Age estimation in three distinct east Asian population groups using southern Han Chinese dental reference dataset.

BACKGROUND: Dental age estimation can assist in the identification of victims following natural disasters and it can also help to solve birth date disputes in individuals involved in criminal activities. A reference dataset (RDS) has been developed from the dental development of 2306 subjects of southern Han Chinese origin and subsequently validated. This study aimed to test the applicability of the southern Han Chinese dental maturation RDS on three distinct East Asian population groups. METHODS: A total of 953 dental panoramic radiographs of subjects aged 2 to 24 years were obtained from Philippines, Thailand and Japan. The staging of dental development was conducted according to Anglo-Canadian classification system. The dental age (DA) was calculated using six methods; one un-weighted average and five weighted average (n-tds, sd-tds, se-tds, 1/sd-tds, 1/se-tds) methods based on the scores of the southern Han Chinese RDS. Statistical significance was set at p < 0.05 and the variation between chronological age (CA) and DA was evaluated using paired t-test and Bland & Altman scatter plots. RESULTS: From six dental age calculations, all methods of DA accurately estimated the age of Japanese and few methods in Filipino subjects (n-tds, 1/sd-tds, 1/se-tds). There was consistent overestimation of age for all the methods for Thai females (p < 0.05). CONCLUSIONS: The southern Han Chinese dental reference dataset was shown to be most accurate for Japanese, followed by Thai males and it was particularly ineffective for Filipinos and Thai females.

Dental age estimation in southern Chinese population using panoramic radiographs: validation of three population specific reference datasets.

BACKGROUND: The accuracy of estimated age should depend on the reference data sets (RDS) from which the maturity scores or Ages of Attainment (AoA) were obtained. This study aimed to test the accuracy of age estimation from three different population specific dental reference datasets (RDS). METHODS: Two hundred and sixty six dental panoramic radiographs of subjects belonging to southern Chinese ethnicity were scored and dental age (DA) was estimated from three reference datasets: French-Canadian, United Kingdom (UK) Caucasian and southern Chinese. Statistical significance was set at p < 0.05 and for each method, the difference between the chronological age (CA) and dental age (CA-DA) was calculated using paired t-tests. In addition, Chi-square tests were performed to evaluate the accuracy of the age estimates within specific time interval from CA. RESULTS: The estimated age difference (CA-DA) using the French Canadian RDS was - 0.62 years for males and - 0.36 years for females. For the UK Caucasian RDS, the age difference was 0.25 years for males and 0.23 years for females. The difference observed using the southern Chinese RDS was - 0.02 years for both genders and the difference was not statistically significant (p > 0.05). The southern Chinese RDS estimated the age of 80% of subjects within ±12 months range, and 90% of subjects within ±18 months range (p < 0.05) showing it to be more accurate than other datasets. CONCLUSION: It is concluded that population specific Reference Data Sets improve the accuracy of dental age estimation.

Antibiotics for the prophylaxis of bacterial endocarditis in dentistry.

