COMPARISON OF VARIOUS DENTAL AGE ESTIMATION METHODS IN TEENAGERS AND ADULTS

INTRODUCTION

Forensic Odontology is an applied discipline of Odontology. It is also known as Forensic Dentistry. It helps in relating the dental evidence found at the crime scene to the examination.

The application of dentistry helps in the criminal investigation by using the principles of dentistry and the knowledge of expertise in this field. It provides service for the community related to criminal and civil jurisdictions. The role of forensic odontologists is important when it comes to the investigation at the crime scenes in death cases. It is also beneficial in clinical forensic medicine in cases like child abuse, sexual assault, domestic violence etc.

The dental evidence is used to find the age of a person using different methods and it also helps in identification of a person, as every individual has a difference in teeth structure and alignment. The identification of a dead person can also be done using dental records or ante- mortem photographs. A forensic dentist requires the knowledge of various disciplines so that they can use the knowledge and can link it with the given evidences, obtained dental records that help in identifying an individual and other information required by the authorities to establish the identity of a person in a particular case.

The diverse fields in dentistry and therapeutic sciences require an intense age information to gauge the correct planning for the treatment technique in endocrinology, pediatric dentistry and orthodontics. In legal science, it is imperative in issues identified with the assent or criminal capacity emerge, or in the identification of expired people. The primary criteria for Odontological examination are tooth emission and tooth mineralization, both formative and natural highlights. Tooth mineralization is assessed by utilizing an orthopantomogram, a radiograph of the entire dentition. Different phases of characterization have been advanced for the assessment procedure. The most widely recognized strategy utilized is the examination between various populaces that were first given by Demirjian on the year 1973.

Development of the deciduous teeth starts in the uterus at around 4 months and changeless teeth finish arrangement at roughly 25 years old. It is less influenced by natural components. Rai discovered that the dental development is more dependable in youngsters to locate the organic development. Ordered age is synchronous with dental age of a typical youngster. The treatment arranging and the anticipation of certain orthodontic critical marker is used to decide the irregular ejection succession with the goal that preventive measures can be executed. Dental age can be comprehensively ordered in the premise of procedure utilized for the assurance of age.  We can use Visual, Radiographic, Chemical, and Histological visual techniques to calculate the dental age.

DENTAL AGE ESTIMATION IN TEENAGERS AND ADULT

Dental age estimation in teenagers and adult people depends on the period of development of the tooth in the oral pit and the tooth calcification. The radiographic strategy is utilized as a part of estimating dentition age. The radiographic investigation of developing dentition will aid in age determination, particularly when there’s no clinical prove accessible (2.5-6yr). Numerous investigations have inferred that the tooth arrangement is a more solid pointer of dental development than gingival rise or ejection.

1.    Nolla’s Technique

Nolla devised a system of dental age assessment using radiological appearances of maxillary teeth and mandibular teeth. Nolla devised a method of age estimation by evaluating the Calcification of the permanent dentition. The Calcification of permanent dentition was divided into 10 stages such as 1) Absence of crypt. 2) Presence of Crypt. 3) Initial Calcification. 4) 1/3rd Crown completed. 5) 2/3rd crown completed. 6) Crown almost completed. 7) Crown completed 8)1/3rd root completed. 9) 2/3rds of Root Completed. 10) Root almost Completed – open apex. 11) Apical end of root completed for each group of teeth like incisors, canine, premolars and molars of maxillary and mandibular arches separately. The radiograph of the individual was matched with a comparative figure given by Nolla. Each tooth was recorded with a reading and a sum total is made for maxillary and mandibular teeth. Later the sum total is compared with table given by Nolla. Separate table was given for boys and girls and including or excluding third molars.

2.    Demirjian’s Method

Demirjian, Goldstein, and Tanner strategy: In 1973, Demirjian presented a technique which assessed chronological age in view of advancements of seven teeth from the left half of the mandible. Demirjian, Goldstein, and Tanner utilized these stages by observing the tooth shapes, from the earliest starting point of calcification through to last develop frame. This was later adjusted by Demirjian and Goldstein in 1976. In this strategy, the 7 remaining lasting mandibular teeth were investigated and every tooth’s improvement was partitioned into eight formative stages. The framework most generally acknowledged just like the most precise is the one created by Demirjian, which surveys the creating dentition of an individual kid. The development phases of the left mandibular teeth (barring the third molars) are surveyed, the individual scores for every one of the seven phases are summed and this showed the solitary dental age which expressed the chronological age of an offspring. Koshy & Tandon (1998), Prabhakar, et al, (2002) found a poor connection when Demirjian’s strategy was utilized for various populaces.

