Journal of Orofacial Sciences

ORIGINAL ARTICLE
Year
: 2018  |  Volume : 10  |  Issue : 2  |  Page : 63--68

Age Estimation by Modified Demirjian’s Method in Children and Adolescents of Hyderabad Population—A Panoramic Study


M. Priyanka, G. Kiran, R. Poornima, R. Shravani, K. C. Shobhita, P. Preethi 
 Department of Oral Pathology, Government Dental College and Hospital, Hyderabad, Telangana, India

Correspondence Address:
Dr. G. Kiran
Department of Oral and Maxillofacial Pathology, Government Dental College and Hospital, Hyderabad, Telangana, 500012
India

Abstract

Introduction: Human identification is one of the most important tasks of forensic practitioner. Estimation of age is one of the essential factors which play a significant role in each aspect of life, including forensic medicine and dentistry, wherein race, age, and sex determination are used in person identification. Aims and Objectives: To correlate the relationship between chronological age (CA) with dental age (DA) using modified Demirjian’s method and to establish the applicability of modified Demirjian’s method in Hyderabad population. Materials and Methods: Our study samples consist of 113 randomly selected samples (39 males and 74 females) of age ranging from 8 to 20 years of Hyderabad population for children and adolescents. Panoramic radiographs of these patients were evaluated based on the modified Demirjian’s method. The obtained data were tabulated and analyzed using SPSS version 20.0. Results: The present study showed a significant correlation between CA and DA in both females (r = 0.84) and males (r = 0.882). The overall mean difference between the DA and CA for females and males was +1.14 and +0.86, respectively. In the whole sample, DA was found to be over estimated by +1.04 with CA. Conclusion: DA overestimated the CA by +1.04 years. According to the present study, there was a difference and overestimation of DA in comparison with CA in Hyderabad population and hence population specific formula for each area is necessary.



How to cite this article:
Priyanka M, Kiran G, Poornima R, Shravani R, Shobhita KC, Preethi P. Age Estimation by Modified Demirjian’s Method in Children and Adolescents of Hyderabad Population—A Panoramic Study.J Orofac Sci 2018;10:63-68


How to cite this URL:
Priyanka M, Kiran G, Poornima R, Shravani R, Shobhita KC, Preethi P. Age Estimation by Modified Demirjian’s Method in Children and Adolescents of Hyderabad Population—A Panoramic Study. J Orofac Sci [serial online] 2018 [cited 2019 Mar 21 ];10:63-68
Available from: http://www.jofs.in/text.asp?2018/10/2/63/249093


Full Text



 Introduction



Dental identification is one among the various important factors in identifying a person’s age. As the time passes by, both teeth and dental restorations are considered as only means of identification.[1] Age estimation is one of the most important factors employed in establishing the identity of an individual, and it is performed for various reasons such as mass disasters such as fire accidents and crashes. In living person, determining the age is vital in individuals without birth certificate, who are getting married, attending school, joining the army, and also in the determination of criminal liability such as in incidents such as rape, kidnapping, illegal immigration, premature births, orthodontic malocclusion, and pediatric endocrinopathy.[2],[3]

Among the various parts of the body, teeth are most commonly used and most reliable indicator in age determination, as tooth is more resistant to taphonomic process after death.[4],[5] Their durability means that they are sometimes the only body part available for the study. Several methods have been used to estimate the dental age (DA) such as Cameriere’s, Willem’s, and Demirjian’s method for children and adolescents, Kvall’s technique for elder people. DA estimation using dental calcification and maturity is better than eruption of teeth, because it is not affected by local factors, such as impaction and crowing of permanent teeth, infections, lack of space, ankylosis, and early and delayed extraction of deciduous teeth.[6]

In 1973, Demirjian, Tanner, and Goldstein published the Demirjian’s method of age estimation, and it is one of the most frequently used methods for age estimation.[2],[7] According to the study, a common finding is overestimation of DA when compared to chronological age (CA), and underestimation was also noted. Several authors subsequently modify the original Demirjian’s methods. The present study was conducted to using modified Demirjian’s method and to evaluate the relationship between DA and CA.

