Accuracy of four dental age estimation methodologies in Brazilian and Croatian children

ObjectiveTo compare and analyse the accuracy of four age estimation methods using the mineralisation stages of the permanent teeth (Cameriere et al. [16] [CAM], Liliequist and Lundberg [LLH] and Nolla without third molars [NOL7] or with them [NOL8]) in a mixed population of Brazilians and a homogeneous population of Croatians.MethodsOrthopantomograms of 930 Brazilians (366 males and 564 females) and 924 Croatians (365 males and 556 females) aged between 8 and 14.99 years were analysed using the CAM, LLH, NOL7 and NOL8 age estimation methodologies.ResultsLLH presented the best absolute differences (ADs) among both populations without sex stratification, while CAM presented the worst results. In addition, the mean differences revealed underestimations, except when the LLH and NOL7 methods were used for the Brazilians. When the sample was stratified by sex, the best AD values were found with NOL7 (0.80) for the Brazilians and with LLH (0.98) for the Croatians. When the sample was stratified by sex and age, CAM presented high accuracy at the early ages, and LLH presented high accuracy at the older ages. The results obtained with the Nolla methods (NOL7 and NOL8) were mostly similar, but NOL7 yielded slightly better results.ConclusionsThe values for the Brazilians and the Croatians were relatively similar, and the techniques were properly applied in both population samples. The best method for evaluating both countries was LLH, followed by NOL7, NOL8 and CAM.     

Accuracy of age estimation of radiographic methods using developing teeth

Developing teeth are used to assess maturity and estimate age in a number of disciplines, however the accuracy of different methods has not been systematically investigated. The aim of this study was to determine the accuracy of several methods. Tooth formation was assessed from radiographs of healthy children attending a dental teaching hospital. The sample was 946 children (491 boys, 455 girls, aged 3-16.99 years) with similar number of children from Bangladeshi and British Caucasian ethnic origin. Panoramic radiographs were examined and seven mandibular teeth staged according to Demirjian's dental maturity scale [A. Demirjian, Dental development, CD-ROM, Silver Platter Education, University of Montreal, Montreal, 1993-1994; A. Demirjian, H. Goldstein, J.M. Tanner, A new system of dental age assessment, Hum. Biol. 45 (1973) 211-227; A. Demirjian, H. Goldstein, New systems for dental maturity based on seven and four teeth, Ann. Hum. Biol. 3 (1976) 411-421], Nolla [C.M. Nolla, The development of the permanent teeth, J. Dent. Child. 27 (1960) 254-266] and Haavikko [K. Haavikko, The formation and the alveolar and clinical eruption of the permanent teeth. An orthopantomographic study. Proc. Finn. Dent. Soc. 66 (1970) 103-170]. Dental age was calculated for each method, including an adaptation of Demirjian's method with updated scoring [G. Willems, A. Van Olmen, B. Spiessens, C. Carels, Dental age estimation in Belgian children: Demirjian's technique revisited, J. Forensic Sci. 46 (2001) 893-895]. The mean difference (+/-S.D. in years) between dental and real age was calculated for each method and in the case of Haavikko, each tooth type; and tested using t-test. Mean difference was also calculated for the age group 3-13.99 years for Haavikko (mean and individual teeth). Results show that the most accurate method was by Willems [G. Willems, A. Van Olmen, B. Spiessens, C. Carels, Dental age estimation in Belgian children: Demirjian's technique revisited, J. Forensic Sci. 46 (2001) 893-895] (boys -0.05+/-0.81, girls -0.20+/-0.89, both -0.12 y+/-0.85), Demirjian [A. Demirjian, Dental development, CD-ROM, Silver Platter Education, University of Montreal, Montreal, 1993-1994] overestimated age (boys 0.25+/-0.84, girls 0.23+/-0.84, both 0.24 y+/-0.86), while Nolla [C.M. Nolla, The development of the permanent teeth, J. Dent. Child. 27 (1960) 254-266] and Haavikko's [K. Haavikko, The formation and the alveolar and clinical eruption of the permanent teeth. An orthopantomographic study, Proc. Finn. Dent. Soc. 66 (1970) 103-170] methods under-estimated age (boys -0.87+/-0.87, girls -1.18+/-0.96, both -1.02 y+/-0.93; boys -0.56+/-0.91, girls -0.79+/-1.11, both -0.67 y+/-1.01, respectively). For individual teeth using Haavikko's method, first premolar and second molar were most accurate; and more accurate than the mean value of all developing teeth. The 95% confidence interval of the mean was least for mean of all developing teeth using Haavikko (age 3-13.99 years), followed by identical values for Demirjian and Willems (sexes combined).     

