Variant root morphology of the third mandibular molar in...

1 d-J- ~ ~ f VARIANT ROOT MORPHOLOGY OF THE THIRD MANDIBULAR

MOLAR IN NORMAL AND IMPACTED TEETH

Investigator Bokindo Isaac Kipyator

V2819582010

BDS III

-1- bull - C) CJ

sect ~

-I- C-J

A research proposal submitted in partial fulfillment of the requirements for the

award of the degree of Bachelor of Dental Surgery University of Nairobi

copy 2014

DECLARA TION

I Bokindo Isaac Kipyator hereby declare that this research proposal is my original work and has

not been presented to any other institution for examination or any other purpose

Sign

Date

APPROVAL I Bokindo Isaac Kipyator IS submitting this research proposal to the Kenyatta National

Hospital University of Nairobi Research Ethics and Standards committee for approval

ln~tF Date Sign

This research proposal has been submitted with our approval as the University of Nairobi

supervisors

Supervisors

IDr Fawzia Butt BDS (Nbi) FDSRCS MDS-OMFS

Department of Oral and Maxillofacial Surgery

School of Dental Sciences

University of Nairobi

Date Sign

2Prof Francis G Macigo BDS (Nbi) MPH (Nbi) PGD-STI (Nbi)

Department of Periodontology I Community and Preventive Dentistry



110~J-DILfSign~ Date

ii

TABLE OF CONTENTS DECLARATION i

APPROVAL ii

TABLE OF CONTENTS iii

LIST OF ABBREVIATIONS iv

SUMMARy 1

CHAPTER 1 INTRODUCTION AND LITERATURE REVIEW 3

11 INTRODUCTION 3

12 LITERATURE REVIEW 5

121 Types of third molar im paction 5

122 Factors involved in third molar impaction 6

123 Root morphology 6

Chapter 2 PROBLEM STATEMENT AND JUSTIFICATION 8

21 Problem statement 8

22 Justification 8

23 Objectives 8

231 Broad objective 8

232 Specific objectives 8

24 Hypothesis 9

24 Study variables 9

Chapter 3 MATERIALS AND METHODS 10

31 Study area 10

32 Study Population 10

33 Study Design 10

34 Sample size 10

35 Sampling methods 10

36 Inclusion and exclusion criteria 11

37 Data collection instruments and techniques 11

38 Data analysis and presentation 11

39 Ethical Consideration 12

310 Study benefits 12

BUDGET 13

CHEDULE AND TIME FRAME 14

60 REFERENCES 15

DATA SHEET 19

iii

LIST OF ABBREVIATIONS

DA - disto-angular

H - Horizontal

IAN - Inferior alveolar nerve

MA - mesio-angular

OMFS - Oral and Maxillofacial Surgery

SDS- School of Dental Sciences

SPSS - Statistical Package for Social Sciences

UoN - University of Nairobi

V - vertical

iv

SUMMARY Background The prevalence of third molar impaction is high across various population

Extraction of the impacted tooth is usually indicated where there is associated pathology

Surgical difficulty in extraction is described in various classification the most commonly used

ones are the Winters and Pell and Gregory The downside to these classification methods is that

morphology of the roots is not put into consideration Root morphology is known to influence

the eruption of teeth therefore it may have a role in impaction of these teeth The study aims to

describe various root morphologies in different types of impactions and establish any association

between the morphology of the teeth and type of impaction

Objective To describe the various root morphologies in different types of third molar impaction

among residents of Nairobi County visiting the School of Dental Sciences University of Nairobi

Study design Descriptive cross-sectional study

Study Population and Study Area This study will be carried out among patients visiting the

School of Dental Sciences University of Nairobi

Materials and methods 359 panoramic radiographs (179 male and 179 female) will be

obtained from the Radiology Division of the Oral and Maxillofacial department School of

Dental Sciences University of Nairobi The morphology of the roots of the third molar will be

described as straight or dilacerated The number of roots will also be recorded The crown and

root lengths will be measured using a Vernier caliper and the root to crown length ratio will be

calculated

Data management Measurements will be coded tabulated and analyzed using SPSS 17

(version 200 Chicago Illinois) Means standard deviations and variances will be calculated A

P-value of ~005 will be considered significant at a confidence interval of 95 Data will be

1

presented in form of graphs pie-charts and tables Photographs will be used for pictorial

representation

Study benefits The root morphology is useful for a surgeon operatingon and around the third

molar region to plan well and in extension enrich the current methods utilized in grading the

surgical difficulty in extraction of the third molar in which the root component has not been

regarded

2

CHAPTER 1 INTRODUCTION AND LITERATURE REVIEW

11 INTRODUCTION The mandibular third molars are the most frequently impacted teeth in the human dentition 1

accounting for 98 of all impacted teeth2 The incidence of impaction of the third molar has

been reported to vary between 8-84 in various studies There is higher prevalence in females

as compared to males5 Various theories have been put forward to explain the cause of

impaction The main factor has been lack of space in the jaw Others include late eruption of the

tooth 7 and the size of the third molar8

The level of difficulty in extracting impacted third molar has been described in the Pell and