BACKGROUND: Infective endocarditis is a severe infection arising in the lining of the chambers of the heart with a high mortality rate.Many dental procedures cause bacteraemia and it was believed that this may lead to bacterial endocarditis (BE) in a few people. Guidelines in many countries have recommended that prior to invasive dental procedures antibiotics are administered to people at high risk of endocarditis. However, recent guidance by the National Institute for Health and Care Excellence (NICE) in England and Wales has recommended that antibiotics are not required. OBJECTIVES: To determine whether prophylactic antibiotic administration, compared to no such administration or placebo, before invasive dental procedures in people at risk or at high risk of bacterial endocarditis influences mortality, serious illness or the incidence of endocarditis. SEARCH METHODS: The following electronic databases were searched: the Cochrane Oral Health Group's Trials Register (to 21 January 2013), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2012, Issue 12), MEDLINE via OVID (1946 to 21 January 2013) and EMBASE via OVID (1980 to 21 January 2013). We searched for ongoing trials in the US National Institutes of Health Trials Register (http://clinicaltrials.gov) and the metaRegister of Controlled Trials (http://www.controlled-trials.com/mrct/). No restrictions were placed on the language or date of publication when searching the electronic databases. SELECTION CRITERIA: Due to the low incidence of BE it was anticipated that few if any trials would be located. For this reason, cohort and case-control studies were included where suitably matched control or comparison groups had been studied. The intervention was the administration of antibiotic, compared to no such administration, before a dental procedure in people with an increased risk of BE. Cohort studies would need to follow those individuals at increased risk and assess outcomes following any invasive dental procedures, grouping by whether prophylaxis was received or not. Included case-control studies would need to match people who had developed endocarditis (and who were known to be at increased risk before undergoing an invasive dental procedure preceding the onset of endocarditis) with those at similar risk but who had not developed endocarditis. Outcomes of interest were mortality or serious adverse events requiring hospital admission; development of endocarditis following any dental procedure in a defined time period; development of endocarditis due to other non-dental causes; any recorded adverse events to the antibiotics; and cost implications of the antibiotic provision for the care of those patients who developed endocarditis. DATA COLLECTION AND ANALYSIS: Two review authors independently selected studies for inclusion then assessed risk of bias and extracted data from the included study. MAIN RESULTS: No randomised controlled trials (RCTs), controlled clinical trials (CCTs) or cohort studies were included. One case-control study met the inclusion criteria. It collected all the cases of endocarditis in the Netherlands over two years, finding a total of 24 people who developed endocarditis within 180 days of an invasive dental procedure, definitely requiring prophylaxis according to current guidelines, and who were at increased risk of endocarditis due to a pre-existing cardiac problem. This study included participants who died because of the endocarditis (using proxies). Controls attended local cardiology outpatient clinics for similar cardiac problems, had undergone an invasive dental procedure within the past 180 days, and were matched by age with the cases. No significant effect of penicillin prophylaxis on the incidence of endocarditis could be seen. No data were found on other outcomes. AUTHORS' CONCLUSIONS: There remains no evidence about whether antibiotic prophylaxis is effective or ineffective against bacterial endocarditis in people at risk who are about to undergo an invasive dental procedure. It is not clear whether the potential harms and costs of antibiotic administration outweigh any beneficial effect. Ethically, practitioners need to discuss the potential benefits and harms of antibiotic prophylaxis with their patients before a decision is made about administration.

Dental age assessment (DAA): reference data for British children at the 10-year-old threshold.

The purpose of this work was to develop a reference dataset for dental age assessment at the 10-year-old threshold. Dental panoramic radiographs of children aged between 9 and 11 years were reused to determine the age of attainment of tooth development stages relevant to the 10-year threshold. These data were used to test the accuracy of the dental age assessment (DAA) on a separate study sample of known chronological age. The study sample comprised 100 radiographs (50 female, 50 male) of known chronological age that did not form part of the reference dataset. For each subject in the study sample, the mathematical procedure used in meta-analysis was applied to all teeth that were still developing. The weighted average of all the developing teeth in a given child was assigned as the dental age for that individual. This was compared to the gold standard of chronological age. Three thousand six hundred sixty-two radiographs comprised the reference sample. The mean difference between the chronological age and dental age estimated for the sample of female subjects was 0.12 years (1.44 months) and for the males was 0.33 years (3.96 months). A method comparison technique was used to evaluate the difference between the chronological age and estimated dental age for each study subject. This showed a good agreement for both females and males. DAA using meta-analysis provides a simple method of estimating the age of subjects of unknown birth date at the 10-year threshold. This is, presently, the most accurate method of age assessment for individuals of unknown date of birth.

Dental age assessment of adolescents and emerging adults in United Kingdom Caucasians using censored data for stage H of third molar roots.

