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ORIGINAL ARTICLE
Year : 2018  |  Volume : 21  |  Issue : 3  |  Page : 257-263

Accuracy of the demirjian, willems and cameriere methods of estimating dental age on turkish children


1 Pamukkale University, Faculty of Dentistry, Department of Maxillofacial Radiology, Denizli, Turkey
2 Selcuk University, Faculty of Dentistry, Department of Maxillofacial Radiology, Konya, Turkey

Date of Acceptance09-Jan-2017
Date of Web Publication09-Mar-2018

Correspondence Address:
Dr. B K Apaydin
Pamukkale University, Faculty of Dentistry, Department of Maxillofacial Radiology, Denizli
Turkey
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Source of Support: None, Conflict of Interest: None


DOI: 10.4103/1119-3077.226966

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   Abstract 


Background and Aim: Age estimation plays a significant role in forensic science, archeology, pediatric endocrinology and clinical dentistry. Tooth development is a reliable pathway for age estimation, especially in children. The aim of this study was to evaluate the accuracy of the Demirjian method (DM), Willems method (WM) and Cameriere method (CM). Materials and Methods: This study included panaramic radiographs of 330 individuals (165 girls, 165 boys) aged between 5 and 15.90 years. The differences between chronological age (CA) and the estimated dental age (DA) were statistically tested using a paired sample t-test and the Wilcoxon signed rank test. Results: The mean prediction error showed that; the DM overestimated the DA by 0.304 years, the WM underestimated the DA by -0.060 years and the CM underestimated the DA by -0.580 years. The difference between CA and estimated DA was not statistically significant according to WM (p = 0.074) and statistically significant according to DM and CM (p < 0.001). Conclusion: In conclusion, this study indicated that WM determines DA satisfactorily in a Turkish subpopulation.

Keywords: Age Determination by teeth, cameriere method, demirjian method, forensic dentistry, forensic science, panoramic radiography, willems method


How to cite this article:
Apaydin B K, Yasar F. Accuracy of the demirjian, willems and cameriere methods of estimating dental age on turkish children. Niger J Clin Pract 2018;21:257-63

How to cite this URL:
Apaydin B K, Yasar F. Accuracy of the demirjian, willems and cameriere methods of estimating dental age on turkish children. Niger J Clin Pract [serial online] 2018 [cited 2018 Sep 23];21:257-63. Available from: http://www.njcponline.com/text.asp?2018/21/3/257/226966




   Introduction Top


Estimating age plays a significant role in forensic odontology, since it is applied to the living and the dead.[1]

In case of unidentified bodies, age estimation facilitates the identification and comparison of the same with other missing persons. For the living, age estimation might help provide information about a person's status with regards to adoption, criminal responsibility, child pornography, asylum, civil matters, or when identification documents are missing.[2],[3],[4] Additionally, DA is very important in pediatric dentistry and orthodontics for diagnosis as well as planning the treatment.[5]

Various methods based on dental tissues including morphologic (dental attrition rate, tooth color changing), metric (Carbon-14 analysis, histologic analysis), radio morphologic (DM, WM, etc.), radiometric (CM, Mörnstaad' method) are available for age estimation.[6]

One of the most frequently used methods is the DM, which was first developed in 1973 in a French/Canadian subpopulation.[7] This method calculates DA by evaluating the eight development stages of the seven left mandibular teeth. The DM's well-defined stages and objectivity make it one of the most suitable methods for forensic science,[3] and its reliability has been tested on several populations.[2],[5],[8],[11] However, this method has generally overestimated CA,[2],[5],[8],[9],[10],[11] and the DM was modified, simplified by Willems et al. since it overestimates CA.[10],[12] Several researchers have reported that the WM provides more accurate age predictions.[8],[10],[13] In 2006, Cameriere et al. described a linear regression formula for estimating DA based on the measurements of the open apices and tooth length of seven left mandibular teeth in an Italian subpopulation.[14] Recently, several researchers have reported that the CM is accurate and useful for assessing DA in some countries.[14],[15],[16],[17],[18]

This is the first study that compares the DM, WM and CM on the same group of children in Turkish population. The aim of the present study was to evaluate the accuracy of the DM, WM and CM in a sample of Turkish children.