Gregory and the Winters classification9 Various aspects such as level of eruption position of

the tooth in relation to the ramus of the mandible and the angulation of the tooth have been

considered Despite the useful parameters used root morphology of the tooth is not put into

consideration in assessing difficulty in these classification methods The third molar shows the

greatest variation in the root morphology The variation in morphology accounts for the

complications that occur during disimpaction most common being laceration of the inferior

alveolar nerve 10

Majority of the third molars (60-70) studied have two roots 1112 The variations documented on

the mandibular third molar include presence of three roots 13 fused roots one rootll Most

studies on the morphologic variants of the third molar have focused on the number of roots

Literature describing the shape of the root of third molars is scarce despite its importance in third

molar disimpaction The shape of the root may be influenced by the nature of impaction since

developmentally growth of tissue has been shown to be determined by thesurrounding

structures as described in the functional matrix theory proposed by Moss (1962)14 Following

3

this theory it is expected that the nature of the third molar impaction will have a considerable

effect on the shape of the morphology of the third molar Knowledge on the root morphology

will help the surgeon to evaluate the difficulty of the operation and anticipate the complications

that may occur The study therefore aims to describe the various root morphologies occurring in

different types of impaction

4

12 LITERATURE REVIEW The third mandibular molar is the most frequently impacted tooth in the human dentition

Various types of impaction have been observed and documented and classified The role of the

root morphology of the third mandibular molar in impaction is yet to be established

121 Types of third molar impaction The most commonly used classification to assess the difficulty of extracting impacted

mandibular molars are the Wintersl5 and the Pel and Gregory Winters classification is based

on the long axis of the impacted tooth in relation to the long axis of the second molar and as

such the types of impaction in this category include mesial angular horizontal bony vertical and

distal angular impactions The Pell and Gregory classification is based on the vertical relation of

the third molar to the second molar as wel as the relationship of the tooth to the anterior border

of the ramus of the mandible

The Pel Gregory classification

i) Based on vertical relation of the third molar to the second molar

A- The occlusal plane of the impacted tooth is at the same level as the occlusal plane of the

second molar

B- The occlusal plane of the impacted tooth is between the occlusal plane and the cervical line of

the second molar

c- The impacted tooth is below the cervical line of the second molar

ii) Based on the relationship with the anterior border of ramus of the mandible

1- There is sufficient space between the ramus and the distal part of the second molar for the

accommodation of the mesiodistal diameter of the third molar

2- The space between the second molar and the ramus of the

mandible is less than the mesiodistal diameter of the third molar

3- Allor most of the third molar is in the ramus of the mandible

5

The above classifications have been shown not to be a reliable indicator of surgical difficulty in

extraction of impacted lower molars with variable intraexaminer and interexaminer agreementl7

Garcia et al(2000) obtained low sensitivity test on the Pell and Gregory classification and this

can be attributed to the variant root morphology of these teeth in terms the length and the shape

or the roots 18

122 Factors involved in third molar impaction Several theories have been put forward to describe causes of third molar impaction The most

popular has been insufficient development of retromolar space 1920 and this may also be related to

imbalance in the pattern of bone remodeling at the mandibular ramus22 Growth of the condyle

occurs in a vertical direction and has been shown to limit resorption at the anterior aspect of the

ramus of the mandible Unfavourable path of eruption has also been implicated in impactiorr

for instance if the tooth bud is in an abnormal position during development and eruption the

tooth ends up impacted Emes at al(20 11) described the evolutionary decrease in the size of the

jaw disproportionately with teeth and this may been due to the change in diet from the hard

unprocessed foods to the soft processed ones2526 The relatively small jaw is more susceptible to

impactions General factors such as genetics race gender and environmental factors including

dietary habits also playa role in impaction2728 Third molar impaction have been associated with

anterior teeth crowding therefore features of the latter seen in a young patient has been an

indicator of third molar impaction

123 Root morphology Literature has focused on the pattern of impaction of the third molar with little mention of the

role the roots of the third molar play in the management of the condition Carvalho and

Vasconcelos(2011) put forward that the number of root (Plt 0004) and the morphology

(Plt0031) were significant predictors of surgical difficulty The main parameters in root

morphology are dilaceration and length Dilaceration is a developmental disturbance in the shape

6

of teeth whereby there is a sharp bend or curvature in the root of a formed tooth A curvature of

greater than 10deg posses a greater risk than lower values Yamaoka et al(2009) found the relation

between the root angulation and impaction whereby impacted tooth had a higher incidence of

angulated roots The reported prevalence of dilaceration of the roots are very high at 81 30

There is little literature on the length of the roots of the third molar which may influence its

closeness to the mandibular canal and thus the risk of injuring the inferior alveolar nerve (IAN)

during extraction Crown to root length ratios have been shown to show the development of

roots Unfavorable ratios have been found in females31 and this may explain the higher

prevalence of impacted teeth among women Some authors have recommended coronectomy of

impacted wisdom teeth in case the roots are surrounding the mandibular canal32J3 The

morphology of the roots has been shown to influence autotransplantation of the third molar34 in

that the morphology of the root may not favor successful transfer of the third molar into the

socket of another missing molar

Park et al(2013) assessed the number of roots of third mandibular molars in a Korean

population whereby there was high prevalence of two rooted teeth (569) and one rooted

