www.newscientist.com/article/mg21428644-300-with-no-paper-trail-can-science-determine-age/
attempts to assess age with X-ray scans of teeth or wrists are doomed to failure, according to work to be published this week in the British Medical Bulletin. The fundamental flaw with such tests is that, because children grow at widely different rates, skeletal maturity shown on X-rays – which is used to gauge age – doesn’t necessarily match chronological age. Teenagers can have adult bone structure as early as 15 or later than 20, says study author Tim Cole at University College London (UCL). He says X-rays can provide the wrong answer about whether someone is under or over 18 up to a third of the time.
In wrist scans, age is estimated by looking at 20 or so bones initially separated by cartilage, but which progressively move closer to one another until they fuse in the mature wrist. The reference used for this test is a 1959 atlas compiled for doctors to assess healthy bone development, not age. It includes 1000 X-ray images of wrists of white middle-class American children, and the fully mature wrist of a 19-year-old. Yet wrists can be fully mature in children as young as 15, says Cole. A rival atlas compiled a few years later indicates a mean chronological age for wrist maturity of 17.6 years – give or take 1.3 years. So most “children” have “adult” wrists before 18.
I'm not saying age can't be figure out or that bone and teeth can't form part of that picture - I'm pointing out there's credible research showing there are issues with both bone and teeth x-rays and aging.
I'd agree with the articles conclusion
the best hope is in detailed assessments of physical and psychological development by specially trained paediatricians, skilled in combining different aspects of growth to make an informed estimate of age. It is crucial to chart a new way forward, he says: “Governments must stop believing that there is a ‘scientific’ test that will tell precisely the age of individuals claiming to be children but without papers to prove it.”