demograph 2.pdf

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ORIGNAL RESEARCH

Journal of Dental Peers, Vol.1, Issue 1, April 2013 10

Status of Third Molars In North Indian Population - A

Radiographic Survey

Bhawandeep Kaur1, Soheyl Sheikh2

_______________________________________________________________

Abstract

Background: With the change in number of life style factors, lack of proper dental care and

genetic factors, the incidence of agenesis and impactions of third molars is increasing.

Material & Method: Panoramic radiographs of 960 males and 880 females of age group

ranging from 18-25 years were selected irrespective of sex, caste, nutritional and socio-

economic status.

Results: Impaction rate was found to be 42.98% having no sexual predilection. Vertical

impaction was of 36.6%, more than mesio-angular 29.2%. Agenesis rate was found to be

15.7%. Bilateral agenesis of third molars in maxilla was more 12.6% as compared to

mandible 0.86%.

Conclusion: Evolutionary changes and genetic factors are predisposing humans for having

agenesis and impaction of the third molars.

Key-words: Agenesis, Impaction, Third Molar.

___________________________________________________________________________

Introduction

Evolution is a complex subject and

many different theories regarding this

concept are emerging. The old ones are

being reexamined in the light of emerging

genetic discoveries.

One common and widely accepted

explanation contends that molars evolved

when human ancestors roamed the Earth

on four legs, more than hundred million

years ago. Due to biological, cultural and

evolutionary changes with time, humans

have experienced a decreased dependency

on all tooth types. This is especially the

case where third molars are concerned.

Anthropologists state that constantly

increasing cerebration of man is enlarging

his brain size at the expense of his jaws1,2.

It is a well known fact that nature

tries to eliminate what is not in use.

Likewise, the advent of civilization and

use of soft and refined diet has eliminated

the human need for large and powerful


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jaws. In this decrease in size, the number

of certain teeth no longer necessary for

function of mastication and feeding, areeither getting increasingly impacted or are

not developing at all. So, the incidence of

the third molars getting impacted or

genetically missing is the highest. Hence,

third molars may be considered as

Vestigial2

Agenesis is the congenitally

absence of at least one permanent tooth. It

is the most frequently encountered dental

anomaly. Since the first reported study by

Albert W. Goblirsch in 19303, there have

been several studies done in various

countries all over the world proving that

the percentage of agenesis of third molar

agenesis is increasing.

An impacted tooth is one which,

because of some impediment, is prevented

from assuming its normal position in the

arch at its physiological time of eruption.

The time of eruption of the third molars is

also variable, starting at the age of 16

years. Averages of eruption times of 17.8,

19.0, 20.5 & 24 years have been reported4.

The third molar is the last tooth to

erupt. Hence it may readily become either

impacted or displaced if there is

insufficient room for it with in the dental

arch4.

It is generally accepted that

patterns of facial growth, jaws and tooth

size are inherited and likely to differ

among populations and races. Previous

studies have shown the incidence of

impaction of third molars as 47.44%

(1970), 68.6% (2003), respectively5,6.

Studies have been conducted to

determine the agenesis of the third molars

in different parts of the world like Jordan,

Australia, Jerusalem, Singapore, South

Korea etc. but no similar study has been

documented till now in North India7-11.

The present study was undertaken

to review the prevalence of agenesis as

well as impaction of third molars in

population of age group 18-25 years.

Aim & Objectives:

The aim and objectives of the study were

as follows:

1. To assess the prevalence of agenesis

of the third molars in age group ranging

between 18-25 years.

2. To assess the prevalence of impacted

third molars in age group ranging between

18-25 years.


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Materials & Methodology:

In this study, a total number of

1840 students which were totally

asymptomatic, of age group ranging from

18-25 years irrespective of sex, status,

caste were selected randomly from

different institutions of M. M. University,

Mullana, Ambala, Haryana. An ethical

clearance was obtained from the ethical

committee of M.M.University,Mullana,

Ambala, Haryana.

