Permanent retainers also go by the following names:

• Bonded retainers
• Lingual wire
• Fixed retainers

Permanent retainers are more commonly used on the teeth of the lower jaw.

The retainer is called a lingual wire because it's glued or bonded to the back surface oof your teeth. It's easier to securely attach the bonding material to lower teeth such as the cuspids (canine teeth) for effective long-term use.

The name "permanent retainer" indicates exactly what the device does: stays on your teeth permanently to keep them from moving. You may have a permanent retainer on your teeth for the rest of your life.

Your dentist or orthodontist may remove your permanent retainer if it irritates your gums or teeth or causes too much plaque or tartar buildup on the teeth around it.

Read more at: https://www.healthline.com/health/permanent-retainer#about