3.    Schour and Masseler Method

In 1941, Schour and Masseler considered the improvement of deciduous and perpetual teeth, portraying 21 ordered strides from 4 months to 21 years old and distributed the numerical advancement outlines for them. This method doesn’t isolate reviews for males and females. The outline depends on histological areas which consider 3 attributes-

• Teeth that have ejected
• Measure of resorption of underlying foundations of essential teeth
• Measure of improvement of perpetual teeth.

4.    Moorees, Fanning and Chase Method

It Provides norms of the formation of ten permanent teeth, namely, the maxillary incisors and all eight mandibular teeth on the basis of fourteen arbitrarily selected stages of tooth development. Lasting teeth and the mean age for the relating stage were resolved using the Intraoral Periapical X-ray of mandibular canines.

5.    Cameriere’s Method

In this technique, the dental age is ascertained in view of the connection between the age and estimation of open apices of teeth. The seven remaining perpetual mandibular teeth are utilized to figure the dental age. The number of teeth with finished root improvement and shut apical closures are noted as N0. In the teeth with fragmented root advancement, the separation between inward sides of the open peak is estimated (A). For the teeth with two roots, the aggregate of the separations between inward sides of two open apices is taken. To invalidate the amplification, the estimation of open zenith or apices is separated by the tooth length (L) for every tooth and these standardized estimations of seven teeth are utilized for age estimation. The dental development is figured as the entirety of standardized open apices (s) and the quantities of teeth with root improvement (N0). The qualities are substituted in the accompanying relapse equation for age estimation.

Age = 8.971 + 0.375 g + 1.631 × 5 + 0.674 N0 – 1.034 s – 0.176 S. N0

where g is a variable equivalent to 1 for young men and 0 for young ladies

Numerous creators have observed Cameriere’s technique with modifications to be the most precise strategy for age estimation. In any case, a relapse display for various populaces is required for exact estimation.

6.    Haavikko’s Method

This technique was presented by Haavikko (1974) using the cross-sectional information from radiographs of 1162 kids between the ages of 2 and 21 years. Twelve radiographic phases of 4 permanent teeth are utilized to evaluate the dental age. This strategy is valuable when a portion of the perpetual teeth might miss innately. In this strategy, the development of the teeth is evaluated – six identifying with crown arrangement and six identifying with root arrangement. At that point normal is then taken to decide the dental age.

7. Gustafson’s method

 This method is used to estimate the age from physiological changes of teeth. This method studied different physiological changes that occurs in teeth. The estimation of changes is based on the evaluation of ground sections of teeth. These are six in numbers- attrition, periodontosis, root translucency, cementum opposition, secondary dentin deposition, root resorption.

1. Attrition- it occurs due to wear and tear from mastication. Mostly upper surface of teeth gets destroyed.
2. Paradentosis- It occurs due to the poor hygiene. Regression of gums take place due to which necks and roots of teeth get exposed and leads to teeth loosening.
3. Secondary Dentin- it develops in the pulp cavity. It decreases the size of the cavity. Aging is the main reason and pathological conditions also like caries.
4. Cementum Apposition- Thickness near the end of the root occurs. It deposited slowly throughout the life.
5. Root resorption- It involves both cementum and dentin which show characteristically sharp grooves.
6. Transparency of the root- Canals in the dentin are at first wide, with age they are filled by mineral, so that they become invisible and the dentine becomes transparent.

We scored these changes from 0 to 3 range. 0 – no change, 1 – beginning of change, 2 – obvious change, 3 – maximum change

8.    Willem’s Method

Willems method measures the developmental stages of the seven left permanent mandibular teeth and is frequently used for dental age estimation. Willem’s method is the revised version of Demirjian method, based on modified dental maturity scores to estimate age of children in years for both the sexes.

REVIEW OF LITERATURE

Rai B & S.C (2006) conducted a study regarding the development of tooth using radiographs and estimating the accuracy of age. Tooth formation helps in age prediction and maturity assessment. Development of tooth shows less variability than other features of development. The methods author used in this paper are Demirjian, Nolla, Haavikko, Willem and Cameriere methods. She used panoramic radiographs and did cross section study of them. Dental age of each method was compared with the chronological age. According to this study the method of Willems shows the most accurate results than the other methods. The mean age was overestimated as 0.25 years for boys and 0.24 for girls. The variance between estimated dental age and chronological age for both boys and girls were substantial from zero. Whereas Haavikko shows mean estimation of 0.04 years for boys and 0.03 for girls, accuracy was significantly different. Cameriere shows mean estimation of 0.05 years for boys and 0.04 years for girls and accuracy was significantly different. Same goes with Nolla and Demirjian method, both shows different accuracy. Therefore, Willem’s method is more accurate compare to other methods.