(379i5bull Three rooted teeth were seen in only 19 Higher prevalence of two rooted teeth was

also observed in the Iran population at 73 II Panoramic radiography is the standard imaging

technique for evaluating third molars The sensitivity of these radiographs have been reported to

be fair but the specificity of the radiographs is quite high36

The study therefore aims to describe the various root morphologies occurring in different types

of impaction which will help in surgical approach to this region

7

Chapter 2 PI~OBLEM STATEMENT AND JUSTIFICATION

21 Problem statement

The morphology of the roots of the third molar has been shown to infl uence the clinical decision

pertaining the management of impacted third molars There is high variability in the size and

shape and number of the roots of the third molar more than any other teeth in human dentition

Iatrogenic damage to the IAN is the main complication arising from third molar disimpaction

and it is highly related to the closeness of the tooth and its form Current classifications have not

put into consideration the impact of root morphology in grading the difficulty in surgical

extraction

22 Justification

Although there is overwhelming data on the prevalence of third molar impaction in various populations

including the Kenyan there is little literature that focusses in the role played by root morphology in

assessing surgical difficulty in third molar disirnpaction The present study will aim to investigate the

root forms in various types of impactions Data obtained will enable surgeons have more

informed decision during third molar disimpaction

23 Objectives

231 Broad objective

To describe root morphologies in various types of impaction of the third molar in a Kenyan

population

232 Specific objectives

2 To classify various impacted third molar teeth radiographically

3 To describe the number and the shape of the roots in each of the class of impaction

4 To obtain the ratio of crown to root length of the impacted third molar

8

4 To establish the relationship between the morphology of root and the type of impaction

24 Hypothesis

Alternative hypothesis

Angulated roots increases the risk of occurrence of impacted teeth

24 Study variables

Variables Measures

Social- Demographic Variables Age of the patient in years

Independent Variables Root morphology

Dependent Variables Type of third molar impaction

9

Chapter 3 MATERIALS AND METHODS

31 Study area The study is to be carried out at the Radiology division of the Oral and Maxillofacial(OMFS) Department

School of Dental Sciences (SDS) University of Nairobi (UoN) The SDS is located 5 kilometers from the

Central Business District of Nairobi City along valley road

32 Study Population The population will comprise of patients who have come to seek dental treatment in the SDS

33 Study Design A descriptive cross - sectional study on the root morphology of the impacted third molar

34 Sample size Sample size will be computed using the following formula

Where

z = z value according to the confidence level chosen

P = prevalence of impacted teeth recorded at SDS (62837)

c = 1- confidence interval

Using a confidence level of95 and a Z value of l96

(196)20628(1 - 0628) n=

(1 - 095)2 n= 35898 ~ 359 radiographs

35 Sampling methods Probability sampling will be employed whereby simple random sampling will be utilized

Panoramic radiographs of patients taken from year 2010 until current date of study at the

radiology divisionwill be assed Those that will havemet the selection criteria will be listedfrom

10

the oldest to the newest in terms of the date taken starting from number one A fare coin wi II

tossed with the heads meaning the even numbers selected and the tail odd numbers

36 Inclusion and exclusion criteria

361 Inclusion criteria

1) Radiographs from patients 30 years or older

2) Presence of the 3 molars in ei ther quadrant

362 Exclusion criteria

1) Radiographs lacking good contrast

2) Presence of pathologies such as tumors and cysts

37 Data collection instruments and techniques Radiographs will be retrieved from the computers archives by the radiology assistant The main

researcher will examine the radiographs selecting those that have met the requirements The type

of impaction will be classified using the Pell and Gregory classification as

AlA2A3BIB2B3ClC2C3 and also using the Winters method as mesio-angular (MA)

horizontal (H) vertical (V) and disto-angular (OA) The morphology of the roots will also be

studied under each classification and categorized as either straight or dilacerated with the

number of roots recorded in each The lengths of the longest root and crown will be measured

using a Vernier caliper in rnillimetres

38 Data analysis and presentation The ratio of the crown to the root height will also calculated The results will be coded and

tabulated and analyzed using SPSS v17 (SPSS Inc Chicago IL USA) Students t- test will be

performed to test the relationship between root morphology and type of impaction A p value of

11

lt005 will be considered significant at a confidence interval of95 Photographs tables and

charts will be used for data presentation

39 Ethical Consideration Ethical approval will be sought from the Kenyatta National Hospital-University of Nairobi-

Ethics and Standards Committee before the commencement of the study Permission and

requisite authority will be obtained from the administration of the Radiology Division of OMFS

department SDS VoN Information regarding the subjects will be held with maximum

confidentiality and will not be disclosed to any unauthorized persons Case numbers and not

names will be used throughout the study At the end of the study data sheets will be shredded

