Estimation of age using dental radiographs

In lieu of recent criticism from the Atomic Energy Regulatory Board (AERB), India regarding the exposure of radiographs for dental age estimation, Date of Birth Foundation had published a review article titled “Estimation of age using dental radiographs is a justifiable procedure” written by a team of comprising of Dentists, Radiologists, and Forensic Specialists from the UK, USA, Australia and Hong Kong.

D.O.B Foundation had seeked further clarification from AERB regarding their press statement. ‪#‎dobfoundation


“Estimation of age using dental radiographs is a justifiable procedure”

Jayakumar Jayaraman1, Graham J. Roberts2, Mel Mupparapu3, Nigel M. King4, Phil H. Marsden5, Fraser McDonald6, Victoria S. Lucas7, Steven R. Singer8, Hai Ming Wong9


1 Founder & Director, Date of Birth Foundation, 73, 11/F Sze Yap Building, 73 Des Vouex Road West, Hong Kong

2 Honorary Professor, Paediatric Dentistry, King’s College London Dental Institute, Floor 22, Tower Wing, Guy’s Hospital, London, SE1 9RT, United Kingdom

3 Professor, Division of Oral & Maxillofacial Radiology, University of Pennsylvania School of Dental Medicine, Philadelphia, PA 19104, United States

4 Professor, Paediatric Dentistry, University of Western Australia, Crawley WA 6009, Perth, Australia

5 Forensic Odontologist, 170 Holland Park Avenue, London, W11 4UH, United Kingdom

6 Professor, Orthodontics, King’s College London Dental Institute, Floor 22, Tower Wing, Guy’s Hospital, London, SE1 9RT, United Kingdom

7 Specialist in Paediatric Dentistry, King’s College London Dental Institute, Floor 22, Tower Wing, Guy’s Hospital, London, SE1 9RT, United Kingdom

8 Professor & Acting Director, Division of Oral & Maxillofacial Radiology, Rutgers School of Dental Medicine, Newark, NJ 07101, United States

9 Associate Professor, Paediatric Dentistry & Orthodontics, University of Hong Kong, 34 Hospital Road, Hong Kong


Estimation of age using dental radiographs is a justifiable procedure

Abstract  :

Age assessment is conducted following suspicions of false age claims mainly due to lack of authentic birth documents resulting from inadequate birth registration practices. The need for age assessment has intensified in recent years due to the increase in the number of cross-border migrations and criminal activities by juveniles. Dental maturity closely correlates with chronological age and this method has been proven to estimate age with reasonable accuracy. Radiographs serve as an excellent tool that allows visualization of calcified structures and hence assessment of age using radiographs is common practice. Recently, criticisms were raised against the use the radiographs for dental age estimation which has sparked widespread debate. The opponents claim that radiation exposure can be justified only based on clinical benefits. This report analyses the existing guidelines on radiation exposure to justify, on scientific and logical grounds, that radiographs can be used for dental age assessments.



Dental Radiographs, Dental Age Assessment, Chronological Age, Legal Justification


The need for age estimation stems from both inadequate registration of births and an increase in illegal immigration. This process needs to be conducted on those individuals who have no identification documents or where it is suspected that their birth date has been falsified. The relationship between physical growth, maturation, and birth date or chronological age is an established phenomenon [1]. Panoramic dental radiographs provide a large archive of developing teeth in otherwise healthy children, adolescents, and emerging adults; thus providing a unique collection of baseline data for a database that contains accurate gender, ethnic and age data for specific Reference Data Sets [2]. Furthermore, dental radiographs exhibit a very close correlation between estimated dental age and chronological age. This has been shown, for the United Kingdom (UK), in validated studies at the 10-year threshold, which is the age of criminal responsibility [3], the 13-year threshold that is the age below which sexual intercourse is deemed to be statutory rape [4], and the 16-year threshold that is the age of consent for sexual activity [5]. Research work is currently in progress to explore the application of the Reference Data Set to the 18-year threshold, because this is the defining age between childhood and adulthood in India and many other countries across the world. Despite this compelling evidence, the use of radiographs for assessing age has attracted criticism [6, 32, 33]. Therefore, this review aims to evaluate the risks and benefits of dental radiographs for age assessment and to consider the legality of using radiographs for non-medical purposes.


