Comparison of two methods in estimating the relation between dental age and chronological age

(1)

COMPARISON OF TWO METHODS IN ESTIMATING THE RELATION

BETWEEN DENTAL AGE AND CHRONOLOGICAL AGE

A Dissertation submitted in

partial fulfillment of the requirements

for the degree of

MASTER OF DENTAL SURGERY

BRANCH – IX

ORAL MEDICINE AND RADIOLOGY

THE TAMILNADU Dr.M.G.R.MEDICAL UNIVERSITY

(2)

DECLARATION

TITLE OF DISSERTATION

COMPARISON OF TWO METHODS

IN ESTIMATING THE RELATION

BETWEEN DENTAL AGE AND

CHRONOLOGICAL AGE

PLACE OF STUDY

K.S.R .Institute of Dental Science and

Research

DURATIONOF COURSE

3 Years

NAME OF THE GUIDE

Dr.Nazargi Mahabob

HEAD OF THE DEPARTMENT

Dr.(Capt) S.Elangovan

I hereby declare that no part of the dissertation will be utilized for gaining

financial assistance for research or other promotions without obtaining prior

permission of the Principal, K.S.R. Institute of Dental Science and Research,

Tiruchengode. In addition, I declare that no part of this work will be published

either in print or electric without the guide who has been actively involved in the

dissertation. The author has the right to reserve publishing of work solely with

prior permission of the Principal, K.S.R. Institute of Dental Science and Research,

Tiruchengode.

(3)

CERTIFICATE BY THE GUIDE

This is to certify that dissertation titled

“COMPARISON OF TWO

METHODS IN ESTIMATING THE RELATION BETWEEN DENTAL AGE

AND CHRONOLOGICAL AGE”

is a bonafide research workdone by

Dr.G.SURYA

in partial fulfillment of the requirements for the degree of

MASTER OF DENTAL SURGERY

in the speciality of

ORAL MEDICINE

AND RADIOLOGY.

Date :

Place :

Signature of H.O.D Signature of Guide

DR.(CAPT).S.ELANGOVAN.,M.D.S. DR.NAZARGI MAHABOB.,M.D.S.

(4)

ENDORSEMENT BY THE H.O.D,PRINCIPAL/HEAD OF THE

INSTITUTION

This is to certify that

Dr.G.SURYA

, Post Graduate student (2015-2018) in the

Department of Oral Medicine and Radiology, K.S.R Institute of Dental Science

and Research, has done this dissertation titled

“COMPARISON OF TWO

METHODS IN ESTIMATING THE RELATION BETWEEN DENTAL AGE

AND CHRONOLOGICAL AGE”

under our guidance and supervision in partial

fulfillment of the regulations laid down by the

Tamilnadu Dr.M.G.R.Medical

University

,Chennai-600032 for

M.D.S.,

(Branch-IX)

Oral Medicine and

Radiology

degree examination.

Seal & Signature of H.O.D Seal & Signature of Principal

DR.(CAPT).S.ELANGOVAN.,M.D.S Dr.G.S.KUMAR.,M.D.S.

(5)

ACKNOWLEDGEMENT

I am extremely grateful to my guide, Dr. Nazargi Mehabob M.D.S, Reader ,

Department of Oral Medicine and Radiology , KSR Institute of Dental Sciences and

Research, Tiruchengode for inspiring me to choose this topic. His meticulous guidance,

encouragement and eye for perfection, made my work easier and complete. His unending

belief in me was the key element which helped me to bring out the best in me.

I would most humbly like to thank my Head of the Department, Dr. (Capt)

S.Elangovan M.D.S., Professor , Department of Oral Medicine and Radiology , KSR

Institute of Dental Sciences and Research, Tiruchengode whose invaluable guidance have

instilled the confidence and determination in me to strive for my perfection.

I take this opportunity to express my humble gratitude to Dr.G.S.Kumar,

Principal, K.S.R. Institute of Dental Science and Research for his permission and

encouragement.

I want to express my deepest thanks to Dr.Suman M.D.S., Professor , Department

of Oral Medicine and Radiology , KSR Institute of Dental Sciences and Research, for her

tremendous help and guidance. Her constant supervision, motivation and support enabled me

to successfully complete my dissertation and realizing my goal in time. Her words can always

inspire me and bring me to a higher level of thinking.

(6)

It is my pleasure to express my deep thankfulness to Dr. Senthil Kumar M.D.S.,

Reader, Department of Department of Oral Medicine and Radiology , KSR Institute of

Dental Sciences and Research, for his motivation, encouragement and valuable advice at

times in need during the course of my work.

I thank Dr. Deepika Rajendran M.D.S., Senior Lecturer and Dr. Gomathi

M.D.S., Senior Lecturer,Department of Oral Medicine and Radiology , KSR Institute of

Dental Sciences and Research, for her support and encouragement.

Words are nothing but a medium to express my profound thanks to Dr.Sharmila

Shanmuganathan for their untiring stint of moral support, encouragement , and help.

My heartfelt appreciation to all my dear seniors, my juniors and colleagues for

their support during the period of my work.

I am thankful to Dr.Prakash M.D.S., Department of Community Dentistry,K.S.R.

Institute of Dental Science and Research,for the Biostatistics work.

I feel so blessed to have such a wonderful family and who make it a point to

remind me that I’m special to them. I owe a lot to my parents, my sister who encouraged

and helped me at every stage of my personal and academic life, and longed to see this

(7)

Dental Intra Oral Xray Film

41

4

Dentsply Rinn Holder

41

5

Automatic Processor

42

6

Armamentarium for Tracing Radiograph

42

7

Tooth Length

43

8

Pulp Length

43

9

Root Length

44

(9)

LIST OF TABLES

S.NO TITLE PAGE NO

1 DESCRIPTIONS OF STAGES OF TOOTH DEVELOPMENT OF

DEMIRJIAN ET AL., METHOD

36

2 DEVELOPMENTAL STATUS OF A PARTICULAR TOOTH BY

WILLEMS ET AL.,METHOD

38

3 DISTRIBUTION OF THE SUBJECTS BY THEIR AGE AND

GENDER

48

4 ILLUSTRATING THE RESULTS OBTAINED FROM KVAAL’S

METHOD (GROUP 1)

49

METHOD (GROUP 2)

50

METHOD (GROUP 3)

51

METHOD (GROUP 4)

(10)

METHOD (GROUP 5)

53

9

DEVELOPMENTAL STAGES OF EACH OF THE RIGHT

MANDIBULAR TEETH FOR GROUP I

54

10

DEVELOPMENTAL STAGES OF EACH OF THE

RIGHT MANDIBULAR TEETH FOR GROUP II

55

11

MANDIBULAR TEETH FOR GROUP III

56

12

MANDIBULAR TEETH FOR GROUP IV

57

13

MANDIBULAR TEETH FOR GROUP V

58

14

ILLUSTRATING THE RESULTS OBTAINED FROM WILLEM’S METHOD (GROUP 1)