310 Study benefits The study will be useful to surgeons operating on the third molar Morphology of the roots of the

third molars will enable proper planning and to anticipate difficulties The research proposal and

report will be presented in partial fulfillment of the requirements for the award of the degree of

Bachelor of Dental Surgery in the University of Nairobi

12

BUDGET ITEM NUMBER OF COST OF TOT AL (Kshs)

UNITS UNIT (Kshs) Proposal Typing and 30 pages of 4 10 1200 development Printing booklets

Internet 15 GB 1500 1500 Stationary(printing 1 ream 1000 1000 papers) Flash disk 1000 1000 Binding proposal 3 copies 100 300

Subtotals 5000 Data Collection Typing and 5 pages each 4 10 200

printing copies

Subtotals 200 Data analysis Data analysis 1000 1000 and report computer package writing Typing and 30 pages of 4 10 1200

printing report booklets Internet 14 GB 1400 1400 Binding report 3 copies 100 300

Subtotals 3900 Miscellaneous 15 of total 1365 expenses Grand Total 10465

13

SCHEDULE AND TIME FRAME

Time of the year Activity

May-July Proposal writing

August Approval

August - September Data Collection

September - October Data analysis and writing of dissertation

November Presentation

14

REFERENCES

I Kaya GS Asian M Omezli MM Dayi E Some morphological features related to

mandibular third molar impaction I ClinExp Dent 20102 12-19

2

Fayad BJ Levy JC Yazbeck C Cavezian R Cabanis EA Eruption of third molars

relationship to inclination of adjacent molars Am J OrthodDentofacialOrthop 2004

F eb 125(2) 200-202

3 Ahlquist M Grondahl H Prevalence of impacted teeth and associated pathology in

middle-aged and older Swedish women Community Dent Oral Epidemiol 1991 19 116-

119

4 Venta I Ylipaavalnierni P Turtola L Clinical outcome of third molars in adults followed

during 18 years I Oral Maxillofac Surg 200462 182-5

5 Hashemipour MA Tahmasbi-Arashlow M Fahimi-Hnzaei F Incidence of impacted

mandibular and maxillary third molars A radiographic study in a Southern Iran

Population Med Oral Patol Oral Cir Bucal 20131340-45

6 Sadetaxecic Samir Prohic Sanjalxomsic AmraVukovic Incidence of impacted

mandibular third molars in population of Bosnia and Herzegovina a retrospective

radiographic study Journal of Health Sciences 20133(2) 151-158

7 Hassan Ali Mandibular cephalometric characteristics of a Saudi sample of patients

having impacted third molars Saudi Dent J 2011 23(2) 73-80

8 Forsberg CM Tooth size spacing and crowding in relation to eruption or impaction of

third molars Am I OrthodDentofacialOrthop 198894( 1 )57-62

9 Susarla SM Dodson TB Estimating Third Molar Extraction Difficulty Subjective and

Objective Factors J Oral and Maxillofac Surg 200563427-34

15

10 HoseiniZarch SH Bagherpour A Javadianlangaroodi A Ahmadian Yazdi A Safaei A

Evaluation of the accuracy of panoramic radiography in linear measurements of the jaws

Iran J Radiol 2011897-102

11 Kuzekanani M Haghani 1 Nosrati H Root and canal morphology of mandibular third

molars in an Iranian population Dent Res Dent Clin Dent Prospects 20126(3)85-8

12 Danilo M Zanello G Rusiel AS Manoel D de Sousa Nero Ricardo GS Jesus DPBraz

Dent J 19989(2) 91-94

13 Plotino G A mandibular third molar with three mesial roots A case report J Endod

200834224-6

14 Moss ML The functional matrix In Kraus BS Reidel RA editors Vistas in

orthodontics Philadelphia Lea and Febiger 1962

15 Winter GB Impacted Mandibular Third Molar St Lous American Medical Book Co

1926

16 Pell GJ Gregory B1 Impacted mandibular third molars Classification and modified

techniques for removal Dent Digest 193339330-338

17 Alrnendros-Marques N Berini-Aytes L Gay-Escoda C Influence of lower third molar

position on the incidence of preoperative complications Oral Surg Oral Med Oral Pathol

Oral RadiolEndod 2006 1 02725-32

18 Garcia A G Sampedro F G Rey 1 G Vila P G Martin M S Pell-Gregory classification

is unreliable as a predictor of difficulty in extracting impacted lower third molars Br I

