More than 10,000 children with severe dental problems are waiting up to seven years for corrective treatment on the NHS.
Orthodontists have warned that in many cases the children suffer from much more serious problems by the time they are finally given treatment.
These can include jaw deformities and an inability to bite properly.
They also warned that the government’s introduction of an 18-week waiting time target for orthodontics at the end of the year would be so difficult to meet that patients would not be referred at all and treatment would be rationed further.
Evidence of the collapse in orthodontics in parts of the country is revealed in research by the British Orthodontic Society (BOS).
It found that in at least seven hospital catchment areas in England, children with serious conditions were waiting more than four years for hospital treatment.
In one area of the north east children are waiting for seven years while in another the delay is five and a half years.
Orthodontists report that some children turn 18 while waiting to be assessed for care and lose their chance of surgery on the NHS.
A Department of Health spokeswoman said: ‘The department is aware of the variations in provision of orthodontic treatment and has given help to primary care trusts in assessing and reviewing future orthodontic services.’