David Davies, chairman of the Commons Welsh Affairs select committee, has said that mandatory dental checks should be made to verify the age of child migrants - and dentists aren't happy about it.
The British Dental Association (BDA) said demands by Davies for testing on those heading to Britain from the Jungle refugee camp was "inappropriate and unethical".
Davies argues that these checks would reassure the public the system was not being exploited.
After the arrival of 14 teenagers to the UK from Calais on Monday, Davies said they "don't look like children".
"I hope British hospitality is not being abused", he added.
The BDA has disputed claims that dental radiographs can accurately say if someone has reached 18 years of age.
A spokesman said: "We are vigorously opposed to the use of dental X-rays to determine whether asylum seekers have reached 18.
"It's not only an inaccurate method for assessing age, but it is both inappropriate and unethical to take radiographs of people when there is no health benefit for them."
The Jungle refugee camp could be closed imminently after a French court rejected an appeal from aid groups to delay the clearance.