Amber Athwal loved to dance. But she'll never dance again.

Now she lies in bed semi-conscious, curled up in pain.

The four-year-old was beyond excited, looking forward to the first day of kindergarten on Sept. 7.

Instead, she went to the dentist that day and has been in hospital ever since.

The little girl was was left brain damaged after she stopped breathing in the downtown Edmonton dentist's office for an undetermined amount of time.

Amber's uncle, Amanpreet Singh, shot a video of the little girl dancing at a housewarming party in early September.

"I often look at that video and it brings tears to my eyes," he said. "It's really sad. The family is devastated. Life will never be the same."

Routine dental checkup

It all began with a routine trip to the dentist on Sept. 2.

"She had front teeth decay and some molar cavities," Singh said. "So the doctor recommended her to a specialist because, according to him, this needed to be done under sedation."

Amber Athwal all dressed up for kindergarten orientation day and a trip to the dentist on Sept. 2 (Athwal family)

The dentist referred the family to Dr. William Mather and told them he is "one of the best in town," Singh said.

On Sept. 6, Mather's office called to say they had a last-minute cancellation for the next day and suggested bringing Amber in for an examination.

Around 8:15 a.m. on that Wednesday Amber ate a piece of bread with butter and a half cup of milk, according to her mother, Arsh Athwal. Then the girl's father drove her to Mather's office for the 9:30 a.m. appointment.

Singh said Mather told them he could do the surgery later that morning.

Amber's mother wrote in an online post: "He asked if my daughter Amber had anything to eat today and my husband told the specialist that she had breakfast. However, he said it's OK and carried on. He used general anesthetic for this procedure."

Singh said Amber's father held her hand while Mather put a mask over the little girl's face.

"She did resist a bit," Singh said. "While he was there, no intubation or heart monitoring or [blood pressure] rate check was done. We don't know what happened after that."

Once Amber was asleep, Mather sent her father to the reception area to wait before performing the surgery, Singh said.

'She stopped breathing'

About an hour later, the dentist approached Amber's father and asked him to come into the office lunchroom.

She wasn't breathing and paramedics were still doing CPR on her. - Amanpreet Singh

"He told him she stopped breathing after the procedure," Singh said.

The dentist appeared to downplay the severity of the situation.

"He told him he already called the paramedics, nothing to worry about, she'll be OK. They might need to take her to the hospital for a checkup.

"By the time my brother saw Amber," Singh said, "she wasn't breathing and paramedics were still doing CPR on her."

12 days in ICU

Singh said his niece was on a ventilator for a week and a half before she was able to breathe on her own. After 12 days, Amber was moved to a regular ward at the Stollery Children's Hospital.

A sign at Dr. William Mather's office identifies him as a dental surgeon and anesthesiologist. The Alberta Dental Association and College lists Mather as a general dentist. (Janice Johnston/CBC News ) A CBC News reporter visited the girl's hospital room and saw her lying in semi-fetal position on the hospital bed with her clenched, bandaged hand pressed up to the side of her face. She occasionally whimpered in pain. Sometimes her eyes opened but didn't appear to focus.

"They say she's going to be disabled for life," Singh said. "She's still tube-fed, and even though doctors say this might improve, she will still need a tube for the rest of her life because she might not be able to swallow that amount of food on her own. She'll be in diapers. She'll be wheelchair-bound."

Amber's parents have quit their jobs so they can stay with her around the clock while still taking care of Amber's two-and-a-half-year-old sister, who Singh said is upset and confused about what's happened to her big sister.

"She often asks why she's not waking up," Singh said. "She often cries when we take her to see Amber."

A GoFundMe page has been set up to help the family.

'What went wrong?'

Mather reported the incident to the Alberta Dental Association and College. It remains under investigation. Amber's family is frustrated with what they perceive as a lack of progress.

"We are not getting any answers," Singh said. "They don't give us a timeframe when we can get any answers. At least we want to know what happened. What went wrong? Looking at Amber, we need those answers now."

The registrar and CEO of the dental association refused to provide a timeframe to CBC News for presenting findings of its investigation.

Dr. William Mather, spotted through his office door, talking to a staff member. (Janice Johnston/CBC)

In an email, Dr. Randall Croutze said: "The Alberta Dental Association and College must balance a number factors when a reportable incident occurs — the safety of the public through appropriate standards and practices, requirement to protect patient privacy and conducting a thorough review in accordance with the Health Professions Act.

"While there may be information on this incident being shared by other parties, the ADA&C cannot provide further details on the incident as our extensive review is still underway."

Croutze had earlier confirmed the ADA&C has suspended Mather's licence to sedate patients pending the outcome of its investigation. Amber's family said they were told by the college that Mather is also temporarily not allowed to treat patients eight years and younger. The college and Mather refused to confirm that information.

The allegations made by Amber's family were put to Mather by email. A staff member in his office told CBC News Mather had read the email but added: "It's under investigation so he can't respond to it."

General anesthetic standards

The registrar and CEO of the College of Dental Surgeons of B.C. said incidents like what happened to Amber don't occur often.

"A tragic story like this is thankfully very rare, but always disturbing for the public, for dental professionals and for us as regulators," said Jerome Marburg.

Marburg said that in British Columbia, "all dental procedures" that involve general anesthesia require five qualified professionals: the anesthetist, the operating dentist, the operative assistant, the recovery supervisor and the office assistant.

In Alberta, a dentist is allowed to administer anesthetic at the same time as performing a surgical procedure.

Amber's family said they were not aware of anyone else in the room when Mather administered the general anesthetic. They're not sure who assisted the dentist during the surgery.

Ontario pediatric dentist Dr. Keith Morley is the past president of the American Academy of Pediatric Dentistry. He told CBC News the standard rule is no eating or drinking after midnight for a patient who is going to receive a general anesthetic.

Morley also said it's standard operating procedure for a patient to be hooked up to a heart monitor and fitted with a blood-pressure cuff before the anesthetic is administered.

Morley said a patient's temperature is also closely monitored along with oxygen and carbon dioxide levels.

Said Marburg: "We do not know the circumstances or what went wrong, but want to assure the public that general anesthetic procedures in dentistry are very safe."

Amber's uncle doesn't want this to happen to anyone else.

"Select your doctor carefully," Singh said. "I don't know whose fault it is. Still, please be aware of what procedure you're going through. Just do a little bit of investigation beforehand."