Patnana, et al., (2014) conducted a study in which they evaluate the dental age is important for treatment planning in the specialties of pedodontics and orthodontics. Although, Demirjian’s technique was considered average for dental age estimation, it may not be reliable for all population. The study was done in Visakhapatnam (Andhra Pradesh, India) on 102 children belonging to age group 6 to 14 years old by taking OPGs.  They used different age estimation formula- Demirjian’s, Haavikko’s and Willem’s method. The reliability of these methods was concluded through this study. Dental age was calculated using, Haavikko’s, Demirjian’s and Willem’s methods and comparison was done using chronologic age for each subject. In the dental age a significant overestimation by Demirjian’s method was concluded with a 0.55-year mean difference and Haavikko’s showed the underestimation band and Willems methods with a mean difference of 1.95 and 0.20 year respectively when compared with chronologic age. The mean difference between chronologic age and dental age was not significant in William’s method which shows a close relation between dental and chronologic ages. In Visakhapatnam children, Willem’s method shows the more accurate result than Haavikko’s and Demirjian’s methods.

Javadinejad  (2015)did a study by comparing the different methods of age estimation based on the OPGs of developing teeth. In medical and legal procedures, determination of age is an important concern. Development of teeth is used in age determination and state of maturity. In forensic science dental age estimation is an important aspect. As teeth undergo various development stages in the first 25 years of a human’s life. The aim of this study was to relate the accuracy of four radiographic age estimation methods. These methods are Demirjian’s method, Willem’s method, Cameriere’s method and Smith method.  For this study 537 radiographs were taken of healthy children (age: 3.9 to 14.5 years). The radiographs were evaluated to find the differences and correlation between chronological and dental ages and were assessed by paired t-test and Pearson’s correlation analysis respectively. The result shows that mean chronological age was 8 .93+- 2.04 years. Age was overestimated by Demirjian’s method (0.87+- 1.00 years), Willem’s method (0.36+- 0.87 years) and Smith’s method (0.06+- 0.63 years). Whereas, Cameriere’s method underestimate the age by 0.19+- 0.86 years. While paired t-tests revealed significant differences between the mean chronological age and ages determined by Demirjian’s, Willem’s, and Cameriere’s methods (P < 0.001), such a significant difference was absent between chronological age and dental age based on Smith’s method (P = 0.079). Pearson’s correlation analysis suggested linear correlations between chronological age and dental age determined by all four methods. Hence according to this study, it was concluded that Smith’s method shows the highest accuracy among all these methods.

Priyadarshini, et al., (2015) reviewed some dental age estimation methods by studying different methods. Age is a crucial factor playing significant role in every part of life.  Identification of a person is an important characteristic of forensic dentistry and medicine. Race, age and gender is used for personal identification. Registered birth date is used as a chronological age. In clinical practice, age is considered as an essential factor. Also, in research and court of law. Estimation is done on the basis of dental age, bone age and chronological age and other factors. A vital factor shows less variability that is a dental age because it shows less changes than the other features of the development. Hence, dental age is considered to be vital in establishing the age of an individual. Various aspects of estimation age like biochemical, radiological and morphological methods are reviewed under this paper.

Kotecha D (2016) reviewed the study on age estimation in children through dental records. Age estimation is required in governing justice to a person jumbled in criminal and civil cases. There are different methods used for age estimation and these are visual, radiographic, chemical and histological. Dental age estimation in children and adolescents can be done using different methods i.e Schour and Masseler method, Nolla’s method, Moorees, Fanning and Hunt method, Demirjian, Goldstein and Tanner method and many more. This paper concluded that the growth of an individual is influenced by race, genetics, hormonal influence, climatic conditions, eating habit etc. using digital radiography the calcification can be determined precisely. Racial differences can be seen. Further studies are required for age estimation based on age, ethnicity to check the validity and reliability of the application.

DISCUSSION

According to many studies Willem’s method showed the better accuracy to overemphasize the dental age both in females and males but the results vary in every study. Few authors found that Demirjian’s method was precise on the popluation that was studied using Demirjian’s method. But in few studies they highlighted numerous limitations of this method. Willem’s method has its own limitation as it depends on the variation of population.

The role of radiology is important in determining the human age as radiological pictures are routinley operated in the method. Since 1982, the use of radiographs has been active as dental pratice in utilizing the estimation of age. This method is simple and  includes the identification of mineralized stages on radiographic images which then are compared with the standard stage to estimate the approximate range of age.

In many studies, the accuracy of Demirjian’s method is investigated as it was done on different populations to check the reliability of this method. As compared to Cameriere’s method, Smith method, Schour and Masseler method, Nolla’s method, Moorees, Fanning and Hunt method, Demirjian’s method showed the better accuracy in dental age estimation when compared to the chronological age.

CONCLUSION

Determination of dental age is an important aspect in forensic science; sometimes at scene of crime we just get bite marks or in case of mass disasters if we get only teeth samples as it won’t degrade easily. In those cases this method will help to find out the age, sex, further information and to eliminate the non- human remains.