Birth registration and asylum claims

Approximately 45% of children in the world are not registered at birth. This is most prevalent in the continents of Asia and sub-Saharan Africa, which contribute 60% of the total of unregistered births [7]. Without birth registration, these children are unable to enroll in a school, obtain a driving license or passport. Furthermore, access to social security benefits is denied. Despite the efforts to improve birth registration, for example, in India, 10 million births still go unregistered every year [8].

According to UNHCR, the total numbers of refugees at the end of 2011 was estimated to be 10.55 million, of which an estimated 4.3 million people were newly displaced to another region due to conflict or persecution. The number of asylum applications received in the 44 industrialized countries was 479,300 in the year 2012, an 8% increase compared to 2011. The majority of the asylum claims are from Asia (46%) followed by Sub-Saharan Africa (25%) [9]. An underlying factor is the rise in civil wars and associated conflicts that lead to humanitarian distress. The number of asylum claims in Australia dramatically increased by 37% between 2011 and 2012 [10].

Problems of birth date disputes

The presence of large numbers of asylum seekers in advanced economies imposes considerable additional costs in social benefits payments for the host country. To add to this expense, age disputes have resulted in higher spending by the host governments. Recently, over one million British pounds sterling was paid out as compensation by the United Kingdom (UK) Home Office for detaining forty children who were wrongly considered by them to be adults [11].

In 2010, the UK Border Agency refused 88% of asylum claims by subjects whom they deemed to be over 18 years of age. In contrast, only 12% of claims by subjects under the claimed age of 17 years were refused. When wrongly identified as an adult, children have been placed in adult detention camps and as a consequence have suffered emotional disturbances [12]. When there is a delay in the age assessment process, an appropriate guardian is not always appointed in good time so the affected children are often placed with adults until the assessment process has been completed. International law identifies the attainment of majority at 18 years of age. This age, in legal terms, demarcates a child from an adult. However, the legal system differs among countries and subjects are dealt with based on legislation within the local legal system. When confronted by immigration or legal authorities, subjects at this age threshold have their age disputed when they are unable to provide authentic proof of their date of birth. Sometimes, an individual intentionally falsify their age in order to enjoy the legal benefits of childhood; that includes foster care, shelter, and education. In those circumstances, when an individuals’ age is under dispute they may be referred to a social mediator, a medical or dental practitioner to estimate their chronological age by evaluating developmental or skeletal or dental development.

Global trends in age assessment practices

Although each country has its own legal framework including policies and practices for dealing with asylum claims and age assessments, skeletal and dental age assessment methods are currently used in most countries. A review conducted by Separated Children in Europe Program (SCEP) concluded that there has been no universal consensus adopted for age assessment across Europe. Furthermore, in most countries, there are no specific laws to govern the practice of age assessments and the role for individuals involved in this procedure. A combination of skeletal and dental age assessments is practiced in Austria, Belgium, Denmark, Finland, France, Norway and United Kingdom. Skeletal age assessment is seldom conducted in Hungary and dental age assessments are not practiced in the Netherlands [13]; whilst, in the United States, dental age assessments are more frequently used than skeletal assessments [14]. Recently, Australian Human Rights Commission directed to withdraw the method of skeletal age estimation from hand-wrist radiographs following an enquiry as a means to deal with age assessment procedures on illegal immigrants from Indonesia [15]. It is evident from the available literature that there is a lack of an accepted systematic approach for handling age disputes and asylum claims in most of the industrialized nations in the world.

Accuracy of age estimation methods

Evaluating developmental indicators including physiological, skeletal, dental and psychological maturity can assess age. Physiological maturity indicators include height and weight assessments and the appearance of secondary sexual characteristics. These methods can provide estimate of an individual’s age based on a mean scale of maturity but they cannot accurately estimate the individual’s age. Dental maturity correlates closely with the gold standard of chronological age [16]. Although physical and sexual maturity can be assessed by visual examination, dental maturity needs to be evaluated through radiological examination of the whole dentition.