 Materials and Methods



The study was carried on children and adolescents attending the outpatient department at Government Dental College and Hospital, Hyderabad, after obtaining institutional ethical clearance and informed consent from the patients. The age of included patients ranged from 8 to 20 years. Digital panoramic radiographs [[Figure 1] and [Figure 2]] without radiographic artifacts of 113 patients (39 boys, 74 girls) were evaluated as per the modified Demirjian’s method.{Figure 1}{Figure 2}

Inclusion criteria

Availability of complete patient record (date of birth and date of exposure),Age between 8 and 20 years,No systemic diseases affecting growth,No history of previous orthodontic treatment.

Exclusion criteria

Patients with orthodontic appliances,History of bilateral extractions,History of no trauma,Developmental abnormalities,Physically or mentally challenged children,Gross malocclusion.

Methodology

We followed modified Demirjian’s method, in which each tooth stage was rated based on a 10-stage scale from 0 to 9. The stages are “Stages (0–9)” of tooth formation [[Figure 3]].Stage 0: Tooth not at been calcified.Stage 1: Crypt stage, bony crypt is visible without dental germ inside.Stage 2: A beginning of calcification at the superior level of the crypt. No fusion of these calcified points.Stage 3: Fusion of the calcified points from one or several cusps which unite to give a regularly outlined occlusal surface.Stage 4:Enamel formation has been completed at the occlusal surface. Its extension and convergence toward the cervical region is seen.Dentine formation has commenced.The pulp chamber is curved, and no pulp horns are visible.Stage 5:Crown formation has been completed.The superior border of the pulp chamber in uniradicular teeth has a definite curved form, being concave toward the cervical region. The projection of the pulp horns, if present, gives an outline shaped like an umbrella top. In molars, the pulp chamber has a trapezoidal form.Beginning of root formation is seen in the form of a spicule.Stage 6:Uniradicular teethThe walls of the pulp chamber now form straight lines, whose continuity is broken by the presence of the pulp horn, which is larger than in the previous stage.The root length is shorter than the crown height.Multiradicular teethInitial formation of the radicular bifurcation is seen in the form of either a calcified point or semilunar shape.The root length reaches at least one-third of the crown height.Stage 7:Uniradicular teethThe walls of the pulp chamber now form an isosceles triangle. The apex ends in a funnel shape.The root length is equal to or greater than the crown height.Multiradicular teethBifurcation has developed sufficiently to give roots a distinct form.The root length is equal to or greater than the crown height.Stage 8:The walls of the root canal are now parallel, and its apical end is still partially open (distal root in molars).Stage 9:The apical end of the root canal is completely closed (distal root in molars).The periodontal membrane has a uniform width around the root and the apex [[Figure 2]].[8]{Figure 3}

These stages of each tooth were converted into scores by using conversion table specified by Chaillet and Demirjian[9] for both girls and boys [[Table 1] and [Table 2]]. Scores of left eight mandibular teeth were summed to obtain a total dental maturity score, which is designated as S. In case of unilateral extraction and radiographic errors, same tooth from the opposite side were taken into consideration [[Figure 4]]. In 2011, Acharya gave the regression formula for both boys and girls. S value was substituted in this formula to get the DA for both girls and boys.[10]{Table 1}{Table 2}{Figure 4}

Males = 27.4351−(0.0097 × S2) ((0.000089 × S3)

Females (23.7288−(0.0088 × S2) ((0.000085 × S3)

where S is the sum of eight left mandibular teeth maturity scores.

Chaillet and Demirjian have given individual scores for girls and boys separately for [Table 1] and [Table 2], respectively.[9]

Statistical analysis

Paired sample tt test was used to find out the difference between individual age groups. Pearson’s correlation was used to find out the overall difference DAdental age and CAchronological age in boys and girls. The obtained data wereas tabulated and analyzed using SPSS version 20.0 (IBM, Armonk, New York, USA).

