Why is orthodontics helpful, in terms of health? or is it just cosmetic?

Both: When teeth and jaws are well aligned they function better, aiding digestion, are easier to care for, prevent excessive wear, protect the jaw joints, enhance the health and stability of the supporting gums/bone, results in less expensive/extensive maintenance, and incidentally the smile then looks better. Go see a qualified Orthodontic Specialist for an exam and opinion.

Many reasons: a lorge percentage of orthodontic treatment is functional in nature. another percentage is to re-establish dental foundations for reconstruction. etc

Of course: Getting orthodontic treatment is more than just an aesthetic issue. Orthodontics has the ability to restore malocclusion to healthy function and to improve breathing and general health. See an orthodontist for consultation.

Ortho Tx for Health: Crooked or crowded teeth make it more difficult to clean/floss. Long term effects of not properly able to clean can lead to bone loss and periodontal disease. As for other issues, malocclusions can lead to difficult in chewing, and eating. Most orthodontic cases have a cosmetic compenent to them, but many drastically improve oral health too.

Straighter teeth are easier to clean but the process and the retainer wires can create problems of their own. I would say most orthodontics is for a cosmetic enhancement and could not be claimed to provide a health benefit. Some bite correction can reduce joint problems but others claim they have jaw problems from orthodontics.