What are the contraindications of those transparent braces?

Braces: The amount of root torque is one of the biggest challenges. If you need to flare the front teeth out or decrease the amount of flaring of the teeth then clear braces can make this challenging. If you put too much torque on the brackets the can break. Other contraindications may include how much you're involved in sports. Your orthodontist can explain more.

Dpnds on what u mean: There are a few types of transparent braces: invisalign (clear removable trays), ceramic (porcelain transparent braces), lingual (metal braces placed behind the teeth so they are not visible). Invisalign's primary contraindication is non-compliant patients. They must be worn 22h/day to be most effective. Clear ceramic/porcelain braces are primarily contraindicated on lower teeth bc of a deep bite.

There are very few: Clear aligner treatment is not for every orthodontic need. Only an individual assessment by an orthodontic specialist can determine if aligners are applicable to your situation.

Depends: Some here have answered in regards to invisalign. They are not braces, at all. Amongst the clear braces you ask about, they can be made of plastic or ceramics. The plastic ones flex too much and have inconsistent reactions to wire forces. The greek word for movement is "plastos" the root of plastic. Ceramic braces are more stiff, but are brittle, break, and can be hard to remove.

Many: Compliance is the major contraindication. They simply will not work if you do not wear them. Also manual dexterity and arthritis of your hand. You have to place and remove the aligners several times throughout the day. You can have someone assist you with this. High decay rates or periodontal disease. Only healthy teeth should be moved. Last is poor oral hygiene.