The function of the periodontal ligament is what?

Shock absorbers: Teeth are not really held in bone or attached to bone. They are held in place by periodontal ligaments. So really the tooth is suspended inside a bony socket. As tartar builds up or gums and bone receed....The periodontal ligaments disappear too. Earl.

Has several : There are several purposes. The primary purpose is to attach the teeth to the bone in a manner that enables them to move - absorb some pressure/force without breaking. They also enable teeth to move - with braces. They also contain stem cells that can be recruited to enable bone/tooth to be repaired/rebuilt.