   Materials and Methods Top


The study was approved by the Research Ethics Committee of Selcuk University, Faculty of Dentistry, Konya, Turkey (2012/12-27).

Individuals aged between 5 and 15.90 years with good and clear panoramic radiographs and normally erupted teeth were included in the study. Individuals who have; developmental, endocrine or nutritional disorders, history of orthodontic treatment, dental anomalies, missing teeth on the left side of the mandible and cavities in one of the seven left mandibular teeth were excluded from the study.

Three hundred thirty panoramic radiographs (165 boys and 165 girls, aged from 5 to 15.90 years) that fulfilled these criteria were selected from the patient records database of Selcuk University, Faculty of Dentistry, Department of Maxillofacial Radiology and Department of Pediatric Dentistry, Konya, Turkey. The panoramic radiographs were made by the same radiography technician using Kodak 8000 equipment (Kodak 8000 Digital Panoramic System, Trophy Radiologies, Carestream Health Inc., NY, USA).

The patients' CA was calculated by subtracting the birthdate from the date on which the radiograph was made. A total of 330 panoramic radiographs were divided into 11 groups according to chronological ages (from 5 to 15.90 years). Each group consisted of 30 panoramic radiographs; 15 boys and 15 girls. Birth dates of the children were not disclosed to the researcher to avoid bias during the analysis of the dental stages.

DA was estimated on the panoramic radiographs using DM,[7] WM,[12] and CM.[14] DA was evaluated by DM using the Demirjian sex-specific tables [Table 1] and [Table 2], which divide the mineralization process of the seven left mandibular teeth (incisors, premolars, first and second molars) into eight stages from A to H [Figure 1] and [Figure 2]. After the particular stage of each tooth had been determined, these stages were converted into scores, and the total score gave the DA.
Table 1: Tooth mineralization scores according to Demirjian method (for boys).[7]

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Table 2: Tooth mineralization scores according to Demirjian method (for girls).[7]

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Figure 1: Schematic representation of the eight stages of tooth development from A to H as presented by Demirjian et al.[7]

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Figure 2: This panoramic image of an 8.9-year-old girl shows the different mineralization stages of the Demirjian method. After the stages for the seven left mandibular teeth had been determined, the stages were converted into Demirjian Mineralization Scores. The sum of the seven scores was converted into dental age according to the Demirjian Maturity Score Table (in this example 9.2 years). According to the Willems method, the sum of the seven already determined scores gave the dental age (in this example 8.9 years).

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WM[12] uses the Demirjian tooth mineralization stages to adjust scores. These scores were then converted into years by using the Willems sex-specific tables [Table 3]and [Table 4] and the total number of years gave the dental age.
Table 3: Tooth mineralization scores converted into age according to Willems method (for boys).[12]

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Table 4: Tooth mineralization scores converted into age according to Willems method (for girls).[12]

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The last age estimation method is that of Cameriere.[14] Initially, the degree of apical closure and the root lengths of the seven left mandibular teeth were measured. The distance between the inner surfaces of the apex openings for the teeth with one root was measured (Ai; i=1,……,5). The sum of the distances between the inner surfaces of the two apex openings for the teeth with two roots was measured (Ai, i = 6, 7) [Figure 3]. The Xi value was calculated to normalize the effect of possible differences in magnification and angulation among the radiographs (Xi= Ai/Li). The data obtained from this calculation was adapted with the following formula, which uses regression analysis developed by Cameriere[14]:
Figure 3: This panoramic image of an 8.9-year-old girl shows the measurements of the tooth lengths and the inner sides of the open apex. The dental age was calculated as 9.2 years by making use of the Cameriere formula.