利用牙齿推断年龄的研究进展

牙齿是人体最坚硬的器官之一,其抗腐蚀能力强,多项形态特征具有增龄性变化,因此利用牙齿推断年龄在法医学中得到广泛应用。由于牙齿的生理性变化的复杂性及环境因素的影响,不同牙齿推断年龄的方法各具其应用价值,同时也存在一定的局限性,法医工作者需要依据具体情况选择适合的方法并加以综合运用,以提高年龄推断的准确性。本文对国内外利用牙齿推断年龄的研究现状进行综述,并对各种推断方法进行比较评价,希望能为相关研究和实践提供参考。     

Reliability and validity of eight dental age estimation methods for adults

This paper evaluates the reliability and validity of eight published dental age estimation methods for adults that may aid in victim identification. Age was calculated on 20 Caucasian teeth of known age according to the methods of Kvaal (for in situ and extracted teeth), Solheim (for in situ and sectioned teeth), Lamendin (for extracted teeth), Johanson (for sectioned teeth) and Bang (for extracted and sectioned teeth) by one independent observer. For each method, mean age error and standard error were assessed as the measures of accuracy and precision. In addition, method simplicity, requirements for tooth preparation and the equipment necessary were assessed and recommendations given for forensic use in various situations. Methods for sectioned teeth gave more reliable results when compared to methods for intact teeth.     

运用牙齿影像学方法推断年龄的研究进展

本文对国内外文献在利用牙齿的影像学检查推断幼儿、青少年和成人年龄的方法、特点和优缺点进行了归纳和综述。     

Dental age estimation of Norwegian adults — A comparison of different methods

Age estimations were performed on 100 teeth according to the methods of Bang and Ramm (unsectioned and sectioned teeth), Miles, Johanson, and Dalitz, and in addition by visual examination of the unsectioned teeth. Mean error as well as standard and mean deviations were calculated. The method of Johanson was found to be slightly more reliable than the others. Visual estimation was also in some respects better than the other three methods. All methods resulted in the largest number of overestimates in teeth from persons below 40 years, from males, from the maxilla, and in teeth removed from corpses. Underestimates were predominant in teeth from persons above 50 years.     

Comparison of the validity of three dental methods for the estimation of age at death

The aim of the present study was to compare the accuracy, precision, and bias of two macroscopic and one histological age at death estimation methods on human teeth. The sample was comprised of 67 permanent teeth, obtained from 37 individuals aged 20-91 years. Age was predicted according to the methods proposed by Lamendin et al. (LAM), Bang and Ramm (BR), and the quantification of tooth cementum annulations (TCA). TCA was found to be most accurate in all age groups. Its mean absolute error of the estimated age was about half as high as the mean absolute error for both LAM and BR. BR achieved approximately the same mean absolute error as TCA for old adults only. LAM displayed the highest precision in the young and the old age group whereas TCA was more precise in the middle age group. TCA was found to be the most precise method when the precision was calculated for all ages. Considering the bias, all methods displayed a tendency to overestimate age in young and to underestimate it in old specimens. The exception to this rule was TCA, which provided unbiased estimates for young adults. The higher accuracy and precision recommends favouring TCA over LAM and BR, provided that the required know-how and equipment are available.     