The subjects were selected

irrespective of their sex, caste, nutritional

and socio-economic status. Their

demographic data and previous history of

extraction of third molar was recorded in

the designed proforma. The purpose of the

study was explained to them verbally and

written consent was obtained.

Exclusion Criteria:

1. Subjects having history of third

molar extraction were not included

in the study.

2. Subjects having any history of

pain in third molar region, trismus

was not included.

Radiographic procedure was

accomplished by Panoramic machine

(Rotagraph plus, panoramic and

cephalometric machine VILLA SISTEMI

MEDICALLI, 2002, Made in Italy) at 80KVp, 10 mA for 17 seconds with total

filtration of 2.5mm aluminium. 5X12

inches curved rigid aluminium cassette

with green light sensitive intensifying

screens (Konika KR-II) and 5X12 inches

Kodak T-Mat green sensitive panoramic

dental films made in U.S.A. by Eastman

Kodak, Rochester, New York were used in

the study. The radiographs were observed

by two observers and were examined for

the following:

a) Number of third molars present perperson

b) Number of impacted of thirdmolars

c) Number of third molars revealingagenesis

Impacted third molars were also

grouped according to their position as

vertical, horizontal, mesioangular,

distoangular impacted molars

Results

Total number of students examined

was 1840 including 960 males and 880


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females having age group ranging from

18-25 years.

Agenesis of all third molars was

found to be in 104 students (5.65%) as

shown in figure 1. Agenesis of the third

molars was found to be more in males as

compared to females. In maxilla bilateral

agenesis of third molars was found in 232

cases (12.6%) as shown in figure 2. In

mandible bilateral agenesis was found to

be in 16 cases (0.86%). The prevalence of

agenesis of third molars is shown in table

1. Impaction rate was found to be 42.98%

in total subjects as shown in figure 3.

Fi g 1Showing agenesis of all the third molars

Fi g 2:Showing bilateral agenesis of third molars

in maxilla.

F ig 3:Showing impacted all third molars as well

as 37.

The various types of impaction

status of third molars is being summarized

in table 2.

Impaction status of third molars in

male and female was found to be in the

ratio of 1:1.

Impaction status in maxillary and

mandibular dentition was found to be in

the ratio of 1:1.74.

Discussion

The third molars are the last teeth

to erupt in the oral cavity. Since they erupt

at about the time when the youth goes off

in to the world to become wise, they

referred to as wisdom teeth.

The word wisdom tooth is derived

from latin word dens sapientiae. In many

Spanish speaking countries it is called as

the molar of judgement. This is because

when they appear, the person is considered

to have better judgement ability than that


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of a child. Turkish refers the third molar

directly to the age at which wisdom teeth

appear and calls it 20 yas disi which means20th year tooth.

Racial variation, nature of diet,

degree of use of masticatory apparatus and

genetic inheritance can affect the jaw size

and tooth size12, 13.

The third molars are the teeth that

are most common congenitally missing. If

present, the third molars may follow an

abnormal eruption path and become

impacted as a result of the skeletal

insufficiency in the areas where they

normally erupt. Impacted third molars are

developmental pathologic medical

deformities characteristics of a modern

civilization.

To our knowledge, this is the first

study in Haryana, a state in Northern part

of India, to evaluate the status of third

molars in population of age group ranging

from 18-25 years. As such, this study hasthe potential to make a substantial

contribution to ongoing debate on the

outcome of third molars i.e. whether they

should be prophylactically removed or

preserved.

The prevalence of third molar

impaction after examining 1840 subjects

of both sexes was found to be 42.98%.

Previous studies have shown prevalence of

impaction of the third molars as of 20.5%(1959, Nanda & Chawla), 37%

(1993,Vohra FS), 33% (1995, faiez N.

Hatteb),40% ( 1998, Dr. Vandana KV),

68.6% (SL Quick, 2003) respectively5-

7,14,15.

Unlike Hellman, Hugson &

Kugelberg, we observed no sexual

predilection in incidence of third molars

impactions16, 17.