The root of the third permanent molar is the only dental structure that continues development after completion of growth of the second permanent molar. It is claimed that the lack of a clearly defined end point for completion of growth of the third permanent molar means that this tooth cannot be used for dental age assessment. The aim of this study was to estimate the mean age of attainment of the four stages (E, F, G, and H) of root development of the third molar. The way in which the end point of completion of stage H can be identified is described. A total of 1223 dental panoramic tomographs (DPTs) available in the archives of the Eastman Dental Hospital, London, were used for this study. The ages of the subjects ranged from 12.6 to 24.9 years with 63 per cent of the sample being female. Demirjan's tooth development stages (TDSs), for the first and second molars, were applied to the third molars by a single examiner. For each of stages E, F, and G and for stage H censored data, the mean ages of the males and females were compared, separately within each tooth morphology type using the two sample t-test (P < 0.01). The same test was used to compare the mean ages of the upper and lower third molars on each side, separately for each gender. The mean age of attainment and the 99 per cent confidence interval (CI) for each TDS were calculated for each third molar. The final stage H data were appropriately censored to exclude data above the age of completion of root growth. The results showed that, for each gender, the age in years at which individuals attained each of the four TDSs was approximately normally distributed. The mean age for appropriately censored data was always lower than the corresponding mean age of the inappropriately censored data for stage H (male UR8 19.57, UL8 19.53, LL8 19.91, and LR8 20.02 and female UR8 20.08, UL8 20.13, LL8 20.78, and LR8 20.70). This inappropriately censored data overestimated the mean age for stage H. The appropriately censored data for the TDSs of the third molar may be used to estimate the age of adolescents and emerging adults assuming average growth and development and recent attainment of stage H.

Deaths associated with GA for dentistry 1948 - 2016: the evolution of a policy for general anaesthesia (GA) for dental treatment.

BACKGROUND: Following the inception of the National Health Service in 1948 dental treatment under General Anesthesia (GA) became easily available. An unexpected consequence of this was a disconcerting number of deaths associated with GA. Over the decades since 1948 there have been a number of specialist medical society, royal college, and government working parties deliberating on the appropriateness of GA being conducted in general dental practice and community dental practice. METHODS: The figures for the number of general anaesthetics per annum in England and Wales were obtained from the general dental services board, the community dental service, and records from hospital inpatient episodes. The number of deaths per annum were obtained from coroners' enquiries and dental protection societies. FINDINGS: Prior to 2001 there is a strong correlation between the number of GA's per annum and deaths. Since 2001, when the UK government directed that all GAs for dentistry must be administered in a hospital with Intensive Care facilities the number of deaths per annum has reduced to nil. INTERPRETATION: The change in the arrangements under which GA for dentistry are administered was coincident with improved training and knowledge of GA for dentistry. This has led to a cessation of deaths associated with GA for dentistry. The incidence rate is now estimated at less than 1 death per 3.5 million GAs.

Dental Age Assessment: a comparison of 4- to 24-year-olds in the United Kingdom and an Australian population.

BACKGROUND: The physiological age of a person is determined by the degree of maturation of the different tissue systems. Children of the same chronological age (CA) can demonstrate different degrees of maturation. Dental age (DA) is based on the maturation of teeth. Tooth formation is a continuous process, where the developmental stages of the tooth can be sequenced and defined depending on the degree of mineralization. These stages can be visualized on a dental panoramic tomograph (DPT). AIM: The aim of this study was to use a new method of Dental Age Assessment (DAA) to compare a United Kingdom (UK) and an Australian (AUS) population. DESIGN: The DPTs used are from the archives of the Westmead Centre for Oral Health (Westmead, Australia) and the King's College London Dental Institute. From the preliminary sample of 89 DPTs from each population, 77 were suitable for use as matched pairs. The radiographic technique used was developed by Demirjian and describes eight stages of tooth development. This was used in combination with numerical data derived from a meta-analysis of a single UK subject. RESULTS: A significant difference was shown between the CA and DA of the AUS patients. The AUS patients were also shown to have a significant 0.82 years delay in their DA compared to the UK patients. The findings indicate a difference in AUS compared to UK patients. These results indicate the need to develop a reference data set for the AUS population for DAA. CONCLUSIONS: This research is of significance in a number of clinical disciplines and can also be used to assist in age determination of subjects of unknown birth date to assist in forensic dentistry or social deliberations.