59

15 ILLUSTRATING THE RESULTS OBTAINED FROM WILLEM’S METHOD (GROUP 2)

(11)

16

61

17

62

18

63

19

MEAN AND SD OF DIFFERENT AGE ESTIMATION

METHODS OF DIFFERENT AGE GROUPS

64

20

DESCRIPTIVE STATISTICS OF TWO AGE ESTIMATION

METHODS

65

21

CONFIDENCE INTERVAL FOR DIFFERENT AGE

ESTIMATION METHODS

66

22

MEAN AGE OF DIFFERENT AGE ESTIMATION METHODS

BY GENDER

67

23

MEAN DIFFERENCES AND STANDARD ERROR

DIFFERENCES OF DIFFERENT AGE ESTIMATION METHODS

(12)

(13)

CHARTS

S.NO

TITLE

PAGE NO.

1

Distribution of the subjects by their age and

gender

69

2

Mean chronological age of different age groups

69

3

Mean estimated dental age of different age

groups by Willem’s method

70

4

groups by Kvaal’s method

70

5

groups by different age estimation methods

71

6

Mean age of males by different age estimation

methods

72

7

Mean age of males by different age estimation

methods

(14)

(15)

INTRODUCTION

Page 1

Personal identification is becoming increasingly important not only in legal medicine

but also in criminal investigation, identification and Genetic Research.1It is an important

basis for differentiating guilty from innocent in legal issues, for ethical issues and for

declaration of death reports and the basis for probing into criminal cases, mass disaster or

war victims.2

The mouth has been identified as the organ system “where it all begins.” Forensic

odontology, or forensic dentistry, was defined by Keiser- Neilson in 1970 as “a branch of

forensic medicine which in the interest of justice deals with the proper handling and

examination of dental evidence and with the proper evaluation and presentation of the dental

findings.”3

Dr. Oscar Amoedo was considered as the father of the forensic odontologist. The thesis

done by him entitled ‘L’ Art Dentaire en Medicine Leagale’ to the faculty of medicine earned

him a doctorate. This book is the first comprehensive text on forensic odontologist.4

The traditional methods of personal identification include anthropometry, finger prints,

sex determination, estimation of age, measurement of height, identification of a specific

individual, and differentiation by blood groups.5 The accurate estimation of age at the time of

death with the help of dental remains is an important parameter for identification. 2

Age plays an important role in various fields such as forensic science, various social

and legal settings and treatment planning in clinical dentistry.6 The age of a person can be

(16)

INTRODUCTION

Page 2

In 1889, Laccasagne was the first to use changes in the teeth of adults to estimate

age.8 Later, Bodecker, in 1925, pointed out that some morphological changes in teeth could

be related to increasing age.9

Literature reports different morphological and radiological techniques for age

assessment. Dental age estimation has gained acceptance because it is less variable when

compared to other skeletal and sexual maturity indicators.10 Examination of teeth in many

ways form a unique part of human body, as they are the most durable and resilient part of the

skeleton.11At times teeth are the only means of identification when the dead bodies have

under gone changes so extensive, that external characteristics yield little information.12

Adult teeth consists of enamel as the outermost covering of tooth crown and dentin

underneath, both of which are hard tissues resistant to decomposition, followed by pulp as

the innermost soft tissue core. Likewise cementum is the outermost covering for the surface

of root which is also resistant to decomposition. 2

Dental age (DA) determination is important because it is a useful tool to estimate the

CA of a child with an unknown birth date. Teeth are among the most reliable tools in the

process of identification of age, especially in the first and second decades. The stages of

development can be considered as one of the most dependable indicators in assessing the age

(17)

INTRODUCTION

Page 3

Dental Age Estimation Methods 14

Various methods are utilized for determination of age from dentition. Dental age assessment

methods may be classified as:

A. According to the state of development of the dentition:

Methods applied to the forming dentition

Methods for the adult fully formed dentition.

B. According to the technique of investigation:

Clinical or visual

Radiographic

Histological

Physical and chemical analysis

i. Clinical or visual method: Visual observation of the stage of eruption of the teeth and

evidence of changes due to function such as attrition can give an approximate estimate of

age.

ii. Radiographic method: Radiography can provide the gross stage of dental development of

(18)

INTRODUCTION

Page 4

iii. Histological method: Histological methods require the preparation of the tissues for

detailed microscopic examination, which can determine more accurately the stage of

development of the dentition. This technique is more appropriate for postmortem situations.

It is also significant in estimation of age of early development of dentition.

iv. Physical and chemical analysis: The physical and chemical analysis of dental hard

tissues to determine alterations in ion levels with age have been proposed. While these

techniques, as yet, are not of great value to the forensic odontologist, future developments

might provide an adjunctive means of collecting evidence of value in the dental context.

Age estimation using the dentition can be grouped into 3 phases(15-21)

1. Age estimation in prenatal, neonatal and early postnatal child

2. Age estimation in children and adolescents

(19)

INTRODUCTION

Page 5

1. Age estimation in prenatal, neonatal and early postnatal child

- Age assessment from the neonatal line

- Age assessment based on thickness of enamel and dentin from the neonatal line

-Age assessment from the incremental lines

-Age assessment from the weight of the development dentition

2. Age estimation of children and adolescents

-Age estimation using charts prepared from population surveys

-Age assessment by examination of the incremental pattern of tooth formation

-Third molars in age estimation

3. Estimation of age in adults

-Gustafson’s method

-Age estimation using color of the teeth

-Age estimation using fluorescence from dentine and cementum

-Age estimation in dental pulp DNA based on human telomere shortening

(20)

(21)

AIMS AND OBJECTIVES

Page 7

 To determine dental age by radiographic methods in Digital Orthopantamograph using Willem’s method and in Intra oral periapical radiograph using Kwaal’s method

(22)

(23)

REVIEW OF LITERATURE

Page 9

Sigrid I.Kvaal et al (1995) 22_{conducted study using 100 periapical radiographs which were}

taken using paralleling technique and the samples were collected from clinics of dental

faculty in Oslo. The age ranging from 20-87 years were included in the study. Tooth / root

length, the pulp /root length, as well as the pulp/root width at three levels were calculated

from the radiographs of maxillary central and lateral incisors and second premolars, and

mandibular lateral incisors, canines and from first premolars by using Vernier calipers. All

five ratios had significant influence on age except the ratio between length of tooth and root.

The coefficient of determination (r2_{) for the regression was strongest when the ratios from all}

six types of teeth from both jaws were employed.