Oral MaxillofacSurg 200038585-587

19 Bishara SA Andreasen G Third molars a review American Journal of Orthodontics

198383131-137

16

20 Grover PS Lorton L The incidence of unerupted permanent teeth and related clinical

cases Oral Surgery Oral Medicine Oral Pathology 198559420-425

21 Ricardo WF Carvalho Belmiro CEo Assessment of Factors Associated With Surgical

Difficulty During Removal of Impacted Lower Third Molars J Oral Maxillofac Surg

2011 692714-2721

22 Bjork A Prediction of mandibular growth rotation Am J Orthod 196955585-599

23 Lakhani ~J Kadri W Mehdi H Sukhia H Bano A Yaqoob S Anterior crowding - a

possible predictor formandibular third molar impaction J AyubColl Abbottabad

20112363-5

24 Richardson M Changes in lower third molar position in the young adult American

Journal of Orthodontics and Dentofacial Orthopedics 1992 1 02320-327

25 Emes Y Aybar B Serhat Y On the evolution of human jaws and teeth A review Bull

IntAssocPaleodont 2011 537-47

26 Garn SM Leonard WR What did our ancestors eat Nutr Rev 1989 Nov47(11 )337-45

27 Hattab FN Alhaija ES Radiographic evaluation of mandibular third molar eruption

space Oral Surg Oral Med Oral Pathol Oral RadiolEndod 1999 Sep88(3)285-91

28 Polat HB Ozan F Kara I Ozdemir H Ay S Prevalence of commonly found pathoses

associated with mandibular impacted third molars based on panoramic radiographs in

Turkish population Oral Surg Oral Med Oral Pathol Oral RadiolEndod 2008 10541-47

29 Yamaoka M Furusawa K Hayama H Kura T Relationship of third molar development

and root angulation J Oral Rehabil 2001 28 198-205

30 Saraswati FK Balajirao B Mamatha GPClinical and orthopantomographic evaluation of

mandibular third molar 2010 1 (1) 27-30

17

31 Holtta P Nystrom M Evalahti M Alaluusua S Root-crown ratios of permanent teeth in a

healthy Finnish population assessed from panoramic radiographs European Journal of

Orthodontics 200426491-497

32 Matzen LH Christensen J Hintze H Schou S Wenzel A Influence of cone beam CT on

treatment plan before surgical intervention of mandibular third molars and impact of

radiogr~phic factors on deciding on coronectomyvs surgical removal

DentomaxillofacRadiol 201342(1)

33 Pogrel MA Lee JS Muff DF Coronectomy A technique to protect the inferior alveolar

nerve J Oral Maxillofac Surg 2004 621447-52

34 Mendes RA Rocha G Mandibular third molar autotransplantation - literature review

with clinical cases J Can Dent Assoc 200470761-6

35 Jun-Beom Park NamRyang Kim Seojin Park YoungkyungKo Evaluation of number of

roots and root anatomy of permanent mandibular third molars in a Korean population

using cone-beam computed tomography 20137(3) 296-301

36 Atieh MA Diagnostic accuracy of panoramic radiography in determining relationship

between inferior alveolar nerve and mandibular third molar J Oral Maxillofac Surg 2010

Jan68(1)74-82

37 Guthua SW Mwaniki DL A retrospective study of characteristics of impacted

mandibular wisdom teeth in 110 patients treated in Nairobi KenyaAfr Dent J

1992630-3

18

DATA SHEET

Radiograph no

CrICK WHERE APPROPRIATE)

Pell and Gregory (A I) (A2) (A3) (8 I) (82) (83) (C I) (C2) (C3)

Winters (MA) (H) (V) (DA)

Straight ( ) d i lacerated ( )

No of roots (I) (2) (3)

Root length (R)

Crown length (C)

CR ratio

19

UNIVERSITY OF NAIROBI COLLEGE OF HEALTH SCIENCES POBOX 19676 Code 00202 Telegrams varsity (254-020) 2726300 Ext 44355

Ref KNH-ERCUAl153

Bokindo Isaac Kipyator V2819582010 School of Dental Sciences University of Nairobi

Dear Isaac

_-t G (-I

cO ~

KNHuON-ERC Email uonknh_ercuonbiacke Website wwwuonbiacke LinkwwwuonbiackeactivitiesIKNHUoN

KENY ATT A NATIONAL HOSPITAL POBOX 20723 Code 00202 Tel 726300-9

Fax 725272 Telegrams MEDSUP Nairobi

24th August 2014

Research Proposal - clearance -Variant Root morphology of the third mandibular molar in normal and impacted teeth (UP523072014)

Your above proposal refers

This is to inform you that permission has been granted by the KNHUON-Ethics amp Research Committee to carry out research on study titled - Variant Root morphology of the third mandibular molar in normal and impacted teeth

By a copy of this letter I am requesting the relevant persons to accord you the professional support and other materials that may be useful to your research

P ML CHINDIA SECRETARY KNHUONmiddotERC

cc The Principal College of Health Sciences UON The Deputy Director CS KNH The Chairperson KNHUoN-ERC AD Health Information KNH The Dean School of Dental Sciences UoN Supervisors Dr Fawzia Butt Prof Francis G Macigo

