An 11-year-old girl had three of her baby teeth removed without permission.

A crying 11-year-old girl was told to "smile" after an orthodontist had just removed three of her teeth without permission.

In a decision released on Monday, Deputy Health and Disability Commissioner Theo Baker found the orthodontist breached rights in the Health and Disability Code when he failed to inform the girl or her mother of the need to remove the teeth, and did so without consent.

The girl's mother told the commissioner they had visited the orthodontist for a consultation regarding future braces.

But the orthodontist ended up removing two of her daughter's baby teeth. When she asked what he was doing, he said: "I needed to get them out, because food could get stuck under them."

He then proceeded to remove a third tooth, as a dental assistant held the girl down.

The mother said the assistant "physically forced her down by the shoulder" and made insensitive comments such as, "Aww, it doesn't hurt".

After the teeth were removed, the orthodontist wanted to take photos, including one of the girl smiling, the mother said.

"[She] was still crying and in no mood to smile, the assistant yelled down the hallway, and I quote, 'Someone make this girl smile'."

Her daughter had been left "very traumatised" by the incident, which was unfortunate as she may need braces in the future, the mother said.

The orthodontist told the commissioner it was well known in dental practice that loose teeth could prevent a child from cleaning teeth properly and could prevent chewing due to discomfort and gum irritation.

He made a clinical decision that it was in the girl's best interest for the teeth to be removed, he said.

"Removing teeth from children is a sensitive matter for both children and parents. It is always my intention that an extraction be performed in a way that causes the least stress and discomfort to the child. In dental school I was taught to minimise any potential comments which may frighten or cause a child to refuse necessary treatment."

He said he considered he could remove them quickly and painlessly without anaesthetic.

"It is clear that I made a decision that was not mine to make. Without doubt, I should have discussed the required treatment more fully with [the girl's] mother prior to removing the baby teeth."

The orthodontist said he did not accept the girl was spoken to in an inappropriate way or that she was forcibly held on the chair.

"The assistant was gently guiding [the girl] to remain lying down while I quickly completed the final removal. The whole extraction took less than two minutes and I was anxious not to prolong matters."

While he could not recall the comments made while the photo was taken, he said he believed his assistant was simply trying to be "humorous" to distract the girl.

The deputy commissioner said the orthodontist had not informed the girl or her mother that the teeth required removal, nor did he inform them of the options available for removal, such as anaesthetic or referral to a general dentist. This was information a reasonable consumer in the circumstances would expect to receive, she said.

Furthermore, the removal was not documented in clinical records, which was another breach.

The deputy commissioner said there were "conflicting accounts" of the manner in which the girl was dealt with, so she was unable to determine whether dental staff had inappropriately held her down or made inappropriate comments.

She recommended the Dental Council of New Zealand review the orthodontist's competence, and the clinic provide an education seminar for its staff on informed consent.

The names of those involved and name and location of the clinic were withheld by the commissioner.