'Teen Mom' Mackenzie Edwards Claims Ex Ryan Edwards Relapsed, Gets Temporary Custody

Former "Teen Mom" star Mackenzie Edwards has been granted temporary custody of her two kids, whom she shares with ex-husband Ryan Edwards ... and a judge ruled that he can only see them at his parents' house after she claimed he relapsed on drugs.

In a court order, the Tennessee judge restricted Ryan's contact with their kids and barred him from driving and transporting them ... Us Weekly reports.

Meanwhile, Ryan's wife, Amanda Conner, has also been prohibited from supervising them, driving them, or being alone with them.

As part of the order ... Ryan -- who has had multiple past arrests -- will have to have his fingernails tested for drug use.

Mackenzie had claimed in an emergency petition that Ryan had allegedly used the herbal substance Kratom -- which is banned in Tennessee.

Her legal team says that the custody change is all to ensure the children's safety ... and that she wants them to maintain a relationship with Ryan's parents.