应用Demirjian法进行法医学年龄推断的评价

目的对应用Demirjian法进行法医学年龄推断的准确度及可靠性进行初步评价。方法应用Demirjian法测定828名上海地区青少年(男279名,女549名,11～19周岁)的牙龄,比较所测牙龄和实际年龄的差异。结果在11～14岁年龄段Demirjian法测定的牙龄比实际年龄高估,在15～16岁年龄段低估,在17岁及17岁以上年龄段具有局限性。结论Demirjian法可以用于测定上海地区11～16岁年龄段青少年的牙龄,使用时需进行适当的修正。     

Age estimation of Korean children based on dental maturity

The aim of this study was to evaluate the relationship between age and dental maturity and to establish the standard database of dental maturity based on the Demirjian's stages, which can be used for the age estimation of Korean children. For this purpose, dental maturity was measured by the Demirjian's stages on a randomly selected sample of panoramic radiographs taken from 2706 patients between 1 and 20 years of age and analyzed by multiple linear regression analysis based on the method of least squares. The results showed that, except for the third molars, the development of permanent teeth in Korean children was more advanced in females. The Demirjian's stage G of the second molar appeared last in both male and female subjects by age 18, showing 95th percentile at age in the male and female subjects between 16.7-17.4 years and 17.1-17.3 years, respectively. Coefficients of determination (r(2)) of the Demirjian's stages relative to age in regression analysis were 0.9721 in male and 0.9740 in female subjects. The standard error was 0.63 years in male and 0.62 years in female subjects. The estimated age according to regression analysis was within +/-1.0 year of the actual age in 92.0% of male and 92.5% of female subjects. Collectively, the data of the present study can be used as a reference for dental maturity and a standard for age estimation of Korean children.     

两种骨龄标准推断女性14岁年龄的准确度

目的研究李果珍百分计数法和中国人手腕骨发育标准CHN法在推断女性14岁年龄时的准确度。方法在湖南娄底三所中学随机选择51名14岁女生,同一条件下拍摄左手腕X线片;按照上述两种方法由专业人员阅片;对比两种方法所得结果及其与真实年龄间的差异。结果计数法和CHN法测得的骨龄与研究对象的实际年龄间无显著性差异(P>0.05),两种方法比较也未见明显差异(P>0.05)。结论计数法和CNH法可用于湖南地区女性14岁年龄的推断。     

Application of Cameriere’s method for dental age estimation in children in South China

The aim of this study was to evaluate the applicability of Cameriere’s European formula for age estimation in children in South China and to adapt the formula to establish a more suitable formula for these children. Moreover, the performance of dental age estimation based on Cameriere’s method combining the developmental information of permanent teeth (PT) and third molar (TM) was also analysed. Orthopantomographs of 720 healthy children in Group A, and orthopantomographs of 320 children and 280 subadults in Group B were assessed. The samples of Group A were divided into training dataset 1 and test dataset 1, and the samples of Group B were also divided into training dataset 2 and test dataset 2. A South China-specific formula was established based on the training dataset 1, and the comparison of accuracy between the Cameriere’s European formula and the South China-specific formula was conducted with the test dataset 1. Additionally, a PT regression model, a TM regression model, and a combined regression model (PT + TM) were established based on the training dataset 2, and the performance of these three models were validated on the test dataset 2. The Cameriere’s European formula underestimated chronological age with a mean difference (ME) of −0.47 ± 1.11 years in males and −0.69 ± 1.19 years in females. However, the South China-specific formula underestimated chronological age, with a mean difference (ME) of −0.02 ± 0.71 years in males and −0.14 ± 0.73 years in females. Compared with PT model and TM model, the PT and TM combined model obtained the smallest root mean square error (RMSE) of 1.29 years in males and 0.93 years in females. In conclusion, the South China-specific formula was more suitable for assessing the dental age of children in South China, and the PT and TM combined model can improve the accuracy of dental age estimation in children.