Antibiotics for the prophylaxis of bacterial endocarditis in dentistry.

BACKGROUND: Infective endocarditis is a severe infection arising in the lining of the heart with a high mortality rate.Many dental procedures cause bacteraemia and it was believed that this may lead to bacterial endocarditis (BE) in a few people. Guidelines in many countries have recommended that prior to invasive dental procedures antibiotics are administered to people at high risk of endocarditis. However, recent guidance by the National Institute for Health and Clinical Excellence (NICE) in England and Wales has recommended that antibiotics are not required. OBJECTIVES: To determine whether prophylactic antibiotic administration compared to no such administration or placebo before invasive dental procedures in people at increased risk of BE influences mortality, serious illness or endocarditis incidence. SEARCH STRATEGY: The search strategy from the previous review was expanded and run on MEDLINE (1950 to June 2008) and adapted for use on the Cochrane Oral Health, Heart and Infectious Diseases Groups' Trials Registers, as well as the following databases: CENTRAL (The Cochrane Library 2008, Issue 2); EMBASE (1980 to June 2008); and the metaRegister of Controlled Trials (to June 2008). SELECTION CRITERIA: Due to the low incidence of BE it was anticipated that few if any trials would be located. For this reason, cohort and case-control studies were included where suitably matched control or comparison groups had been studied. The intervention was the administration of antibiotic compared to no such administration before a dental procedure in people with an increased risk of BE. Cohort studies would need to follow those at increased risk and assess outcomes following any invasive dental procedures, grouping by whether prophylaxis was received. Included case-control studies would need to match people who had developed endocarditis (and who were known to be at increased risk before undergoing an invasive dental procedure preceding the onset of endocarditis) with those at similar risk but who had not developed endocarditis. Outcomes of interest were: mortality or serious adverse event requiring hospital admission; development of endocarditis following any dental procedure in a defined time period; development of endocarditis due to other non-dental causes; any recorded adverse events to the antibiotics; and cost implications of the antibiotic provision for the care of those patients who develop endocarditis. DATA COLLECTION AND ANALYSIS: Two review authors independently selected studies for inclusion, then assessed quality and extracted data from the included study. MAIN RESULTS: No randomised controlled trials (RCTs), controlled clinical trials (CCTs) or cohort studies were included. One case-control study met the inclusion criteria. It collected all the cases of endocarditis in The Netherlands over 2 years, finding a total of 24 people who developed endocarditis within 180 days of an invasive dental procedure, definitely requiring prophylaxis according to current guidelines and who were at increased risk of endocarditis due to a pre-existing cardiac problem. This study included participants who died because of the endocarditis (using proxys). Controls attended local cardiology outpatient clinics for similar cardiac problems, had undergone an invasive dental procedure within the past 180 days and were matched by age with the cases. No significant effect of penicillin prophylaxis on the incidence of endocarditis could be seen. No data were found on other outcomes. AUTHORS' CONCLUSIONS: There remains no evidence about whether penicillin prophylaxis is effective or ineffective against bacterial endocarditis in people at risk who are about to undergo an invasive dental procedure. There is a lack of evidence to support previously published guidelines in this area. It is not clear whether the potential harms and costs of antibiotic administration outweigh any beneficial effect. Ethically practitioners need to discuss the potential benefits and harms of antibiotic prophylaxis with their patients before a decision is made about administration.

Prevalence, intensity and nature of bacteraemia after toothbrushing.

OBJECTIVE: To estimate the prevalence, intensity and microbial identity of bacteraemia associated with toothbrushing. METHODS: A total of 141 children and adolescents, aged between 3 and 17 years, having dental treatment under general anaesthesia at the Eastman Dental Hospital were recruited. Six millilitre of blood was taken before toothbrushing (baseline) with (1) Oral B 30 toothbrush or (2) Braun or (3) Sonicare electric toothbrush or (4) dental handpiece and rubber cup. A second 6-ml sample was taken 30s after toothbrushing. All blood samples were processed using lysis filtration and bacteria were identified to species level. RESULTS: There was a significantly greater prevalence of bacteraemia following the dental handpiece only (p=0.02). There was a significantly greater aerobic and anaerobic intensity of bacteraemia following brushing with both the Sonicare (p=0.03 and p=0.05) and the dental handpiece (p=0.001 and p=0.005). CONCLUSIONS: Toothbrushing causes a bacteraemia that is often statistically significantly greater than baseline. Toothbrushing is an important contributory factor in cumulative dental bacteraemia.

