According to Chris Kettler, executive secretary of the BOS, many orthodontists are being forced to abandon the NHS because government funding calculations failed to take into account the long-term nature of most treatments.
"A certain amount of orthodontists have been moving to doing their work privately and not taking NHS patients anymore - much as there has been among general dentists," Mr Kettler confirmed.
The spokesman explained that orthodontists are paid a fixed sum of money for a set volume of work.
"The government chose that sum of money by measuring what had been earned in a test period," he revealed.
However, Mr Kettler pointed out that many practices expanded during the two-year test period "but got very, very poor contracts".
"They were given funds to finish what [treatments] they'd started, but no more. So many, many practices have found themselves very short of funds," he explained.
According to the BOS, this shortage of funding has forced many practices to go private, limiting patient access to orthodontic treatment.