Key points

• Orthopantomographs of 720 healthy children in Group A, and orthopantomographs of 320 children and 280 subadults in Group B were assessed.
• A South China-specific formula was established based on the training dataset 1, and the comparison of accuracy between the Cameriere’s European formula and the South China-specific formula was conducted with the test dataset 1.
• A PT regression model, a TM regression model, and a combined regression model (PT + TM) were established based on the training dataset 2, and the performance of these three models were validated on the test dataset 2.
• The South China-specific formula was more suitable for assessing the dental age of children in South China, and the PT and TM combined model can improve the accuracy of dental age estimation in children.

     

Application of three dental methods of adult age estimation from intact single rooted teeth to a Peruvian sample

Methods of estimating adult age at death from such dental features as root translucency, root length, and the extent of periodontosis in intact single rooted teeth have proven useful in studies of modern individuals, especially in estimating age in older adults. Questions remain however, concerning the impact of regional and population variation on accuracy. To examine this issue, three approaches to age estimation were applied to a diverse sample of 100 individuals from Peru. Mean errors of estimation for all three approaches were similar to those originally reported, suggesting minimal impact of population variation of the features measured. A new regression equation, specifically for Peruvian samples, is provided.     

Objective measurement of dental color for age estimation by spectroradiometry

Age-related changes in tooth color have been described previously, however, the use of dental color for age estimation in forensic odontology has been limited due to the difficulty of measuring color objectively. This study presents an objective method for determining dental color to estimate the age of an individual. Dentine color in 250 teeth from patients ranging in age from 10 to 89 years was determined by spectroradiometry. Color measurements were performed as suggested in the CIE 1931 (International Commission on Illumination). Chromaticity coordinates (x, y, z), luminance (Y), whiteness index (WIC, Z%, WIC) and yellowness index (YI) were obtained. Correlations between these colorimetric variables and aging were established by linear regression analyses. All the variables fit the mathematical model with correlation coefficients ranging from 0.53 to 0.75. This method of color measurement produced an expected associated error of calibration averaging 13.7 years about the mean estimated values, at a 70% level of confidence. Two different multiple regression models for dental age estimation were tested, and variables that made the greatest contributions to age calculation were identified. To determine the effect of postmortem interval on tooth color and its influence in age estimation, 37 teeth obtained from human skeletal remains buried during an interval ranging from 21 to 37 years were also studied. In this material, the correlation between age and dental color measured by spectroradiometry was weaker than in fresh extracted teeth.It is concluded that determination of dentine color by spectroradiometry is a potentially useful objective method to estimate age in forensic studies in combination with other methods.     

中国北方未成年人群牙龄推断研究

目的 运用Cameriere法和Willems法推断中国北方5～14岁人群牙龄,并比较两种方法牙龄推断的准确性.方法 收集西安交通大学口腔医院年龄在5～14岁的中国北方未成年人群拍摄的全口曲面断层片2000例,其中男性1000例,女性1000例.分别采用Cameriere法和Willems法进行牙龄推断,利用SPSS ...     

Model of age estimation based on dental factors of unknown cadavers among Iranians

Two hundred and ten cadavers ranging in age from 25 to 60 were studied. Thirty subjects from each five-year interval were selected, and data were collected using the mandibular anterior and premolar teeth after extraction. Sections ranging from 0.5 to 1.0 mm were measured by a stereo microscope with a precision of 0.1 mm. The following factors were determined: attrition, periodontosis, root resorption, secondary dentine apposition, cementum apposition, and translucency of the root. Statistical analysis used the sum of ranks of the dental factors as an independent variable in a linear regression model to estimate the age of the cadaver. Among the different mandibular teeth, the sum of ranks of the first premolar factors had the best correlation coefficient with age. The sum of the dental factors presented a better model than each of the factors alone. The first premolar is recommended as the first step in the estimation of age.     