Comparison of dental maturation in Hong Kong Chinese and United Kingdom Caucasian populations.

Understanding dental maturation in ethnically distinct populations is important in forensic age estimations and the presence of population differences in dental maturation was highly debated. No such comparison had been performed between two major populations; Caucasian and Chinese. This study aims to analyze and compare the maturation of permanent teeth from a sample of Caucasian and Chinese populations. Dental panoramic radiographs of subjects aged 2-24years belonging to United Kingdom (UK) Caucasian and Hong Kong (HK) Chinese populations were obtained from a teaching hospital. The teeth were scored and reference datasets were developed separately for males and females. Statistical significance was set at p<0.05 and independent sample t-test was conducted between the average ages at assessment for each stage of development for all the teeth in both groups. The HK Chinese were dentally advanced than the UK Caucasians by an average of 5 months, however, reverse trend was observed in third molars (p<0.05). These findings must be considered whilst utilising population specific reference dataset for dental age estimation.

Dental Age Estimation: Pattern Recognition of Root Canal Widths of Mandibular Molars. A Novel Mandibular Maturity Marker at the 18-Year Threshold.

The final stage of third molar development is used to assign a subject to above the 18-year threshold. Some subjects exhibiting this final stage are less than 18 years. Radiographs from 1000 females and 1000 males age 16.00-25.99 years were examined. Each half-year age band comprised 50 females and 50 males. Three categories of root canal widths (RCW) of the LL6, LL7, and LL8 [FDI 36, 37, and 38] were defined. Reproducibility was achieved by re-assessing the same subjects 12 months apart. For females, the minimum value for RCW-A was 16.33 years, RCW-B 17.23 years, and RCW-C 18.45 years. For males, the minimum values were RCW-A 17.16 years, RCW-B 18.29 years, and RCW-C 18.16 years. The presence of RCW-C in a female, and the presence of RCW-B or RCW-C in a male is compelling evidence that the subject is above the 18-year threshold.

Development of a Reference Data Set (RDS) for dental age estimation (DAE) and testing of this with a separate Validation Set (VS) in a southern Chinese population.

BACKGROUND: Many countries have recently experienced a rapid increase in the demand for forensic age estimates of unaccompanied minors. Hong Kong is a major tourist and business center where there has been an increase in the number of people intercepted with false travel documents. An accurate estimation of age is only possible when a dataset for age estimation that has been derived from the corresponding ethnic population. Thus, the aim of this study was to develop and validate a Reference Data Set (RDS) for dental age estimation for southern Chinese. MATERIALS AND METHODS: A total of 2306 subjects were selected from the patient archives of a large dental hospital and the chronological age for each subject was recorded. This age was assigned to each specific stage of dental development for each tooth to create a RDS. To validate this RDS, a further 484 subjects were randomly chosen from the patient archives and their dental age was assessed based on the scores from the RDS. Dental age was estimated using meta-analysis command corresponding to random effects statistical model. Chronological age (CA) and Dental Age (DA) were compared using the paired t-test. RESULTS: The overall difference between the chronological and dental age (CA-DA) was 0.05 years (2.6 weeks) for males and 0.03 years (1.6 weeks) for females. The paired t-test indicated that there was no statistically significant difference between the chronological and dental age (p > 0.05). CONCLUSION: The validated southern Chinese reference dataset based on dental maturation accurately estimated the chronological age.

Ages of legal importance: Implications in relation to birth registration and age assessment practices.