Protect to discover

DECLARA TION

I Bokindo Isaac Kipyator hereby declare that this research proposal is my original work and has

not been presented to any other institution for examination or any other purpose

Sign

Date



ln~tF Date Sign


supervisors

Supervisors





Date Sign






ii


APPROVAL ii



SUMMARy 1


11 INTRODUCTION 3







22 Justification 8

23 Objectives 8



24 Hypothesis 9



31 Study area 10


33 Study Design 10

34 Sample size 10







BUDGET 13


60 REFERENCES 15

DATA SHEET 19

iii


DA - disto-angular

H - Horizontal


MA - mesio-angular





V - vertical

iv



















calculated




1


representation




regarded

2















alveolar nerve 10








3






4














second molar


the second molar








5





or the roots 18



















6






















7









extraction

22 Justification






23 Objectives

231 Broad objective


population





8


24 Hypothesis



24 Study variables

Variables Measures




9








Where





(196)20628(1 - 0628) n=

(1 - 095)2 n= 35898 ~ 359 radiographs




10





















11













12





printing copies




13




August Approval




14

REFERENCES



2



F eb 125(2) 200-202



119















15







Dent J 19989(2) 91-94


200834224-6




1926










198383131-137

16





2011 692714-2721




20112363-5















17

















Jan68(1)74-82



1992630-3

18

DATA SHEET

Radiograph no






Root length (R)

Crown length (C)

CR ratio

19


Ref KNH-ERCUAl153


Dear Isaac

_-t G (-I

cO ~




24th August 2014







Protect to discover



ln~tF Date Sign


supervisors

Supervisors





Date Sign






ii


APPROVAL ii



SUMMARy 1


11 INTRODUCTION 3







22 Justification 8

23 Objectives 8



24 Hypothesis 9



31 Study area 10


33 Study Design 10

34 Sample size 10







BUDGET 13


60 REFERENCES 15

DATA SHEET 19

iii


DA - disto-angular

H - Horizontal


MA - mesio-angular





V - vertical

iv



















calculated




1


representation




regarded

2















alveolar nerve 10








3






4














second molar


the second molar








5





or the roots 18



















6






















7









extraction

22 Justification






23 Objectives

231 Broad objective


population





8


24 Hypothesis



24 Study variables

Variables Measures




9








Where





(196)20628(1 - 0628) n=

(1 - 095)2 n= 35898 ~ 359 radiographs




10





















11













12





printing copies




13




August Approval




14

REFERENCES



2



F eb 125(2) 200-202



119















15







Dent J 19989(2) 91-94


200834224-6




1926










198383131-137

16





2011 692714-2721




20112363-5















17

















Jan68(1)74-82



1992630-3

18

DATA SHEET

Radiograph no






Root length (R)

Crown length (C)

CR ratio

19


Ref KNH-ERCUAl153


Dear Isaac

_-t G (-I

cO ~




24th August 2014







Protect to discover


APPROVAL ii



SUMMARy 1


11 INTRODUCTION 3







22 Justification 8

23 Objectives 8



24 Hypothesis 9



31 Study area 10


33 Study Design 10

34 Sample size 10







BUDGET 13


60 REFERENCES 15

DATA SHEET 19

iii


DA - disto-angular

H - Horizontal


MA - mesio-angular





V - vertical

iv



















calculated




1


representation




regarded

2















alveolar nerve 10








3






4














second molar


the second molar








5





or the roots 18



















6






















7









extraction

22 Justification






23 Objectives

231 Broad objective


population





8


24 Hypothesis



24 Study variables

Variables Measures




9








Where





(196)20628(1 - 0628) n=

(1 - 095)2 n= 35898 ~ 359 radiographs




10





















11













12





printing copies




13




August Approval




14

REFERENCES



2



F eb 125(2) 200-202



119















15







Dent J 19989(2) 91-94


200834224-6




1926










198383131-137

16





2011 692714-2721




20112363-5















17

















Jan68(1)74-82



1992630-3

18

DATA SHEET

Radiograph no






Root length (R)

Crown length (C)

CR ratio

19


Ref KNH-ERCUAl153


Dear Isaac

_-t G (-I

cO ~




24th August 2014







Protect to discover


DA - disto-angular

H - Horizontal


MA - mesio-angular





V - vertical

iv



















calculated




1


representation




regarded

2















alveolar nerve 10








3






4














second molar


the second molar








5





or the roots 18



















6






















7









extraction

22 Justification






23 Objectives

231 Broad objective


population





8


24 Hypothesis



24 Study variables

Variables Measures




9








Where





(196)20628(1 - 0628) n=

(1 - 095)2 n= 35898 ~ 359 radiographs




10





















11













12





printing copies




13




August Approval




14

REFERENCES



2



F eb 125(2) 200-202



119















15







Dent J 19989(2) 91-94


200834224-6




1926










198383131-137

16





2011 692714-2721




20112363-5















17

















Jan68(1)74-82



1992630-3

18

DATA SHEET

Radiograph no






Root length (R)

Crown length (C)

CR ratio

19


Ref KNH-ERCUAl153


Dear Isaac

_-t G (-I

cO ~




24th August 2014







Protect to discover



















calculated




1


representation




regarded

2















alveolar nerve 10








3






4














second molar


the second molar








5





or the roots 18



















6






















7









extraction

22 Justification






23 Objectives

231 Broad objective


population





8


24 Hypothesis



24 Study variables

Variables Measures




9








Where





(196)20628(1 - 0628) n=

(1 - 095)2 n= 35898 ~ 359 radiographs




10





















11













12





printing copies




13




August Approval




14

REFERENCES



2



F eb 125(2) 200-202



119















15







Dent J 19989(2) 91-94


200834224-6




1926










198383131-137

16





2011 692714-2721




20112363-5















17

















Jan68(1)74-82



1992630-3

18

DATA SHEET

Radiograph no






Root length (R)