Andrea G.Drusini et al (1997) 23_{examined panoramic radiographs of 425 premolars and}

421 molars to measure the coronal height and the height of coronal pulp cavity and 100 teeth

from 100 year old skeletons. For panoramic study,213 males and 220 females of known age

ranging from 9-76 years were included. Correlations were slightly higher in males than

females with an error of +5 years in 81.4% of cases. In historical sample, error of +5 years in

70.37% of cases of molars. It was found that this method can be applied to estimate the age

in both living individuals and skeletal material of unknown age.

Kolltveit and Solheim et al.(1998) 24 had conducted a study to compare the reliability of

manual measurements (vernier calipers using a stereomicroscope) with that of

(24)

REVIEW OF LITERATURE

Page 10

dental radiographs. Ratios calculated from the linear measurements of “tooth” by “pulp”

showed a weaker correlation with age when the image analysis program was employed than

did ratios based on conventional measurements (without image analysis) of the same. The

main source of errors in measurement seemed to be difficulties in recognition of the

reference points on the radiographs when viewed on the monitor, and therefore in defining

the line to be measured.

Sema Kedici P et al (2000) 25 obtained 20 measurements of different variables in incisor

teeth using a SEM micrometric scaler and the results were statistically correlated with age by

the multiple regression method. A formula was then derived from the calculations for age

estimation which gave statistically acceptable results. Gender differences were also

investigated and when separated delivered even stronger correlation.

Willems et al (2001)26 conducted a study was to evaluate the accuracy of Demirjian’s

dental age estimation in children in a Belgian Caucasian population and to adapt the scoring

system in case of a significant overestimation as frequently reported.2523

orthopantomograms of 1265 boys and 1258 girls, of which 2116 (1029 boys and 1087 girls)

were used for estimating the dental age with the Demirjian’s technique. The 407 other

orthopantomogram were beyond the original age limit. A second sample of 355

orthopantomograms was used to evaluate the accuracy of the original method and the

(25)

REVIEW OF LITERATURE

Page 11

between the obtained dental age and the chronological age. A weighted ANOVA was

performed in order to adapt the scoring system for this Belgian population. The

overestimation of the chronological age was confirmed. The adapted scoring system resulted

in new age scores expressed in years and in a higher accuracy compared to the original

method in Belgian Caucasians.

Martin-de las Heras et al (2002) 27 and coworkers, who have proposed the use of

spectroradiometry as an objective method for dentine color measurements for estimation of

age. 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

(26)

REVIEW OF LITERATURE

Page 12

Tomoya Takasaki et al (2003) 28 _{conducted a study for the estimation of age based on}

evidence found in teeth has received considerable attention within the field of forensic

science. They determined the terminal restriction fragment (TRF) length, as telomere length,

to estimate age. Using dental pulp DNA they found that the average TRF length showed a

tendency to shortening with aging. Their findings show that telomere shortening, based on

dental pulp DNA is a new and useful approach to estimate age of the subject at the time of

death.

Vandevoort F.M et al (2004) 29correlated the dental age with an individual’s chronological

age based on the calculated volume ratio of pulp versus tooth volume measured. An X-ray

micro focus computed tomography unit (μCT) with 25μm spatial resolution was used to

non-destructively scan 43 extracted single root teeth of 25 individuals with well-known

chronological age. Custom-made analysis software was used by two examiners to obtain

numerical values for pulpal and tooth volume. The ratio of both was calculated and

statistically processed. No significant intra- or inter-examiner differences were found.

Wittwer-Backofen et al (2004) 30 conducted a study using tooth cementum annulations

(TCA) technique for estimating a subject’s age from cementum annulations. Indicators like

sex differences, intra individual correlations, and the effects of periodontal disease did not

have a quantitative effect on the number of TCA bands. A major disadvantage of the above

methods of estimating age in adults is the necessity to extract and/or section the teeth. While

(27)

REVIEW OF LITERATURE

Page 13

Paewinsky et al (2005) 31_{analysed panoramic radiographs of 168 patients aged between 14}

to 81 years. Pulp/root length, pulp/tooth length and pulp/root width at three different root

levels were calculated in one of mandibular lateral incisors, canines and first premolars and

maxillary central and lateral incisors and second premolars. The width ratios of the pulp

cavity showed significant correlation to the chronological age and the coefficient of

determination(r2_{) was highest in the upper lateral incisors}

Nathalie Bosmans et al (2005) 32 applied Kvaal’s dental age calculation technique on one

hundred and ninety panoramic dental radiographs with the age group ranged from 19 to 75

years. There was no significant difference between long cone periapical technique and

orthopantomographs when all six teeth were selected to predict the age.

Roberto Cameriere et al (2006) 33_{in a study to estimate the age from 33 skeletal remains by}

using radiograph of canines. This method showed great reliability to estimate the age of old

subjects who died over 50 years.

Balwant Rai et al (2006)34 examined panoramic radiographs of 75 healthy children (40 boys

and 35 girls) aged between 5-14 years. Demirjian, Nolla, Haavikko, Williams and Cameriere

methods were applied for estimation of age. The result of our study have shown that

Williams method is more accurate followed by Haavikko, Cameriere, Nolla and lastly

(28)

REVIEW OF LITERATURE

Page 14

Kagerer et al (2000)35 _{suggested the possibility of age estimation from acellular cementum}

incremental lines.This made use of mineralized, unstained cross-sections of teeth, preferably

mandibular central incisors and third molars. The authors claimed an accuracy of within two

to three years of the actual chronologic age. However, the pathologic state of the

periodontium and/or desmodontium may compromise the precision of ageing.

Sasidhar Singaraju et al (2009)36 conducted a retrospective study using two hundred

panoramic radiographs which were collected from V.S Dental College. Maximum tooth

length, root length and pulp length, root and pulp width at three levels were calculated on

right maxillary canine. The entire samples were divided into three groups and multiple

regression models were calculated. There was no significant difference between

chronological and estimated age. The observed correlation coefficients were 0.89,0.97 and

0.96.All three groups results were closely related to each other and it was found to be fairly

accurate.

Olze et al (2010) 37_{determined determined the stages of third molar eruption in 347 female}

and 258 male First Nations people of Canada aged 11 to 29 years based on radiological

evidence from 605 conventional orthopantomograms. The results presented here provide data

on the age of alveolar, gingival, and complete eruption of the third molars in the occlusal

plane that can be used for forensic estimation of the minimum and most probable ages of

(29)

REVIEW OF LITERATURE

Page 15

Medha Babshet et al (2010) 38_{used Italian formula to estimate the age of Indian population}

aged between 20-70years by using intraoral periapical digital radiographs of mandibular

canines which were taken by using paralleling technique. Mean absolute error was 11.58

years and 10.76 years for Italian and Indian formula respectively. No apparent difference was

observed between these two formulas.