Assessment of age is a common procedure routinely conducted in many countries following birth date disputes, particularly following asylum claims and criminal offenses. UNICEF reports that only 65% of children in the world were registered, and the numbers of children who possess an authentic birth certificate were significantly lower than those registered. Legally important ages can be categorized into defined age ranges that vary among different countries. Recently, following an increase in the number of age-specific crimes, many countries have revised their legally important ages. This article is intended to report the most recent data on the ages of legal importance in the major countries of the world and implicate its relevance to birth registration and age assessment practices.

Northern Chinese dental ages estimated from southern Chinese reference datasets closely correlate with chronological age.

While northern and southern Chinese are genetically correlated, there exists notable environmental differences in their living conditions. This study aimed to evaluate validity of the southern Chinese reference dataset for dental age estimation applied to northern Chinese. Dental panoramic tomographs of 437 northern Chinese aged 3 to 21 years were analysed. All the left maxillary and mandibular permanent teeth plus the 2 third molars on the right side were scored based on Demirjian's classification of tooth development stages. Mean and standard error of dental age were obtained for each tooth development stage, followed by random effect meta-analysis for mean dental age estimation. Validity of the method was examined through measures of agreement (95% limits of agreement, standard error of measurement, and Lin's concordance correlation coefficient) and measure of reliability (Intraclass correlation coefficient). On average, the estimated dental age overestimated chronological age by only around 1 month in both females and males. The Intraclass correlation coefficient values were 0.99 for both sexes, suggesting excellent reliability of the method. Reference dataset for dental age estimation developed on the basis of southern Chinese was applicable for use among the northern Chinese.

Dental Age Estimation (DAE): Data management for tooth development stages including the third molar. Appropriate censoring of Stage H, the final stage of tooth development.

INTRODUCTION: The final stage of dental development of third molars is usually helpful to indicate whether or not a subject is aged over 18 years. A complexity is that the final stage of development is unlimited in its upper border. Investigators usually select an inappropriate upper age limit or censor point for this tooth development stage. MATERIALS AND METHODS: The literature was searched for appropriate data sets for dental age estimation and those that provided the count (n), the mean (x¯), and the standard deviation (sd) for each of the tooth development stages. The Demirjian G and Demirjian H were used for this study. Upper and lower limits of the Stage G and Stage H data were calculated limiting the data to plus or minus three standard deviations from the mean. The upper border of Stage H was limited by appropriate censoring at the maximum value for Stage G. RESULTS: The maximum age at attainment from published data, for Stage H, ranged from 22.60 years to 34.50 years. These data were explored to demonstrate how censoring provides an estimate for the correct maximum age for the final stage of Stage H as 21.64 years for UK Caucasians. CONCLUSION: This study shows that confining the data array of individual tooth developments stages to ± 3sd provides a reliable and logical way of censoring the data for tooth development stages with a Normal distribution of data. For Stage H this is inappropriate as it is unbounded in its upper limit. The use of a censored data array for Stage H using Percentile values is appropriate. This increases the reliability of using third molar Stage H alone to determine whether or not an individual is over 18 years old. For Stage H, individual ancestral groups should be censored using the same technique.

Environmental influences on the trace element content of teeth--implications for disease and nutritional status.

The aim of this study was to compare the trace element content of children's primary teeth from Uganda and the UK. The Ugandan teeth were from children living in an area where endomyocardial fibrosis (EMF), a cardiac disease, is prevalent. The latter has been putatively linked to insufficient magnesium intake and excess cerium exposure. Primary teeth were collected from 21 Ugandan and 27 UK children. The crowns and roots of the teeth were separated and the former digested and analysed for several major and trace elements by inductively coupled plasma mass spectrometry (ICP-MS) and atomic emission spectrometry (ICP-AES). In addition, the enamel and dentine of eight UK and seven Ugandan primary teeth were isolated via density separation and analysed as above. The data were assessed using non-parametric statistical tests. The Ugandan teeth contained significantly (P < 0.05) greater concentrations of strontium, barium, cerium, lanthanum, praseodymium and significantly less zinc than the UK teeth. No significant difference in the concentrations of aluminium, calcium, copper, magnesium, lead and uranium were found. Analysis of enamel and dentine demonstrated that the former was enriched with several elements including cerium. It is concluded, that the environment, influences the trace element content of primary teeth and this may be useful for monitoring nutritional status. With respect to a geochemical cause for EMF, there is no positive evidence that EMF in Uganda is associated with reduced magnesium and increased cerium uptake in primary teeth. This does not, however, exclude cerium from playing a role in the aetiology of EMF.