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Age = 8.971 + 0.375.g + 1.631.X5 + 0.674.N0 - 1.034.s - 0.176.s.N0,

where,

(s): the sum of the Ai/Li of the open apices

(N0): the number of teeth with complete root development

(g): 1 for boys and 0 for girls

(X5)=A5/L5

CA was subtracted from the DA: A positive result indicated an overestimation, and a negative result indicated an underestimation of age.

The panoramic radiographs, which were recorded in TIFF (Tagged Image File Format), were evaluated on a widescreen computer monitor in a dark room. All measurements were obtained with the Image J program (×150 magnification) and performed by the same researcher. To assess the repeatability (intra-observer error) of this analysis, all of 330 panoramic radiographs were re-evaluated after four weeks.

Statistical analysis

Statistical analysis was performed using the SPSS v.20.0 for Windows (SPSS, Inc., Chicago, IL). Each of the 11 groups was assessed individually for normal distribution by Kolmogorov-Smirnov test. When parametric test assumptions were provided, paired samples t-test were used for intragroup comparisons. If assumptions were not provided, Wilcoxon signed rank test was used. The differences between CA and estimated DA were compared based on age and sex with the paired t-test and the Wilcoxon signed-rank test. The Wilcoxon signed-rank test was performed to analyze the evaluation results. The mean error was used to determine the accuracy of the three methods. The accuracy of the estimated DA was defined by how close it was to the CA. To calculate the accuracy of the age estimation method, the estimated DA was subtracted from the CA to obtain the mean prediction error. p<0.05 values were considered statistically significant. Correlation coefficients were used to evaluate the intra-observer consistency. Groups which showed normal distribution were evaluated by Pearson's correlation coefficient, and those which showed non-normal distribution were evaluated by Spearman Rank correlation coefficient. Second assessment results were used in the statistical analysis.


   Results Top


The mean age of the 330 children was 10.49 years (min = 5, max = 15.90). When they were grouped according to sex, the mean age was 10.50 years for boys (min = 5, max = 15.90) and 10.49 years for girls (min = 5.20, max = 15.90). High correlations were found between the first results and the results that were evaluated four weeks later (r = 0.948 for DM, 0.957 for WM, 0.930 for CM).

The accuracy of the DA was computed by the mean prediction error. For the total group, DM overestimated the children's CA, and the mean prediction error was 0.304 (for boys 0.310, for girls 0.300) years. WM underestimated the children's CA, and the mean prediction error was -0.060 (for boys -0.056, for girls -0.062) years. CM underestimated the children's CA, and the mean prediction error was -0.580 (for boys -0.603, for girls -0.550) years. As shown in [Table 5], the WM was more accurate than the DM and CM, with a lower mean difference in years between estimated dental and chronological ages.
Table 5: Mean differences in years between dental age and chronological age with Demirjian, Willems, and Cameriere methods and p value for per age groups.

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No statistical differences were found between CA and estimated DA according to the WM (p = 0.074; for boys, p = 0.199, for girls, p = 0.220). The statistical difference between the CA and DA according to the DM and CM were significant (p < 0.001).


   Discussion Top


The Study Group on Forensic Age Diagnostics (AGFAD) recommends the use of three independent methods for estimating CA.[15] These methods include physical examination, radiographic examination of the left hand, and dental examination. In the present study, we used methods that evaluate the stages of dental development as the teeth are maintained longer than bone, and dental development is less affected by environmental, genetic factors in comparison to skeletal development.[15] The complicated process of tooth development continues from early fetal life to the approximate age of 20 years.[1]

Different types of dental radiographs have been used to evaluate dental development. The use of panoramic radiographs to evaluate DA has been adopted by most researchers because of availability and ability to view all the teeth.[19] Panoramic radiographs are also the best tool for estimating age in children since intraoral radiographs are difficult to obtain without image distortion.[20] Thus, we used panoramic radiographs.