Jayaraman et al (2011) 39 validated the applicability of Demirjian’s dataset on a southern

Chinese population. A total of 182 dental panoramic tomographs comprising an equal

number of boys and girls with an age range from 3 to 16 years were scored. Dental maturity

scores were obtained from the Demirjian’s dataset and dental age was calculated. The

difference in chronological and estimated dental ages was calculated using the paired t-test.

There was a mean overestimation of dental age of 0.62 years for boys (p<0.01) and 0.36

years for girls (p<0.01). He concluded that Demirjian’s dataset is not suitable for estimating

the age of 3-16 years old southern Chinese children.

Sudhanshu Saxena et al (2011) 40_{developed a method for estimating the chronological age}

of Indian adults based on morphologic variables of canine teeth from 120

orthopantomographs. Pulp/tooth area ratio, pulp/root length ratio, pulp/root width at the

cement-enamel junction level, pulp/root width ratio at mid root level, and pulp/root width

ratio at the midpoint between the cement-enamel junction and the mid root of the canine

were calculated. The estimated age in the total sample ranged from -2.2 to 1.5 years. No

(30)

REVIEW OF LITERATURE

Page 16

Jagannathan et al (2011)41_{evaluated the suitability of pulp/tooth volume ratio of}

mandibular canines for age prediction in an Indian population using Volumetric

reconstruction of scanned images of mandibular canines of 140 individuals, age groups

ranging between 10 – 70 years. While using the Belgian formula for Indian population, the

mean absolute errors of 15.34 years, and 8.54 years error was obtained by regression

equation which was lower than those derived from former. Hence, they stated that specific

formula has to be applied to estimate the age of each population.

Jayanth Kumar et al (2011)42 _{evaluated the reliability of age estimation using Demirjian's}

8 teeth method following the French maturity scores and India specific formula.The study

was conducted on 121 archived digital orthopantamographs which were predominantly

pre-treatment orthodontic radiographs from patients without any obvious developmental

anomalies The radiographs were evaluated as per Demirjian's criteria and age was calculated

using the formula developed for the Indian population.The results showed that the mean

absolute error for the study sample was 1.18 years; in 57.9% of cases the error rate was

within ±1 year. The age estimation using this method narrows down the error rate to just over

one year making this method reliable. However the inclusion of third molar increases the

error rates in the older individuals within the sample.

Chandramala et al (2012)43 concluded a study included 100 subjects of either sex between

age group of 20 and 80 years for assessment of age out of which 56 were males and 44 were

(31)

REVIEW OF LITERATURE

Page 17

years for females. Correlation and regression analysis were carried out. From the results of

regression analysis, it was observed that the coefficient of determination R2 is highest

(0.385) for “Upper second premolar” indicating that age can be estimated better with this

particular tooth when “M” and “W-L” are considered as predictors of age. Both “M” and

“W-L” were found to be significant predictors.

Nithin Agarwal et al (2012)44 conducted a study to assess the chronological age based on

morphological variance of maxillary central incisors. Intra oral periapical radiographs were

taken using paralleling technique from fifty subjects aged between 20-70 years. Length of

tooth,pulp,root and width of root and pulp at three different points were measured.

Regression formulas were used to predict the age and it was found to be fairly accurate.

Bilge Nur et al (2012) 45 _{evaluated the applicability of Demirjian and Nolla methods for}

northeastern Turkish population which was performed on panoramic radiographs of 673

subjects aged 5–15.9 years. The mean dental age (DA) according to the Demirjian and Nolla

methods were compared to the mean chronological age (CA). The mean CA of the study

sample was 10.37±2.90 and 10.03±2.81 years for females and males, respectively. Using the

Demirjian method, the mean estimated DA was 11.26±3.02 years for females and 10.87±2.96

years for males. For Nolla method, the mean estimated DA was 9.80±3.41 and 9.53±3.14

years for females and males, respectively. The mean differences between the CA and DA

(32)

REVIEW OF LITERATURE

Page 18

sample. Nolla method was found to be a more accurate method for estimating DA in

northeastern Turkish population.

Erbudak et al (2012) 46_{examined the correlation between chronological and estimated ages}

and evaluated the feasibility of length and width measurements of pulp cavity for age

estimation. The study population consisted of 123 patients with ages ranging from 14 to 57

years. The measurements of the length and width of six types of teeth on digitized panoramic

radiographs were performed, and the ratios between tooth and pulp cavity measurements

were calculated. Age was estimated using the linear regression models presented by Kvaal et

al. and Paewinsky et al. High differences were observed between chronological and

estimated ages. In conclusion, a difference of more than 12 years in the chronological and

estimated ages derived using regression models in literature was found on panoramic

radiographs in Turkish individuals.

Deepu George Mathew et al (2013)47 conducted a study to develop an independent method

to estimate the age of Indian individuals using mandibular posterior teeth in

orthopantomographs. Eighty eight subjects were included in the study and test subsets.

Adobe photoshop CS5 was used to measure the distance between central fossa to the highest

point on the root furcation and another point was the distance between the roof and floor of

the pulp chamber. The ratio derived between these two measurements was used to estimate

the age.R2 _{value was fairly good and this procedure was found to be fairly accurate to predict}

(33)

REVIEW OF LITERATURE

Page 19

Djukic K et al (2013) 48_{conducted a study that evaluated the accuracy of Demirjian's and}

Willems' methods for dental age estimation in Serbian children population using panoramic

radiographs of 686 children (322 boys and 364 girls) with age range from 4 to 15 years. Both

methods showed discrepancy between obtained and chronological age. The Demirjian's

method overestimated age with a mean accuracy of 0.45 in boys and 0.42 in girls, while

Willems' method showed lower discrepancy (0.12 and 0.16 in boys and girls, respectively).

They suggested that Willem's method was more accurate for estimating dental age in

contemporary Serbian children population.

Sarkar S et al (2013) 49evaluated age in children, adolescents and young adults using

Demirjian's 8-Teeth Method in an Indian population and compared the effectiveness of

existing Demirjian's formula with that of the Indian formula. Among the 100 samples the

mean chronological age in 50 males was 13.44 years and mean chronological age in 50

females was 13.12 years. It was evaluated that the Demirjian's formula underestimated the

mean dental age by 1.63 years in males and by 1.54 years in females, whereas a variation of

0.10 years in male and 0.94 years in female was found with the Indian formula. The mean

dental age obtained using Indian formula was approximating with the chronological age in

the male and female by a margin of 0.94 years. They concluded that Acharya's Indian

formula was more effective in evaluating the dental age closer to the chronological age of an

(34)

REVIEW OF LITERATURE

Page 20

Ambarkova et al (2013)50_{analyzed panoramic radiographs of 966 children (485 female and}

481 male, aged 6–13 years) treated at the University and Community Dental Clinics in

Skopje using four Demirjian methods and a Willems method for determining dental ages.