According to the recommendations issued by the Study Group on Forensic Age Diagnostics [17], for determining the age of live subjects, a forensic age estimate should combine the results of a physical examination, and of a radiograph of the hand and wrist. In addition, a dental examination is also performed which records the state of development of the dentition based on a panoramic radiograph [17]. To date, there is no evidence to prove that the age assessed by the combination of these is any more provide accurate than a method such as dental age assessment used alone. It has been demonstrated that dental age is more accurate indicator of chronological age than the any other method. One major reason is that it is less influenced by environmental and nutritional changes [2-5].

The most vital part of an age assessment method is the quality and accuracy of the reference data that are used for estimating the age for an individual. For dental age assessments, reference data have been obtained from dental maturity scores of French-Canadian children that were collated in the 1960s [18]. A recent review in 2013 has found that these data overestimate the age of children and hence are unreliable for age assessments [19]. Evolutionary changes accompanied by nutritional and environmental modifications have resulted in secular changes in physical maturity. These trends include advancements in the ages of attaining puberty, and changes in height and weight [20]. Hence, gender, ethnic, and secular changes must be taken into consideration during the application of reference data for age assessment [21].

The accuracy of an estimated age depends on the number of parameters that are available for analysis. For example, when making an age assessment using the dentition, the accuracy decreases as teeth reach maturity as a child passes through adolescence to an emerging adult. A large UK Caucasian Reference Data Set based on the maturity of the teeth has been accumulated at King’s College London. This database, which is the largest in existence, includes over 16,000 cases, comprising Afro-Trinidadian, southern Chinese, Israeli, and Maltese; and has been validated at different age thresholds [2-5]. To date, this is the only method that is able to estimate the age of subjects with reasonable accuracy. Although scientific evidence has shown that age assessed through dental maturity is accurate [4,5], there are frequently claims against the accuracy of this method. A recent development has been the use of probability estimates at specific age thresholds. These show that assignment to above or below a specific threshold is more than 90% accurate for European Caucasians at the 10-year threshold (31).

Radiographs in clinical medicine and dentistry

Regulations exist for the use of radiographs to ensure that all ionizing radiation for any purpose are justified. The annual frequency of diagnostic dental examinations in level II countries, which are identified by the presence of one physician for every 1000 to 2999 people, has risen from 0.16% in 1984 to 16% in 2007 [22]. In recent years, there has been a dramatic increase in the use of pan-oral radiographs in general dental practice, especially in the Heavily Indebted Poor Countries (HIPC). However, advancements in radiological exposure techniques including use of high-speed film, collimation, film positioning and digital detectors like CCD/CMOS/PSP plates have been introduced to minimize radiation exposure [23]. Although guidelines have been set to impose minimal radiation exposure to the patients, the issues relating to faulty radiographic techniques, over-use of radiographs for non-specified purposes, still occur in many dental practices [24]. The dental regulatory bodies appear not to strongly oppose these minor, but commonly prevailing practices, possibly because of the reduction in radiation received by patients undergoing potentially diagnostic radiographic examinations.

The use of radiographic exposure is an integral part of the process of dental age assessment. The regulatory and legal aspects of the use of radiographs have been brought together and articulated in a single document [25]. As a dentist making the decision to expose an individual to radiation for age assessment reasons, potentially has net benefits for the individual and society. If the resulting conclusion is that they are the age that they have stated they will receive the most appropriate level of support; conversely if the conclusion is that, on the balance of probabilities, the individual is older than claimed, and above a certain age threshold. The limited resources were used wisely and were legitimately needed and were therefore of benefit to society. Experience has shown that the most common outcome is that the individual is older than claimed. This means that whatever the outcome, there is potentially a net benefit to all parties concerned. In addition, the radiographic assessment of age disputed asylum seekers is standard practice in very many countries and could not be seen as unusual practice bearing in mind the lack of other suitable ageing markers that are available to assess age. The taking of radiographs where there is no therapeutic benefit to the individual is allowed under existing legislation.