Crown length (C)

CR ratio

19


Ref KNH-ERCUAl153


Dear Isaac

_-t G (-I

cO ~




24th August 2014







Protect to discover


representation




regarded

2















alveolar nerve 10








3






4














second molar


the second molar








5





or the roots 18



















6






















7









extraction

22 Justification






23 Objectives

231 Broad objective


population





8


24 Hypothesis



24 Study variables

Variables Measures




9








Where





(196)20628(1 - 0628) n=

(1 - 095)2 n= 35898 ~ 359 radiographs




10





















11













12





printing copies




13




August Approval




14

REFERENCES



2



F eb 125(2) 200-202



119















15







Dent J 19989(2) 91-94


200834224-6




1926










198383131-137

16





2011 692714-2721




20112363-5















17

















Jan68(1)74-82



1992630-3

18

DATA SHEET

Radiograph no






Root length (R)

Crown length (C)

CR ratio

19


Ref KNH-ERCUAl153


Dear Isaac

_-t G (-I

cO ~




24th August 2014







Protect to discover















alveolar nerve 10








3






4














second molar


the second molar








5





or the roots 18



















6






















7









extraction

22 Justification






23 Objectives

231 Broad objective


population





8


24 Hypothesis



24 Study variables

Variables Measures




9








Where





(196)20628(1 - 0628) n=

(1 - 095)2 n= 35898 ~ 359 radiographs




10





















11













12





printing copies




13




August Approval




14

REFERENCES



2



F eb 125(2) 200-202



119















15







Dent J 19989(2) 91-94


200834224-6




1926










198383131-137

16





2011 692714-2721




20112363-5















17

















Jan68(1)74-82



1992630-3

18

DATA SHEET

Radiograph no






Root length (R)

Crown length (C)

CR ratio

19


Ref KNH-ERCUAl153


Dear Isaac

_-t G (-I

cO ~




24th August 2014







Protect to discover






4














second molar


the second molar








5





or the roots 18



















6






















7









extraction

22 Justification






23 Objectives

231 Broad objective


population





8


24 Hypothesis



24 Study variables

Variables Measures




9








Where





(196)20628(1 - 0628) n=

(1 - 095)2 n= 35898 ~ 359 radiographs




10





















11













12





printing copies




13




August Approval




14

REFERENCES



2



F eb 125(2) 200-202



119















15







Dent J 19989(2) 91-94


200834224-6




1926










198383131-137

16





2011 692714-2721




20112363-5















17

















Jan68(1)74-82



1992630-3

18

DATA SHEET

Radiograph no






Root length (R)

Crown length (C)

CR ratio

19


Ref KNH-ERCUAl153


Dear Isaac

_-t G (-I

cO ~




24th August 2014







Protect to discover














second molar


the second molar








5





or the roots 18



















6






















7









extraction

22 Justification






23 Objectives

231 Broad objective


population





8


24 Hypothesis



24 Study variables

Variables Measures




9








Where





(196)20628(1 - 0628) n=

(1 - 095)2 n= 35898 ~ 359 radiographs




10





















11













12





printing copies




13




August Approval




14

REFERENCES



2



F eb 125(2) 200-202



119















15







Dent J 19989(2) 91-94


200834224-6




1926










198383131-137

16





2011 692714-2721




20112363-5















17

















Jan68(1)74-82



1992630-3

18

DATA SHEET

Radiograph no






Root length (R)

Crown length (C)

CR ratio

19


Ref KNH-ERCUAl153


Dear Isaac

_-t G (-I

cO ~




24th August 2014







Protect to discover





or the roots 18



















6






















7









extraction

22 Justification






23 Objectives

231 Broad objective


population





8


24 Hypothesis



24 Study variables

Variables Measures




9








Where





(196)20628(1 - 0628) n=

(1 - 095)2 n= 35898 ~ 359 radiographs




10





















11













12





printing copies




13




August Approval




14

REFERENCES



2



F eb 125(2) 200-202



119















15







Dent J 19989(2) 91-94


200834224-6




1926










198383131-137

16





2011 692714-2721




20112363-5















17

















Jan68(1)74-82



1992630-3

18

DATA SHEET

Radiograph no






Root length (R)

Crown length (C)

CR ratio

19


Ref KNH-ERCUAl153


Dear Isaac

_-t G (-I

cO ~




24th August 2014







Protect to discover






















7









extraction

22 Justification






23 Objectives

231 Broad objective


population





8


24 Hypothesis



24 Study variables

Variables Measures




9








Where





(196)20628(1 - 0628) n=

(1 - 095)2 n= 35898 ~ 359 radiographs




10





















11













12





printing copies




13




August Approval




14

REFERENCES



2



F eb 125(2) 200-202



119















15







Dent J 19989(2) 91-94


200834224-6




1926










198383131-137

16





2011 692714-2721




20112363-5















17

















Jan68(1)74-82



1992630-3

18

DATA SHEET

Radiograph no






Root length (R)