Advances in paediatric dentistry.

The problems facing paediatric dentists have not changed over the years, management of caries and orodental trauma still takes up the greatest proportion of their time. What has changed are the treatments available and in this paper some of the more interesting recent developments in this field are summarised.

The Weighted Average Method 'WAM' for dental age estimation: a simpler method for children at the 10 year threshold: "it is vain to do with more when less will suffice" William of Ockham 1288-1358.".

The mathematical principle of weighting averages to determine the most appropriate numerical outcome is well established in economic and social studies. It has seen little application in forensic dentistry. This study re-evaluated the data from a previous study of age assessment at the 10 year threshold. A semiautomatic process of weighting averages by n-td, x-tds, sd-tds, se-tds, 1/sd-tds, 1/se-tds was prepared in an Excel worksheet and the different weighted mean values reported. In addition the Fixed Effects and Random Effects models for Meta-Analysis were used and applied to the same data sets. In conclusion it has been shown that the most accurate age estimation method is to use the Random Effects Model for the mathematical procedures.

The French-Canadian data set of Demirjian for dental age estimation: a systematic review and meta-analysis.

BACKGROUND: Estimation of age of an individual can be performed by evaluating the pattern of dental development. A dataset for age estimation based on the dental maturity of a French-Canadian population was published over 35 years ago and has become the most widely accepted dataset. The applicability of this dataset has been tested on different population groups. AIM: To estimate the observed differences between Chronological age (CA) and Dental age (DA) when the French Canadian dataset was used to estimate the age of different population groups. MATERIALS AND METHODS: A systematic search of literature for papers utilizing the French Canadian dataset for age estimation was performed. All language articles from PubMed, Embase and Cochrane databases were electronically searched for terms 'Demirjian' and 'Dental age' published between January 1973 and December 2011. A hand search of articles was also conducted. RESULTS: A total of 274 studies were identified from which 34 studies were included for qualitative analysis and 12 studies were included for quantitative assessment and meta-analysis. When synthesizing the estimation results from different population groups, on average, the Demirjian dataset overestimated the age of females by 0.65 years (-0.10 years to +2.82 years) and males by 0.60 years (-0.23 years to +3.04 years). CONCLUSION: The French Canadian dataset overestimates the age of the subjects by more than six months and hence this dataset should be used only with considerable caution when estimating age of group of subjects of any global population.

Dental age assessment (DAA): a study of a Caucasian population at the 13 year threshold.

UNLABELLED: The purpose of this study was to develop a Reference Data Set for Dental Age Assessment at the 13 year old threshold in Caucasian children. PATIENTS, MATERIALS AND METHODS: The Reference Data Set comprised 5187 re-used Dental Panoramic Tomographs (DPTs) between the ages of 11-15 years, from both the Eastman Dental Hospital and King's College Dental Hospital archives. Tooth Development Stages were recorded for the left maxillary and mandibular teeth and all four permanent third molars (Demirjian et al., 1973, Demirjian 1978). A separate Study Sample of DPTs, comprising 50 males and 50 females aged between 10 and 16 years was collected to test the accuracy of the method. Summary Data was generated for the individual Tooth Development Stages which consisted of the number (n-tds), mean (x), standard deviation (sd) and the standard error (se). By using the mathematical techniques of meta-analysis, this data was used to estimate the age of each subject in the Study Sample. The estimated Dental Age derived was compared to the gold standard of Chronological Age. RESULTS: The mean difference between the Chronological Age and Dental Age was determined to be -0.1 years (-1.2 months) for males and 0.05 years (-0.6 months) for females. CONCLUSION: Dental Age was reliably estimated at the 13 year threshold.