Intra-rater and interrater agreement of mineralization stages were 0.86 and 0.82, respectively.

All methods significantly overestimated dental age when compared to the chronological age

(p < 0.001).

Limdiwala et al (2013)51 conducted a study using one hundred orthopantomographs with

Kvaal's criteria (Group A) and 50 orthopantomographs without Kvaal's criteria (Group B)

were included. On the basis of Kvaal's criteria, the difference between chronological age and

real age was 8.3 years. This suggests that the accuracy of this method depends on the

precision of measurements and quality and number of the orthopantomographs.

Mahkameh Moshfeghi et al (2014)52_{conducted a study using 112 panoramic radiographs of}

Iranian patients, to measure the amount of secondary dentin deposition o find out the age of

individuals. Patients aged between 20-70 years were included in the study. Then the

population was divided into two groups, study and test group respectively. Ratios of

pulp/root length, pulp/tooth length and pulp width /root width at three levels in lateral incisor,

canine and first premolar of mandible were calculated using Photoshop 2007.They conducted

(35)

REVIEW OF LITERATURE

Page 21

Caroline Edward Ayad (2014)53 examined 99 Orthopantomgraphs (OPG) to determine its

usefulness of Orthopantomgraphs (OPGs) in the assessment of the Sudanese adult age

compared to chronological age. The pulp root length ,root length, pulp/root ratio , total tooth

length ,crown length of the mandibular canine were measured in mm and the estimated age

was recorded using the mandibular canine measurements .Patients were classified into three

groups ,A was of age <20 years old ,B was of 20 to 27 and C was of age >27. The estimated

age in A and C groups were well correlated with the chronological age in both genders and

no significant difference was detected, but in B group there is a significant difference

between the estimated and chronological age and between males and females measurements.

Mostafa M Afify et al (2014) 54assessed the applicability of pulp tooth ratio of mandibular

canine, first and second premolars in orthopantomographs to estimate the age of an

individual. Total of 500 radiographs were included in the study, aged between 18 to 71 years.

Regression equation was closely correlated with age and standard errors of estimate was

ranged between 4.10 to 5.66 years. So, pulp-tooth ratio method was useful to estimate the age

of individuals.

Aída C. Medina et al (2014) 55 _{examined panoramic radiographs of 238 Venezuelan}

children aged 5-13 years for assessment of dental age using the methods described by

Demirjian and Willem. For the Demirjian method, the mean difference between dental age

and chronological age was 0.62 ± 0.93 years, statistically significant. The mean overestimation was lower for females than for males (females 0.56 ± 0.96 years, males 0.67

(36)

REVIEW OF LITERATURE

Page 22

chronological age was 0.15 ± 0.97 years, not statistically significant. Accuracy was significantly different between genders, performing best for females (females 0.01± 0.96 years, males 0.29± 0.96 years). The Willems method for age estimation was found to be more accurate than the Demirjian method in this sample of Venezuelan children.

Ioannis N.Tsatsoulis et al (2014)56 investigated the effects of age and external irritating

stimuli on the thickness and morphology of pulp chamber floor and ceiling in mandibular

molars. A total of 234 panoramic radiographs were obtained from School of Dentistry,

University of Athens. They calculated pulp chambers ceiling /crown height and pulp

chamber floor/crown height in relation to age and angle of pulp chamber ceiling and floor in

relation to age. There was significant difference in the location of secondary dentin formation

between the two pulp chamber walls. They concluded that increase in the rate of the pulp

chamber ceiling thickness is similar to that of the pulp chamber floor thickness. Age is

related to diminished pulp chamber size. They stated that the external stimuli also have an

effect on the pulp chamber dimensional changes.

Manjushree Juneja et al (2014) 57 conducted a study using panoramic radiographs to

estimate the age of 200 population with the age group of 18-72 years. Radiographic images

of maxillary canines (RIC) were processed using a computer –aided drafting program.

Following variables were recorded namely, pulp/root length, pulp/tooth length, pulp/root

width at enamel-cementum junction level, pulp/root width at mid-root level, pulp/root width

(37)

REVIEW OF LITERATURE

Page 23

these variables, the mid-root level and pulp/tooth area ratio showed strong correlation

coefficient and the estimated error was 3.012 years. They concluded that there was

significant correlation between age and morphological variables of canine.

Rezwana Begum Mohammed et al (2014)58 assessed the developmental stages of left

seven mandibular teeth for estimation of dental age (DA) in different age groups and to

evaluate the possible correlation between DA and chronological age (CA) in South Indian

population using Willems method. Digital Orthopantomogram of 332 subjects (166 males,

166 females) who fit the study and the criteria were obtained. Assessment of mandibular

teeth (from central incisor to the second molar on left quadrant) development was undertaken

and DA was assessed using Willems method. The present study showed a significant

correlation between DA and CA in both males (r = 0.71 and females (r = 0.88). The overall

mean difference between the estimated DA and CA for males was 0.69 ± 2.14 years (P <

0.001) while for females, it was 0.08 ± 1.34 years (P > 0.05). Willems method

underestimated the mean age of males by 0.69 years and females by 0.08 years and showed

that females mature earlier than males in selected population. The mean difference between

DA and CA according to Willems method was 0.39 years and is statistically significant (P <

(38)

REVIEW OF LITERATURE

Page 24

Jurca et al (2014) 59_{conducted on X-rays of 285 children aged between 6-13 years. Dental}

age was determined based on the degree of mineralisation of the seven left mandibular teeth,

and t-tests were used to assess the difference between dental age and chronological age

within each age category. Dental age was more advanced in girls in almost all age groups,

whereas in boys just the 6-7 and 8-9 age groups presented a more advanced dental age. The

results of the study showed that Demirjian’s method has some limitations for a Romanian

population, and that these standards are applicable only in certain age groups.

Patil et al (2014) 60conducted a study which evaluating the accuracy of age estimation

formula of Kvaal and coauthors developed for Norwegian population. 100 subjects between

the age group 20 and 50 years digitized intraoral periapical (IOPA) radiograph of maxillary

central incisors was taken and length and width of the teeth were measured and their ratios

were calculated and applied to Kvaal and coauthors formula. The estimated age and

chronological age were compared, less accurate results were found in sample Indian

population. Modified Kvaal’s formula was then developed by using regression analysis of the

ratios and to evaluate the accuracy of this formula, the study was repeated using same criteria

and methodology on another subjects (101-200).Using Kvaal’s formula standard error of

estimated age was more in sample Indian population when compared with Norwegian

population. Then modified Kvaal’s formula was developed and applied to sample Indian

population, which showed accurate results. This study concluded that formula which was

(39)

REVIEW OF LITERATURE

Page 25

Javadinejad et al (2015)61 _{conducted a study to compare the accuracy of four radiographic}

age estimation methods. Orthopantomographic images of 537 healthy children (age: 3.9-14.5

years old) were evaluated. Dental age of the subjects was determined through Demirjian’s,

Willem’s, Cameriere’s, and Smith’s methods. The mean chronological age of the subjects

was 8.93 ± 2.04 years. Overestimations of age were observed follow-ing the use of

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). However, Cameriere’s method underestimated 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.