 Results



Out of 113 patientssubjects, 74 (64.49%) were girls and 39 (34.51%) were boys, at a ratio of 1.89:1. The mean age difference between DA and CA in boys was significant in 8- to 9, 9- to 10, 14- to 15, and 15- to 16 years age groups (PP << 0.05). Whereas in girls, the mean age difference between DA and CA was significant in age groups of 9- to 10, 14- to 15, 15- to 16, and 17- to 18 years. Overall we found a significant correlation between CAchronological age and DAdental age in both girls (rr == 0.84) and boys (rr == 0.882). The overall mean difference between the DA and CA for girls and boys was ++1.14 and ++0.86, respectively. In the whole sample, DAdental age was found to be overestimated by ++1.04 with CAchronological age. Hence, DA and CA for boys and girls showed overestimation of DAdental age ([Table 3])].{Table 3}

The mean CA for boys was 14.47 (3.36) and DA was 15.34 (3.23) with the difference being statistically significant (P == 0.002). The mean CAchronological age for girls was 15.65 (2.76), whereas the mean DA was 16.80 (2.75) and the difference between DA and CA being statistically significant (P == 0.00).

Year-wise differences between the CA and DA [[Table 4]] were calculated. A total of 38.9% of the sample among which 15 were boys (38.4%) and 29 were girls (39.1%) had shown within ±1-year difference between DA and CA. 1 to 2-year difference between DA and CA was noticed in 35.3% of sample of which 16 were boys (41.02%) and 24 were girls (32.4%) with the least percentage of the sample (25.6%), which includes 8 boys (20.05) and 21 girls (28.3%) showing more than 2 years difference between DA and CA [Graph 1].{Table 4}

[INLINE:1]

 Discussion



Identification of a person’s age is one of the most important factors employed in forensic odontology. Estimation of age is required when the birth certificate is not available, and records are suspect for reasons such as medico-legal issues, like children’s below 5 years of age, according to Section 6(a) of Guardianship and Hindu Minority Act 1956, a minor who has not completed the age of 5 years shall ordinarily be in the custody of mother. Under Indian Oaths Amendment Act 1939, the unworn evidence of a child below 12 years of age is admissible if the court thinks he does not understand the nature of on oath. According to Article 24 of the Indian Constitution, a child below the age of 14 years shall not be employed to work in any factory. Under Section 5(iii) of Hindu Marriage Act 1955, the age for marriage for a girl is 18 years.[2],[10],[11],[12],[13],[14],[15]

DA estimation is most commonly used and plays a vital role, as the tooth development shows less variability than other developmental features and also low variability in relation to CA. Developing teeth in radiographs are frequently used to establish the DA.[10],[15]

In the present study, the mean difference between DA and CA for boys is +0.86 years and for girls is +1.14 years. Females were more advanced in DA when compared to males. The overall difference between DA and chronological was +1.04 years. Modified Demirjian’s method overestimated the DA when compared to CA. The study results are similar to Kumar et al., Kiran et al., Tandon et al., and Balla et al. In contrast to our findings, underestimation of age was noted in Mohammed et al.’s study.[11],[12],[13],[14],[15] They found that Demirjian’s modified method underestimated the mean age of males by 0.8 years and females by 0.5 years and also showed that females mature earlier than males in selected population.[12]

Kumar et al. used Demirjian’s 8-teeth method following the French maturity scores and India specific formula. The study group included pretreatment orthodontic radiographs of age range from 7 to 23 years for both males and females and the author found an overestimation of DA for both males and females, which according to him might be due to the inclusion of third molars as it increases the error rates, especially in elder people.[11] Mohammed et al.[12] found that modified Demirjian’s method underestimates the mean age of boys by 0.8 years and girls by 0.5 years, suggesting that girls mature earlier than boys. Kiran et al.[13] found an overestimation of DA for females and males to be 1.91 and 1.72 years, respectively. Tandon et al.[14] observed overestimation of DA for this population.

Balla et al. found in Hyderabad population of 7 to 15 years that DA overestimates the CA. Our results were in accordance with this study.[15] They found that Acharya’s method overestimated age in males and females by 0.18 and 0.47 years, respectively.

