There’s no sure-fire, scientific way of proving a person’s claimed age.
The search for a single, objective and reliable method has led to controversy over the use of dental x-rays.
Some local authorities, experts (and one ill-informed MP) have been pushing to use them, while the British Dental Association has deplored the practice as ‘inaccurate’ and ‘unethical’ given that the procedure are not medically required. Even the Home Office has expressed doubts.
Recently, Judges in the Court of Appeal have come to a different conclusion. They have ordered certain children refusing to undergo unnecessary dental x-rays to have them done or else have their claims struck out or stayed. Such orders were described by the Upper Tribunal (Immigration and Asylum Chamber) as ‘draconian’.
In R (on the application of ZM and SK) v The London Borough of Croydon (Dental age assessment)  UKUT 559 (IAC), Mr Ockleton, the Vice President of the Upper Tribunal , gave 7 points of guidance on the approach that Tribunals should take to the use of statistical data from dental x-rays and on when it is reasonable for a person to refuse to undergo the procedure.
1. Considerable circumspection must always be deployed in responding to a claim that statistical evidence tends to prove a fact about an individual. Statistics may be more useful to decision-makers at the far ends of the scale (where they may be able to show the plausibility or implausibility of a proposition) than in the middle of the scale where they purport to show the likelihood of the correctness of a plausible proposition.
2. When considering statistical evidence it is always necessary to determine whether the population constituting the database from which the statistics are drawn is sufficiently identical to the population from which the individual is drawn.
3. The fact that all teeth are mature in the sense that all have reached Demirjian stage H is a sign of chronological maturity but is not a reliable indicator of whether an individual is more or less than 18 years old. The use of the Demirjian stages below stage H does appear to be more reliable in the prediction of age, particularly in the lowerteens.
4. None of the three mandibular maturity markers so far identified appears yet to have attained such acceptance in the scientific community that it can be accepted as a reliable pointer to chronological age in the late teens in males.
5. Dental wear is not a guide to chronological age in the absence of data for a population with similar diet and masticatory habits to those of the person under examination.
6. The decision of the Court of Appeal in London Borough of Croydon v Y should not be read as prohibiting a person from refusing to undergo a dental examination. However, (i) the risk inherent in the exposure to x-rays during the taking of the dental panoramic tomograph is not likely to be a reasonable ground for refusing to allow the tomograph to be made, given the advantages stemming from ascertainment of an individual’s true age, and (ii) despite the reservations expressed herein, analysis of a person’s dental maturity may well have something to add to the process of assessing chronological age.
7. It therefore follows that generally speaking the taking of a dental tomograph should be ordered if a party seeks it, and (because of the process of dental maturity) the earlier the tomograph is taken, the more likely it is to be of assistance.
For more discussion on the law in this area, see my earlier post on dental x-rays and children from the Calais camp.