Kiran et al (2015)62 conducted a study to evaluate the applicability of Demirjian method and

its comparison with Indian formulas for estimation of dental age in subjects attending a

dental school in South India. A total of 250 individuals (130 males and 120 females) between

7 and 18 years, with orthopantamographs were included in the study. Dental age was

estimated using Demirjian’s and Indian formulas. The mean chronological age of the study

sample was 12.39 ± 3.32 years; while the mean age obtained from Demirjian’s method and

(40)

REVIEW OF LITERATURE

Page 26

years in males and 0.83 years in females (P < 0.05). Indian‑specific regression formulas overestimated dental age by 1.72 years in males and 1.91 years in females (P < 0.05).

Ekta Priya et al (2015) 63 conducted a pilot study to test the applicability of Willem’s

method of dental age assessment at the threshold of 14 years considering prohibition of

employment of children. The sample consisted of 30 males and 30 females. The dental age

estimation was performed by two blinded examiners using Willem’s method. It was seen that

there was underestimation of age in both males and females. The difference in females and

males were -0.29 years and -0.23 years respectively. The scores of dental maturation

described by Willems may be suitable for South Indian children.

Gupta S et al (2015)64 assessed the applicability and compared the methods of dental age

estimation by Demirjian's method and the same method as modified by Willems in Indian

children of the National Capital Region (NCR).The study was conducted using dental

radiographs of 70 orthodontic patients (37 males, 33 females) in the age range 9-16 years

selected by simple random sampling. Orthopantomogram were used to estimate dental age by

Demirjian's method and the Willems method using their scoring tables. Lateral cephalograms

were used to estimate skeletal maturity using CVMI. The latter was compared with

Demirjian's stage for mandibular left second molar.and concluded that Willems method have

proved to be more accurate for age estimation among Indian males, and Demirjian's method

for Indian females. A statistically significant association appeared between Demirjian's

(41)

REVIEW OF LITERATURE

Page 27

Lee SS et al (2011) 65 evaluated validity of Demirjian's and the modified methods in Korean

juveniles and adolescents using 1483 digital orthopantomograms which consist of 754 males

and 729 females in the age range of 3-16 years were collected. New age estimation method

based on Korean population data was calculated. Willems' method was found to be most

accurate followed by new Korean method with slight difference for Korean population for

both sexes and concluded that both Willems' method and new Korean method conducted by

present study were proven to be suitable for Korean population.

Uday Ginjupally et al (2015)66_{designed a study to estimate the age of 200 intra oral}

periapical radiographs of maxillary incisors. Pulp cavity width is measured at cervical and

middle third of maxillary incisors using digital Vernier caliper. Regression formulas were

derived for males and 0.21 years in females. Hence, there was difference between male and

female regarding age prediction.

El Morsi DA et al (2015)67 conducted a study to estimate the age from tooth coronal index

of mandibular premolars and molars of both sides using panoramic radiographs of known

age. Study included 234 Egyptian subjects of known age. The length of tooth crown and that

of coronal pulp cavity were measured in 845 mandibular premolars and 835 mandibular

molars.TCI for premolars was larger than those of molars and it was higher in males than

females. It was concluded that there was highest significant correlation of the second right

(42)

REVIEW OF LITERATURE

Page 28

Indira AP et al (2015)68_{conducted a study using 100 intra oral periapical radiographs of}

both genders aged between 16 and 50 years. The tooth selected for the study was left

maxillary central incisor. The ratio between total pulp length and cervical pulp width was

calculated. There was negative correlation between the age and the variable. Hence, this

study estimated the nearest chronological age of an individual.

Ranjdar M.Talabani et al(2015)69 analysed permanent mandibular first molar on digital

panoramic radiographs of sulaimani population. This study included 96 individuals who were

divided into four groups. The height of coronal pulp cavity and the height of crown of first

molars from all subjects were measured and a regression equation was calculated. There was

a strong negative linear relationship between morphology of mandibular first molars with

chronological age. So, they concluded that study showed a good degree of accuracy in

predicting age.

Smrithi D Veera et al (2015)70 conducted a study using 100panoramic radiographs and the

subjects aged between 20-60 years. Mandibular permanent second premolar and first molar

tooth coronal index was measured. Regression equation was created. There was no difference

(43)

REVIEW OF LITERATURE

Page 29

Nerella Narendra Kumar et al (2016)71_{estimated the age of Davangere population by}

measuring the pulp tooth area ratio using digitized intaoral periapical radiographs of

permanent mandibular second molar. Study subjects aged between 14-60 years of both

(44)

(45)

Page 31

SOURCE OF DATA

The present study was conducted in K.S.R Institute of Dental Science and Research,

Tiruchengode. Those who referred to the oral medicine and radiology department for the

purpose to undergo orthodontic treatment, will be selected randomly for the study were taken

up for the study. Orthopantmographs taken for orthodontic treatment purpose were retrived

from the data and One Intra oral periapical radiograph were taken for the same patient for

this study purpose.

INCLUSION CRITERIA

 Above the age of 8 years

 Only fully erupted mandibular first molar in normal functional occlusion

 Those who give voluntary consent for the study procedure

 Absence of systemic diseases, dental anomalies, nutritional and endocrine problems,

premature birth, and birth defect

EXCLUSION CRITERIA

 Teeth with radio-opaque fillings

 Crowns/prosthesis

 Any associated pathologies

 Malalignment, rotation

(46)

Page 32  Teeth with developmental anomalies

 Attrited teeth

MATERIALS USED:

WILLEMS METHOD:

Digital Panoramic System:SIRONA-ORTHOPHOS XG

Computer : Acer 15.6”HD LED LCD

Image Editing Software ; Adobe Photoshop CS-6

KVAAL’S METHOD:

Dental Radiograph Machine : Confident Dental Equipments

Dental Intra Oral Xray film : Carestream Dental E-speed size 2

Fim holder : Dentsply Rinn holder

Automated processor unit : Velprex Extra-X

Dryer

Tracing sheet

Apsara plantinum pencil

Magnifying glass

Divider

(47)

MATERIALS AND METHODS

Page 33

METHODOLOGY

Patients who referred to the oral medicine and radiology department for the purpose

to undergo orthodontic treatment were selected randomly for the study. Informed consent

was obtained prior to the investigatory procedure. Orthopantmographs was taken for

orthodontic treatment purpose and One Intra oral periapical radiograph in relation to right

mandibular first molar by using paralleling cone technique were taken for the same patient

for this study purpose. The study sample consisted of 75 randomly selected subjects ( males

and females) of age ranging from 8 to years divided into five groups according to age.

