ligament helps to anchor the developing tooth in place.
   在牙齿萌出过程中，牙周膜帮助发育中的牙齿固定住。
3. 3. In some cases, periodontal ligament regeneration can be used as a treatment option for periodontitis.
   在某些情况下，牙周膜再生可以作为治疗牙周病的一种选择。