Age assessment using radiographs

Age assessments are usually conducted by making an evaluation of skeletal and dental maturity using a radiograph. In the UK legislation exists, for example, Ionizing Radiation Medical Exposure Regulation (IRMER) which recommends controlled radiation exposure by ensuring justification for such exposures, use of optimization methods and dose limitation protocols [24]. Although the use of radiographs for dental age assessments has been legally permitted, this has not been agreed by all organizations. Within the UK, British Association for Forensic Odontology (BAFO) and British Society of Dental Maxillo-Facial Radiology (BSDFMR) supports the taking of radiographs for age assessment. However, this practice has been strongly criticized by the Royal College of Paediatrics, Child Health (RCPH) and the Immigration and Law Practitioners’ Association (ILPA) and Royal College of Radiologists (RCR). More recently, a strong opposition came from the Atomic Energy Review Board in India following a project in which age certificate were issued to children and orphans in Mumbai through dental age estimation [33].

Is this procedure justified?

Many countries have experienced a rapid increase in the demand for forensic age estimates of unaccompanied minors and age assessment has now become an integral part of forensic practice. Identification of the exact date of birth is virtually not possible and no method has ever able to achieve this. It is also evident that the most accurate age assessments are only possible from radiographs. A need for a holistic method of age assessment has been debated in recent years [31]. However, there is no published evidence that any attempt has been made to validate this method. Contradictory views still exist on the reliability of age assessment methods; nevertheless there is evidence suggesting that modern dental age assessment methods are accurate to within three months of the true age [2-5]. Furthermore, estimates of the probability of a subject being above a specific age threshold show that there is a 90% or greater probability of a correct assignment below or above a specific threshold (31). Whilst, the so-called, holistic assessment, may well be appropriate for determining a child’s social, educational and care needs does not translate into a reliable estimate of chronological age. Without validation it is misleading to suggest that it is suitable method of estimating age, especially when the individual is at a critical age threshold and the consequences are critical.

Age assessment has to be conducted as a measure of last resort when all other efforts to gather evidence of an individual’s age have failed. The assessment has to be conducted in conjunction with behavioral, cognitive, and psychological evaluation of a child’s knowledge plus an understanding of her/his life circumstances [30]. The risk of exposure to very low levels of ionizing radiation has to be balanced against the potentially benefits to the individual. The authors strongly recommend that a universal consensus has to be reached on age assessment practices and related problems such as radiation exposure, psychometric analysis, methods of obtaining consent, providing legal benefits and whilst being cognizant of the care of the subjects involved in the process.

An often under considered issue is that age assessment could provide an approximation to the truth. Perhaps such a concept is alien to those who seek to deny children, adolescents and emerging children the right to have a reliable age estimate. This procedure would become a resource intensive problem, as there is a continued and sustained increase in the number of children seeking asylum. Due to poor birth registration practices, most of them do not have formal record of their birth. Immigrants seeking asylum travel by different means including catamarans, and boats that exposes them to long days of sunlight and background radiation. Should we prohibit them seeking appropriate care by just not taking a radiograph which carries an insignificant risk of harm? This is a less than 1 in 2 million lifetime risk of them developing cancer [29].


It is our view that a simple panoramic radiograph, with a minute ionizing radiation dose, provides an enormous amount of relevant and accurate information about an individual’s developmental status; and to deny either the individual, or the state the benefit of this detailed and accurate knowledge is synonymous with institutional neglect. The use of radiographs will help many children who are wrongly accused of being an adult, and protect children from being housed with adults mis-identified as children. Perhaps the most important outcome will be a recognition that the truth of age will emerge. Healthcare providers have ‘protection of the patient’ as a foundation of their profession. Failing to protect children from exposure to share housing with adults and to impose legal adult penalties on them has to bring into question the arguments to ignore to the value of age assessment.


Footnotes Acknowledgement:

The authors would like to acknowledge Dr Eric Whaites, King’s College London Dental Institute for his advice and guidance during the preparation of this paper.

Contributors: All authors contributed to the conception of this paper. JJ designed the structure of paper and produced the first draft. GJR, NMK and MM coordinated the revision of subsequent drafts. PHM provided guidance on the taking of radiographs for dental age assessments. HMW, FMcD, GJR and VSL contributed to some sections, and critically reviewed the paper. All authors approved the final version of the manuscript.

Competing interests: All authors declare no financial support.

Reference to article : DOB Foundation

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