Clinical examination of all 75 individuals was performed and name, sex, and date of birth of

each individual and date of radiography were recorded. CA of an individual was calculated

by subtracting the birth date from the date on which the radiographs were exposed for that

particular individual. The dental age was determined using orthopantamographs by Willem’s

method and using Intra oral periapical radiograph by Kvaal’s method.

Willem’s method :

The panoramic images were obtained in the Digital Imaging and Communication in

Medicine (DICOM) format, were saved as DICOM files on a computer and were analysed by

using the Adobe Photoshop CS6 image editing program. With the help of Photoshop

generator, the images were enlarged and adjusted with the brightness/contrast, if needed. The

obtained panoramic images were used to assess the status of maturation on the basis of

calcification of the permanent teeth in mandibular right side, from central incisor to the

second molar, using Demirjian et al., method(Table 1).After noting all stages of teeth from

(48)

MATERIALS AND METHODS

Page 34

calculated in years on the basis of tables given by Willems et al,.(Table 2). All the values

from central incisor to the second molar thus obtained were summed to obtain an overall

maturity score, which will indicate the DA of that particular patient.

Kvaal’s method :

Intra-oral periapical radiographs of right mandibular first molar were taken by using

paralleling cone technique. The exposed films were developed in automatic processor in

fresh solutions. The developed X-ray films were dried and subsequently coded. Intra oral

periapical radiographs are traced on tracing sheet. On the radiographs obtained, 15

standardized points were marked, on the basis of the original method for dental age

calculation published by Kvaal et al., and measurements were taken using divider and scale

with millimeter calibrations.

• Tooth length (T)

• Pulp length (P)

• Root length (R)

• Ratio of Pulp width to Root width

• A: Cemento-Enamel Junction

• B: Midpoint between A and C

• C: Midroot level

The ratios calculated were:

P - Pulp length/root length

R - Pulp length/tooth length.

Ratios of the pulp/root width at three different levels:

(49)

MATERIALS AND METHODS

Page 35

At the midpoint between ECJ and mid root level (B)

At the mid root level (C)

The obtained values were applied to the formula developed to estimate the age from right

mandibular first molar given by Kvaal and coauthors.

Age = 33.5 – 18.6 (M) – 3.49 (W − L)

M = 𝑃+𝑅+𝐴+𝐵+𝐶

5

W =𝐵+𝐶

2

L= 𝑃+𝑅

2

W = Mean value of width ratios from level B and C

L = Mean value of length ratios P and R

W − L = Differences between W and L

The estimated age was compared with the chronological age recorded and the efficacy of the

(50)

MATERIALS AND METHODS

[image:50.612.63.532.97.704.2]

Page 36

Table I :Description for developmental stages of tooth

STAGES

DESCRIPTION

A A begining of calcification is seen at the superior level of crypt in the form

of cones. There is no fusion of these calcified points.

B Fusion of the calcified points forms one or more cusps, giving a regularly

outlined occlusal surface

C Enamel and dentin formation is complete at the occlusal surface and

converge at cervical region. Dentin deposition is seen. The outline of the

pulp chamber has a curved shaped at the occlusal border.

D Crown formation is completed down to the cementoenamel junction.

Superior border of pulp chamber in uniradicular teeth has a definite curved

form; projection of pulp horns gives an umbrella top. In molars, pulp

chamber has a trapezoidal form. Begining of root formation is seen in the

form of a spicule

E

Uniradicular teeth

The walls of pulp chamber form straight lines, whose continuity is broken

by the pulp horn. The root length is less than the crown height.

In Molars

Initiation of radicular bifurcation is seen as a calcified point or a semi-lunar

(51)

MATERIALS AND METHODS

Page 37

F Uniradicular teeth

The walls of pulp chamber form isosceles triangle. Apex ends in a funnel

shaped. The root length is equal to or greater than the crown height.

In molars

The bifurcation has developed down to give the roots a distant outline with

funnel shaped endings. Root length is equal to or greater than crown

height.

G The walls of root canal are now parallel and its apical end is partially

open(distal root in molars)

H The apical end of the root canal is completely closed. Periodontal

(52)

MATERIALS AND METHODS

[image:52.612.61.541.97.659.2]

Page 38

Table 2 : Developmental status of a particular tooth by Willems et al.,

GENDER TOOTH A B C D E F G H

Boys Central

Incisor

- - 1.68 1.49 1.5 1.86 2.07 2.19

Lateral Incisor - - 0.55 0.63 0.74 1.08 1.32 1.64

Canine - - - 0.04 0.31 0.47 1.09 1.9

First Bicuspid 0.15 0.56 0.75 1.11 1.48 2.03 2.43 2.83

Second

Bicuspid

0.08 0.05 0.12 0.27 0.33 0.45 0.4 1.15

First Molar - - - 0.69 1.14 1.6 1.95 2.15

Second Molar 0.18 0.48 0.71 0.8 1.31 2 2.48 4.17

Girls Central

Incisor

- - 1.83 2.19 2.34 2.82 3.19 3.14

Lateral Incisor - - - 0.29 0.32 0.49 0.79 0.7

Canine - - 0.6 0.54 0.62 1.08 1.72 2

First Bicuspid -0.95 -0.15 0.16 0.41 0.6 1.27 1.58 2.19

Second

Bicuspid

-0.19 0.01 0.27 0.17 0.35 0.35 0.55 1.51

First Molar - - - 0.62 0.9 1.56 1.82 2.21

(53)

MATERIALS AND METHODS

[image:53.612.153.480.127.614.2]

(54)

[image:54.612.131.467.156.645.2]

(55)

[image:55.612.199.428.159.384.2]

Page 41

Figure 3 – Dental Intra Oral Xray Film

(56)

[image:56.612.131.462.100.344.2]

Page 42

Figure 5 – Automatic Processor

[image:56.612.130.463.413.670.2]

(57)

[image:57.612.152.480.128.387.2]

Page 43

Figure 7-Tooth Length

[image:57.612.150.483.427.702.2]

(58)

Page 44

[image:58.612.138.462.111.371.2]

Figure 9 – Root Length

(59)

(60)

STATISTICAL ANALYSIS

Page 45

STATISTICAL ANALYSIS

The data obtained from the study was entered in Microsoft Excel and was given

for statistical analysis. The data was analysed using Statistical Package for Social

Sciences(SPSS) software version 16.0(Windows version 17.0 SPSS

Inc.,Chicago,IL,USA).The level of significance (α) was fixed at 5% (p≤0.05).