The DM uses the left side of mandible since studies indicate that the rate of growth is approximately the same on both sides.[10],[17] Several studies[2],[5],[8],[9],[10],[11],[12],[19],[20],[21],[22],[23],[24],[25],[26],[27],[28],[29],[30],[31] have been conducted to determine the accuracy of the DM in a specific population. In this study, DM overestimated the mean DA by 0.304 years (0.300 years for girls and 0.310 years for boys, ranging from -0.19 to 0.98 years), except for the 9-year-old group, which was underestimated by 0.19 years. These results show that growth in our population occurs later than in the French/Canadian population sample studied by Demirjian et al. The results of other studies from several countries that used the DM also showed an average overestimation in DA ranging from -0.750 to 3.04 years [Table 6].[2],[5],[8],[9],[10],[11],[12],[19],[20],[21],[22],[23],[24],[25],[26],[27],[28],[29],[30],[31]
Table 6: Previous reports that show mean prediction errors, comparing Demirjian, Willems and Cameriere methods in different populations (Positive results show overestimation, negative results show underestimation)

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Although Hagg and Mattson[32] reported that the DM was highly accurate in younger age groups, the results in this study do not support this. In this study, the largest discrepancy between dental and chronological ages was observed in the 5 to 5.90 and 6 to 6.90 age groups. This result was similar to that of other Turkish studies, namely, Celikoglu et al.,[25] Tunç and Koyuturk,[11] and Celik et al.[21] Growth prediction uncertainties in younger children may have caused this higher overestimation.[11]

The second largest discrepancy between dental and chronological ages in DM was in the group of 11 to 11.90 year-old girls in our study. Prepubertal or pubertal growth changes may explain this situation.

Willems et al. adopted and simplified the DM in Belgian children,[12] and, according to Liversidge, the WM showed more accurate results in estimating DA.[26] For that reason, we used the WM.

In this study, the DA was underestimated 0.060 year (0.062 year for girls and 0.056 year for boys) by WM; ranged from -0.68 to 0.32 year. DA differences in other studies that were found by authors using WM[12] was ranged from -0.69 to 0.55 year [Table 6].[2],[6],[8],[9],[10],[13],[16],[20],[22],[29],[30],[31],[33],[34],[35]

Liversidge et al.[26] believed that overestimated dental ages in recent studies using DM can be partly explained by a positive secular trend in growth and development since 1973. WM showed more accurate results in this study than the DM. This result could be explained by the fact that our study was performed 43 years after Demirjian's study and 15 years after Willems' study.

In this study, the CM underestimated the DA by 0.580 years (0.550 years for girls and 0.603 years for boys) ranged from -1.99 to 0.34 year. Differences ranging from -0.49 to 0.10 year [Table 6][14],[15],[16],[17],[18],[22],[23],[36] in DA were found in other populations by authors using the CM.[14] In the present study, in the 13-, 14-, and 15-year-old groups; the underestimations were more than a year with the CM. This higher underestimation was explained by the difficulty in measuring of small apex opening since the teeth in this age group are almost completely mature. In the present study, the CM estimated age more accurately in younger children. The differences were statistically significant for most of the age groups for both sexes.

The range of differences found in several studies from several countries might be explained by ethnic differences, climate nutrition, socio-economic level, sample size, and statistical methods.[19],[24]

In forensic science, the acceptable age difference between the DA and CA is reported as ± 1.00 year for children until adolescence.[8],[37] In this study, only in 13-, 14-, and 15-years old age groups that are evaluated by CM were overestimated by more than one year. According to this criterion, in the present study, WM and DM for estimating age are appropriate and recommended for Turkish children ranging in age from 5 to 15 years old. WM showed the most accurate results.

Financial support and sponsorship

This research was supported by the Scientific Research Projects Coordination Unit of Selcuk University Faculty of Dentistry, Konya, Turkey (no: 2012/12-27)

Conflicts of interest

There are no conflicts of interest.



 
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    Figures

  [Figure 1], [Figure 2], [Figure 3]
 
 
    Tables

  [Table 1], [Table 2], [Table 3], [Table 4], [Table 5], [Table 6]



 

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