Calls are being made for changes to the system which allows dentists to perform orthodontic work.

An Auckland mother has criticised a dentist after her children needed thousands of dollars worth of corrective orthodontic treatment.

Five children needed corrective treatment after their procedures were carried out by a dentist, not an orthodontist.

New Zealand Association of Orthodontists president Dr Kieran O'Neill told Mike Hosking most dentists do not have the skills to perform specialist orthodontic work.

"They only do 80 hours over four years of training, and that's only one hour every two weeks. And that's simple observation, they're not actually hands on, treating patients."

He says people need to ask the tough questions.

"People rely on the dentist exactly what their qualifications are. Sometimes you have to ask 'are you a special orthodontist'."