This review paper concluded that Willem’s method and Demirjian’s method showed the accurate result in estimating the dental age. Further studies are required for age estimation based on age, ethnicity to check the validity and reliability of the application. The study should be conducted on a large scale which will help in getting better results and accuracy.  These methods should be used on different population and various ethnic groups also so, for further knowing the changes we need to perform it on large number of population and it should be compared with the other studies.

REFERENCES

1. Alastair, J. (n.d.). Forensic Odontology: An Essential Guide (1 ed.). John Wiley & Sons, Ltd; Development of the dentition.
2. Ardakani, F. B. (2007). The accuracy of dental panoramic radiography as an indicator of chronological age in Iranian individuals. J Forensic Odontostomatol, 25(2), 30-35.
3. Baghadi, Z. &. (2012, March). Accuracy of population-specific Demirjian curves in the estimation of dental age of Saudi children. Int J Paediatr Dent, 22(2), 125-131.
4. Bagherpour, A. I. (2010, April). Dental age assessment among Iranian children aged 6-13 years using the Demirjian method. Forensic Sci Int, 197(1-3), 121.
5. Cugati, N. K. (2015). Dental age estimation of growing children by measurment of open apices: A Malaysian formula. J Forensic Dent Sci, 7(3), 227-231.
6. Demirjian, A. &. (1976). New systems for dental maturity based on seven and four teeth. . Ann Hum Biol, 3, 411–421.
7. Demirjian, A. G. (1973). A new system of dental age assessment. Hum Biol,, 45, 221-7.
8. Emilia, A. A. (2011). Dental Maturity: A biologic Indicator of chronological age : Digital radiographic study to asses dental age in Roman children. Int J bio biomed Eng, 5, 32-40.
9. Haavikko, K. (1974). Tooth formation age estimated on a few selected teeth- a simple method for clinical use. Proc Finn Dent Soc, 70(1), 15-19.
10. Javadinejad, S. S. (2015, February 20). A Comparison of the Accuracy of Four Age Estimation Methods Based on Panoramic Radiography of Developing Teeth. Dental Research, Dental Clinics, Dental Prospects.
11. Kohler, s., Schmelzle, R., & Puschel , K. (1994). Die Entwicklung des weisheitszalmesals. Adv Med Dent Sci, 2(3), 53-55.
12. Koshy, S. &. (1998). Dental age assessment: The applicability of Demirjian’s Method in south Indian children. Forensic Sci Int, 94, 73-85.
13. Kotecha, D. (2016, November). Dental Age Estimation in Children: A Review. Forensic Research & Criminology International Journal,, 3(1).
14. Kullman, L. J. (1992). Root development of the lower third molar and its relation to chronological age. Swed Dent J, 16:161-7.
15. Moorees, C. F. (1963). Age estimation of formation stages for ten permanent teeth. J Dent Res, 42, 1490-1502.
16. Nik-Hussein, N. K. (2011, January). Validity of Demirjian and Willems methods for dental age estimation for Malaisian children aged 5-15 years old. Forensic Sci Int,, 204(1-3), 208.
17. Nolla, C. M. (1960). The development of permanent teeth. J Dent Child, 253-266.
18. Pandey, M. H. (2012, April-September). Dental age assessment of 7-15 years old children of Rajasthan using Demirjian’s method. Indian journal of dental research review.
19. Patnama, v. &. (2014, September- December). Evaluating the Reliability of Three Different Dental Age Estimation methods in Visakhapatnam children. . Int J Clin Pediatr Dent,, 7(3), 186-191.
20. Prabhakar, A. R. (2002). Applicability of Demirjian’s Method of age assessment in Children of Davangere. J Indian SocPedoPrev Dent, 20(2), 54-62.
21. Priyadarshini, C. M. (2015, April). Dental Age Estimation Methods: A Review. . International journal of advanced health sciences, 1(12).
22. Rai, B. &. (2006). Tooth developments: An accuracy of age estimation of radiographic methods. World Journal of Medical Sciences, 1(2), 130-132.
23. Rai, B. K. (2010). Age Estimation in children by measurement of open apices in teeth: An Indian Formula . Int J Legal Med, 124(3), 237-241.
24. Schour, I. &. (1940). Studies in tooth development: The growth pattern of human teeth. . J Am Dent Assoc, 27(11), 1778-1793.
25. voor, A. W. (1973). Can dental development be used for assessing age in underdeveloped communities? J Trop Pediatr Environ Child Health, 19, 242.
26. Willems, G. M.-R. (2002). Non-destructive dental-age calculation methods in adults: Intra and inter observer effects. Forensic Sci Int, 126, 221-6.
27. Willems, G. V. (2001). Dental Age Estimation in Belgian children: Demirjian’s technique revistited. . J Forensic Sci, 46(5), 893-895.