Modified Demirjian’s method is subjective in nature, and even a one stage difference may have an impact on DA and to avoid these errors, proper visual discrimination of developmental tooth stages should be improved by training. Moreover, it is equally important to realize no age estimation will accurately determine the exact age of an individual because development naturally varies between individuals. Most important aspect of DA estimation should not restrict to only one method but to apply different methods and carry out repetitive measurements and calculations.

Future prospects

A new formula has to be derived for estimation of age in South Indian population.Comparative analysis of various age estimation methods to determine a most suitable method.Further research is required on a larger sample for all age groups.

 Conclusion



The current study concludes that DA estimation using modified Demirjian’s method following Indian-specific formula in Hyderabad population was found to be overestimated when compared to CA. In the present study, the mean difference between DA and CA for boys is +0.86 years and for girls is +1.14 years. Hence, there is a need for population-specific formulae for each area.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

References

1Saxena S, Sharma P, Gupta N. Experimental studies of forensic odontology to aid in the identification process. J Forensic Dent Sci 2010;2:69-76.
2Bagh T, Chatra L, Shenai P, Veena KM, Rao PK, Prabhu RV et al. Age estimation using Cameriere’s seven teeth method with Indian specific formula in South Indian children. Int J Adv Health Sci 2014;1:2-10.
3Sood R, Mamachand P, Sood R, Parasher P. Role of odontology in determination of identity in forensic science—An overview. J Adv Med Dent Scie Res 2014;2:174-80.
4Kedarisetty SG, Rao GV, Rayapudi N, Korlepara R. Evaluation of skeletal and dental age using third molar calcification, condylar height and length of the mandibular body. J Forensic Dent Sci 2015;7:121-5.
5Priyadarshini C, Puranik MP, Uma SR. Dental age estimation methods: A review. Int J Adv Health Sci 2015;1:19-25.
6Jurca A, Lazra L, Pacurar M, Bica C, Chibelen M., Bud E. Dental age assessment using Demirjian’s method—A panoramic study. Eur Sci J 2014;10:51-9.
7Demirjians A, Goldstein H, Tanner JM. A new system of dental age assessment. Hum Biol 1973;45:211-27.
8Bijjaragi SC, Sangle VA, Saraswathi FK, Patil VS, Ashwini Rani SR, Bapure SK. Age estimation by modified Demirjian’s method(2004) and its applicability in Tibetan young adults: A digital panoramic study. J Oral Maxillofac Pathol 2015;19:100-5.
9Chaillet N, Demirjian A. Dental maturity in South France: A comparison between Demirjian’s method and polynomial functions. J Forensic Sci 2004;49:1059-66.
10Acharya AB. Age estimation in Indians using Demirjian’s 8-teeth method. J Forensic Sci 2011;56:124-7.
11Kumar VJ, Gopal KS. Reliability of age estimation using Demirjian’s 8 teeth method and India specific formula. J Forensic Dent Sci 2011;3:19-22.
12Mohammed RB, Koganti R, Kalyan SV, Tircouveluri S, Singh JR, Srinivasulu E. Digital radiographic evaluation of mandibular third molar for age estimation in young adults and adolescents of South Indian population using modified Demirjian’s method. J Forensic Dent Sci 2014;6:191-6.
13Kiran CS, Reddy RS, Ramesh T, Madhavi NS, Ramya K. Radiographic evaluation of dental age using Demirjian’s eight-teeth method and its comparison with Indian formulas in South Indian population. J Forensic Dent Sci 2015;7:44-8.
14Tandon A, Agarwal V, Arora V. Reliability of India-specific regression formula for age estimation of population in and around Bahadurgarh, Haryana (India). J Oral Biol Craniofac Res 2015;5:193-7.
15Balla SB, Venkat Baghirath P, Hari Vinay B, Vijay Kumar J, Babu DB. Accuracy of methods of age estimation in predicting dental age of preadolescents in South Indian children. J Forensic Leg Med 2016;43:21-5.