In our results, 7360 third molars-

1160 third molars showed agenesis & out

of remaining 6200 third molars, 4600 were

found to be impacted. Most of the teeth

were in vertical impaction state (36.6%) in

contrary to the findings of previous

studies, which concluded that

mesioangular impaction was the common

state of impacted third molars.(8)

However, prevalence of mesioangular

impaction was 29.2%, distoangular 16%

and horizontal 18% respectively.

In our study, agenesis of the third

molars is found to be 15.7% as compared

to previous studies done by Sandhu 1982

(7.78%), Faeiz N. Hattab 1995 (9.1%),

Daniela Gamba Garib 1995 (20.7%). Our

study has documented prevalence of


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agenesis in the maxilla in 12.6% of

examined subjects which is more as

compared to the subjects exhibitingagenesis of third molars bilaterally in

mandible (0.86%)5, 7, 18.

In our study, total number of 80

subjects right maxillary third molars, 88

subjects left maxillary third molars, 48

subjects left mandibular third molars, 32

subjects right mandibular third molars, 232

subjects bilateral maxillary third molars,

16 subjects bilateral mandibular third

molars & 104 subjects all third molars

showed agenesis on the panoramic

radiographs.

Previous studies have shown

incidence of agenesis is more in males

(Sandhu S.S, 1982) and females (Vohra

F.S, 1993), but our study has revealed no

sexual predilection5, 14.

Previous studies have shown the

incidence of agenesis of the maxillary

third molar on the right side (Vohra F.S)while contrary to these finding our study

has shown no predilection to any side of

maxilla14.

Panoramic radiographic procedure

was selected over the IOPA, due to its

advantage of being a fast process and

wherein the view of entire maxilla-

mandibular region on a single film could

be obtained. The procedure is convenientto patient and requires little expertise of

the radiologist.

The main advantages of this

procedure is that the status of developing

third molars can be viewed, their relation

to inferior alveolar dental canal, type of

impaction and site of third molar can be

easily revealed.

The main advantages of this

procedure is that the status of developing

third molars can be viewed, their relation

to inferior alveolar dental canal, type of

impaction and site of third molar can be

easily revealed.

The growth of maxilla and

mandible ceases by 16-17 years of age.

The mean age of subjects included in this

study was 20.94 years which is very close

to average age of eruption of third molarsreported to be of 20.3 years. Schersten et

al19 suggested that 20-25 years is the most

suitable age for studying the third molars.

DA Vies PL20 showed agenesis of

third molars to be more in females as

compared to males. But contrary to his

findings studies conducted by Hattab FN,


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Lynham A, Mok YY,Thompson GW et al

showed no sexual predilection for agenesis

of the third molars. But in our study results

revealed the agenesis of the third molars

more in males7, 8, 10, 21.

Table 1: Prevalence of Agenesis of the Third molars

TOOTH NUMBER INCIDENCE

18 4.34% (80subjects)

28 4.78% (88 subjects)

38 2.60% (48 subjects)

48 1.73% (32 subjects)

18,28 12.6% (232 subjects)

38,48

18,28,38,48

0.86% (16 subjects)

5.65% (104 subjects)

Table 2:Prevalence of Impacted Third molars

Mesioangular 29.2%

Distoangular 16%

Vertical 36.6%

Horizontal 18%

Conclusion & Summary

Among 1840 subjects of age group

ranging from 18-25 years who were

screened for impacted third molars,

42.98% showed one or more third molars

impacted without any sexual predilection.

Agenesis of third molars was found to be

15.7%. Depending upon the impaction

status, treatment options can be planned

for impacted third molars. But probably

because of changing food habits, there


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may be complete agenesis of third molars

in future, if the same trend continues.

Further in the evolutionary ladder of livingkingdom the presence of third molars in

developed body system of human being

seems irrelevant and loathsome instead of

being helpful and work-worthy as happens

to other living being lower down.

References

1. Anthony R, Silvestry JR, Singh I.The unresolved problem of the

third molar. J Am Dent Assoc

2003;134(4):450-455.

2. Bergman J. Are wisdom teeth(third molars) vestiges to human

evolution. TJ arch 1998;12(3):297-

304.