PAIRED t TEST :

Student’s t test was used to analyze the significance between the two different age

estimation methods. Paired t test is applied when there is a pair of data from single element in

an observation .Data are collected by two different methods for a same person, so that the

same group participated in both the methods. Then the mean of both the groups are compared

(61)

(62)

RESULTS

Page 47

Descriptive analysis

The study comprises of 24 males and 51 females of age ranging from 7-32 years. The

subjects were divided into five groups ,where 7 males and 8 females of age ranging from

27-32 years were in group I, 7 males and 8 females of age ranging from 22-26 years were in

group II, 5 males and 10 females of age ranging from 17-21 years were in group III, 2 males

and 13 females of age ranging from 12-16 years were in group IV ,3 males and 12 females of

(63)

RESULTS

[image:63.612.67.527.122.382.2]

Page 48

Table III : Distribution of the subjects by their age and gender

Group Age ranges Male Female Total

No. % No. %

I 27-32 years 7 47 8 53 15

II 22-26 years 7 47 8 53 15

III 17-21 years 5 33 10 66.7 15

IV 12-16 years 2 13 13 86.7 15

(64)

RESULTS

[image:64.612.87.588.113.657.2]

Page 49

Table IV : ILLUSTRATING THE RESULTS OBTAINED FROM KVAAL’S METHOD (GROUP 1)

S.No GENDER CA P R M W L KVAAL METHOD

DA

1 Female 27 1.22 0.74 0.73 0.7 1.64 16.6

2 Male 30 1.05 0.73 0.71 0.6 0.89 19.1

3 Female 28 1.17 0.81 0.76 0.7 1.02 18.2

4 Male 28 1.23 0.81 0.76 0.7 1.02 18.2

5 Male 29 1.05 0.78 0.70 0.6 0.91 19.32

6 Female 29 1.15 0.76 0.62 0.45 0.95 20.22

7 Male 29 1.11 0.82 0.69 0.5 0.96 19.2

8 Female 29 1.12 0.76 0.71 0.5 0.97 18.9

9 Female 27 1.17 0.76 0.74 0.6 0.97 18.46

10 Female 31 1.07 0.73 0.74 0.7 0.9 19.04

11 Female 27 1.05 0.73 0.72 0.6 0.89 19.17

12 Male 28 1.23 0.81 0.76 0.7 1.02 18.2

13 Female 26 1.12 0.76 0.71 0.5 0.97 18.9

14 Male 27 1.05 0.78 0.70 0.6 0.9 19.32

15 Male 29 1.05 0.73 0.71 0.6 0.8 19.17

P - Pulp length/root length; R - Pulp length/tooth length; M – mean value of all length and width; W - Mean value of width ratios from level B and C;L -Mean value of length ratios P

(65)

RESULTS

Page 50

Table V: ILLUSTRATING THE RESULTS OBTAINED FROM KVAAL’S METHOD

(GROUP 2)

S.No GENDER CA P/L R/L M W L KVAAL METHOD DA

1 Female 20 1.4 0.76 0.77 0.6 1.08 20.85

2 Female 20 1.13 0.68 1.45 0.4 1.95 11.08

3 Female 20 1.14 0.64 1.32 0.55 1.9 13.71

4 Female 20 1.07 0.65 0.64 0.5 0.86 22.9

5 Male 20 1.12 0.69 0.7 0.61 0.91 21.5

6 Female 19 0.88 0.66 0.6 0.55 0.77 22.7

7 Female 21 1.21 0.63 0.71 0.65 0.92 21.24

8 Female 23 1.15 0.75 0.73 0.61 0.95 21.11

9 Male 21 1.13 0.77 0.69 0.55 0.95 22.09

10 Male 22 1.18 0.8 0.7 0.5 0.99 22.2

11 Male 22 1.14 0.77 0.7 0.77 0.95 18.37

12 Male 22 1.28 0.09 0.63 0.7 0.69 21.79

13 Male 22 1.14 0.8 0.66 0.5 0.97 19.6

14 Female 22 1.16 0.82 0.72 0.5 0.99 18.47

15 Male 21 1.16 0.77 0.71 0.6 0.97 19.09

(66)

RESULTS

Page 51

Table VI : ILLUSTRATING THE RESULTS OBTAINED FROM KVAAL’S METHOD

(GROUP 3)

1 Male 18 1.125 0.66 0.75 0.68 0.9 20.31

2 Female 18 1.14 0.63 0.66 0.62 0.88 22

3 Female 20 1.13 0.652 0.68 0.62 0.9 21.63

4 Male 20 1.14 0.8 0.66 0.5 0.97 19.6

5 Female 19 1.13 0.68 0.7 0.6 0.91 21.52

6 Female 20 1.15 0.75 0.56 0.35 0.95 25.17

7 Female 20 1.13 0.77 1.22 0.6 1.65 14.47

8 Female 21 1.125 0.66 0.75 0.68 0.9 20.31

9 Female 21 1.23 0.89 0.78 0.65 1.06 17.5

10 Female 21 1.33 0.8 0.84 0.75 1.06 16.79

11 Male 19 1.26 0.78 0.71 0.5 1.02 18.5

12 Female 17 1.23 0.89 0.78 0.65 1.06 17.5

13 Female 18 1.24 0.66 0.8 0.75 0.95 17.92

14 Male 17 1.09 0.75 0.72 0.65 0.92 19.16

15 Male 16 0.11 0.09 0.32 0.5 0.1 26.15

(67)

RESULTS

Page 52

Table VII: ILLUSTRATING THE RESULTS OBTAINED FROM KVAAL’S METHOD

(GROUP 4)

1 Female 14 1.23 0.76 1.34 0.65 1 9.82

2 Female 14 1.06 0.65 1.48 0.7 1.95 10.36

3 Female 15 1.14 0.63 0.77 0.74 0.8 9.76

4 Female 14 1.07 0.74 0.74 0.65 0.9 18.86

5 Female 13 1.07 0.74 0.74 0.65 0.9 18.86

6 Male 16 0.63 0.44 0.57 0.65 0.53 22.48

7 Female 13 1.07 0.74 0.74 0.65 0.9 18.86

8 Female 16 1.21 0.77 0.7 0.6 0.99 19.6

9 Female 16 1.13 0.82 0.69 0.5 0.98 18.9

10 Female 14 1.18 0.75 0.76 0.7 0.97 18.42

11 Female 16 1.21 0.77 0.7 0.6 0.99 19.6

12 Female 16 1.13 0.82 0

Comparison of two methods in estimating the relation between dental age and chronological age