Fianna Fáil have claimed that more than 1,000 children have been waiting for more than four years for orthodontic treatment.
The party's Health Spokesperson, Stephen Donnelly, has published the figures which were put together at the end of June, and he described them as "disgraceful".
The new figures show that 7,572 children are waiting more than two years for an appointment with 18,135 children in total on the waiting list.
By the middle of this year, there were 1,230 patients waiting more than four years.
Deputy Donnelly says this is a failure by Minister for Health Simon Harris and the HSE.
Mr Donnelly said: "The majority of them are waiting an unacceptably long time to be seen. More than 40% of children on the orthodontic list have been waiting for more than two years for an appointment.
"In fact, 1,230 have been waiting for over four years – an incredible situation.
“It’s just not good enough that a 14-year-old could be 18 before receiving, what in many cases is deemed “urgent”, treatment. Bear in mind that there is also another waiting list for assessment before they are even approved for treatment."