3. Goblirsch AW. A study of thirdmolar teeth. J Am Dent Assoc

1930;17: 1849-1854.

4. Yamaoka M, Furusawa K,Fujimoto K, Uematsu T.Completely impacted teeth in

dentate and edentulous jaws. Aust

Dent J 1995; 41(3): 169-172.

5. Sandhu SS, Kapila BK. Incidenceof Impacted Third Molars. J Ind

Dent Assoc 1982; 54:441-444.

6. Quek SL, Tay CK, Toh SL, LimKC. Pattern of third molar

impaction in a Singapore Chinesepopulation : A retrospective

radiographic survey. Int J Oral &

Maxillofac. Surg. 2003; 32:548-

552.

7. Hattab FN, Rawashdeh MA,Fahmy MS. Impaction status of

third molars in Jordanian students.

Oral Surg Oral Med Oral Pathol

Oral Radiol Endod 1995;79:24-29.

8. Lynham A. Panoramicradiographic survey of hypodontia

in Australian Defence force

recruits. Aus Dent J 1990;35(1):19-

22.

9. Shapira J, Chaushu S, Becker A.Prevalence of tooth transposition,

third molar agenesis and maxillary

canine impaction in individuals

with Down syndrome. Angle Ortho

2000; 70(4):290-296.

10.Mok YY, Ho KK. Congenitallyabsent third molars in 12-16 years

old Singaporean-Chinese patients:

a retrospective radiographic study.

Ann Acad Med Singapore 1996;

25(6):828-830.


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11.Chung CJ, Han JH, Kim KH. Thepattern and prevalence of

hypodontia in Koreans. Oral Dis2008; 14(7):620-625.

12.Aitasalo K, Lehtinen R, Oksala E.An orthopantomographic study of

prevalence of impacted teeth. Int J

Oral Surg 1972; 1:117.

13.Haralabakis H. Observation on thetime of eruption, congenital

absence and impaction of the third

molar teeth. Tans Eur Orthod Soc

1957; 33:308-312.

14.Vohra FS, Gill AS., Sharma SP. Aradiographic study of agenesis of

third molars in individuals with

clinically absent third molars. J of

Ind Dent Assoc 1993; 64(7):221-

224.

15.Vandana KV, Dayakar MM.Impacted third molars: Prevalence

in rural Indian university students.

J of Ind Dent Assoc 1998; 69:94-

96.

16.Hellman M. Our third molar teeth:their eruption, presence and

absence. Dent Cosmos 1936;

78:750-762.

17.Hugson A, Kugelberg CF. Theprevalence of third molars in a

Swedish population. Anepidemiological study. Commun

Dent Health 1988; 5:121-138.

18.Daniela GG, Zanella NLM, Peck S.Associated dental anomalies: case

report. J. Appl. Oral Sci. 2005;

13(4).

19.Schersten E, Lysell L, Rohlin M.Prevalence of impacted third

molars in dental students. Swed

Dent J 1989;13:7-11.

20.Davies PL. Sexual dimorphism inagenesis of teeth. J Dent Res

1968;47:1198.

21.Thompson GW, Popovich F,Anderson DL. Third molar

agenesis in the Burlington Growth

Centre in Toronto. Commun Dent

Oral Epidemiol 1974;2(4):187-192
http://www3.interscience.wiley.com/journal/121439675/abstract?CRETRY=1&SRETRY=0#c1http://www3.interscience.wiley.com/journal/121439675/abstract?CRETRY=1&SRETRY=0#c1


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Correspondence:1Dr Bhawandeep kaur, Senior Lecturer, Department of Oral Medicine &

radiology, Genesis Institute of Dental Sciences & Research, Ferozepur, Punjab, India

Contact Info:

E mail:[email protected] No: +91 81463756022DrSoheyl Sheikh

2, Professor & HOD, Department of Oral Medicine & Radiology, M.M.

College of Dental Sciences & Research, Mullana, Ambala
mailto:[email protected]:[email protected]:[email protected]:[email protected]

Documents

demograph 2.pdf