青少年活体年龄推断的方法比较

目的探讨准确推断青少年活体年龄的方法。方法对233名青少年活体年龄鉴定案所涉及的案件性质、作案距鉴定的间隔时间、自报年龄与鉴定年龄差距等进行归类、分析,并就其中130名骨骺尚未完全愈合的男性青少年的年龄,用多元回归方程法、CHN计分法和本文作者设计的综合法分别进行推断,统计前两个方法与综合法的符合率。结果 归类分析显示:本组资料,刑事案件当事人的涉案性质,抢劫、抢夺的占72.10％;作案距鉴定的间隔时间小于6个月的占75.10％;自报年龄小于鉴定年龄的占60.73％。用多元回归方程法、CHN计分法鉴定年龄与综合法鉴定年龄的符合率分别为90.77％与83.08％。结论活体年龄鉴定应在作案后尽早进行;用多元回归方程法鉴定18岁左右的年龄较CHN计分法准确,采用综合法鉴定年龄可能更好。     

常用女性青少年骨龄评定方法的比较

目的 对常用骨龄评定方法进行比较分析,以评价其在判定骨龄精确度、实用性等方面的差别,为法医办案提供参考.方法 选取河南省某县145名女性青少年作为研究对象,拍摄全身左侧六大关节X线片870张.分别采用百分计数法、CHN法、六大关节法、图谱法、叶氏评分法评定145名个体骨龄.采用SPSS ver.11.5软件包进行统计、分析.结果 CHN法、六大关节法、图谱法评定的骨龄与时间年龄无显著性差异(P＞0.05)；百分计数法和叶氏评分法评定的骨龄与时间年龄有显著性差异(P＜0.05).CHN法、六大关节法、图谱法评定的骨龄之间无显著性差异(P＞0.05),百分计数法、叶氏评分法评定的骨龄相互之间及与其他方法之间存在显著性差异(P＜0.05).结论 六大关节法评定女性青少年的骨龄精确度最高,CHN法和图谱法评定我国女性青少年骨龄较实用.     

Dental age assessment: the applicability of Demirjian method in eastern Turkish children

In the literature, little is known about the applicability of this method in Turkish children. The aim of this study was, therefore, to evaluate the reliability of Demirjian method of age estimation when used for eastern Turkish children. A retrospective study was performed on a sample of panoramic radiographs taken from 807 healthy eastern Turkish children. The stages of dental maturity of the mandibular left seven permanent teeth for each subject using the eight radiographic dental maturity stages demonstrated by Demirjian were evaluated. A paired t-test was used for statistical analysis. The mean difference between the chronological and dental ages ranged from 0.2 to 1.9 years in girls and from 0.4 to 1.3 years in boys. The differences between the chronological and dental ages were statistically significant in all age groups. The applicability of Demirjian method is not suitable for eastern Turkish population.     

Comparing the accuracy of Demirjian and Nolla methods and establishing a new method for dental age estimation in northeastern Chinese children

Dental age estimation plays an important role in the field of clinic medicine and forensic medicine. The Demirjian and Nolla methods are common scoring methods for dental age estimation but there was no research about the comparison of accuracy of these two methods in northeastern Chinese children. Hence, in this study, we compared the accuracy of these two methods to explore more suitable method for our studied population. We collected 535 orthopantomograms from northern Chinese children aged from 6 to 15 years and divided them into training dataset and testing dataset according to the ratio of 7:3. The dental age of training dataset were estimated using Demirjian and Nolla methods, respectively. The results suggested that the mean differences of these two methods were 0.24 and −0.40 years, and mean absolute difference were 0.65 and 0.59 years. Then to further improve the accuracy of dental age assessment, the new improved formulas and dental age conversion tables were established after analyzing the relationship between the sum scores based on Nolla method and chronology age in training dataset. According to the new method used in testing dataset, the minimum value of mean difference (0.00) and mean absolute difference (0.49) were obtained, which are largely smaller than that of Demirjian and Nolla methods. The new developed method and dental age conversion scales may be more suitable dental age estimation method for northeastern Chinese children.