Crown length (C)

CR ratio

19


Ref KNH-ERCUAl153


Dear Isaac

_-t G (-I

cO ~




24th August 2014







Protect to discover









extraction

22 Justification






23 Objectives

231 Broad objective


population





8


24 Hypothesis



24 Study variables

Variables Measures




9








Where





(196)20628(1 - 0628) n=

(1 - 095)2 n= 35898 ~ 359 radiographs




10





















11













12





printing copies




13




August Approval




14

REFERENCES



2



F eb 125(2) 200-202



119















15







Dent J 19989(2) 91-94


200834224-6




1926










198383131-137

16





2011 692714-2721




20112363-5















17

















Jan68(1)74-82



1992630-3

18

DATA SHEET

Radiograph no






Root length (R)

Crown length (C)

CR ratio

19


Ref KNH-ERCUAl153


Dear Isaac

_-t G (-I

cO ~




24th August 2014







Protect to discover


24 Hypothesis



24 Study variables

Variables Measures




9








Where





(196)20628(1 - 0628) n=

(1 - 095)2 n= 35898 ~ 359 radiographs




10





















11













12





printing copies




13




August Approval




14

REFERENCES



2



F eb 125(2) 200-202



119















15







Dent J 19989(2) 91-94


200834224-6




1926










198383131-137

16





2011 692714-2721




20112363-5















17

















Jan68(1)74-82



1992630-3

18

DATA SHEET

Radiograph no






Root length (R)

Crown length (C)

CR ratio

19


Ref KNH-ERCUAl153


Dear Isaac

_-t G (-I

cO ~




24th August 2014







Protect to discover








Where





(196)20628(1 - 0628) n=

(1 - 095)2 n= 35898 ~ 359 radiographs




10





















11













12





printing copies




13




August Approval




14

REFERENCES



2



F eb 125(2) 200-202



119















15







Dent J 19989(2) 91-94


200834224-6




1926










198383131-137

16





2011 692714-2721




20112363-5















17

















Jan68(1)74-82



1992630-3

18

DATA SHEET

Radiograph no






Root length (R)

Crown length (C)

CR ratio

19


Ref KNH-ERCUAl153


Dear Isaac

_-t G (-I

cO ~




24th August 2014







Protect to discover





















11













12





printing copies




13




August Approval




14

REFERENCES



2



F eb 125(2) 200-202



119















15







Dent J 19989(2) 91-94


200834224-6




1926










198383131-137

16





2011 692714-2721




20112363-5















17

















Jan68(1)74-82



1992630-3

18

DATA SHEET

Radiograph no






Root length (R)

Crown length (C)

CR ratio

19


Ref KNH-ERCUAl153


Dear Isaac

_-t G (-I

cO ~




24th August 2014







Protect to discover













12





printing copies




13




August Approval




14

REFERENCES



2



F eb 125(2) 200-202



119















15







Dent J 19989(2) 91-94


200834224-6




1926










198383131-137

16





2011 692714-2721




20112363-5















17

















Jan68(1)74-82



1992630-3

18

DATA SHEET

Radiograph no






Root length (R)

Crown length (C)

CR ratio

19


Ref KNH-ERCUAl153


Dear Isaac

_-t G (-I

cO ~




24th August 2014







Protect to discover





printing copies




13




August Approval




14

REFERENCES



2



F eb 125(2) 200-202



119















15







Dent J 19989(2) 91-94


200834224-6




1926










198383131-137

16





2011 692714-2721




20112363-5















17

















Jan68(1)74-82



1992630-3

18

DATA SHEET

Radiograph no






Root length (R)

Crown length (C)

CR ratio

19


Ref KNH-ERCUAl153


Dear Isaac

_-t G (-I

cO ~




24th August 2014







Protect to discover




August Approval




14

REFERENCES



2



F eb 125(2) 200-202



119















15







Dent J 19989(2) 91-94


200834224-6




1926










198383131-137

16





2011 692714-2721




20112363-5















17

















Jan68(1)74-82



1992630-3

18

DATA SHEET

Radiograph no






Root length (R)

Crown length (C)

CR ratio

19


Ref KNH-ERCUAl153


Dear Isaac

_-t G (-I

cO ~




24th August 2014







Protect to discover

REFERENCES



2



F eb 125(2) 200-202



119















15







Dent J 19989(2) 91-94


200834224-6




1926










198383131-137

16





2011 692714-2721




20112363-5















17

















Jan68(1)74-82



1992630-3

18

DATA SHEET

Radiograph no






Root length (R)

Crown length (C)

CR ratio

19


Ref KNH-ERCUAl153


Dear Isaac

_-t G (-I

cO ~




24th August 2014







Protect to discover

15







Dent J 19989(2) 91-94


200834224-6




1926










198383131-137

16





2011 692714-2721




20112363-5















17

















Jan68(1)74-82



1992630-3

18

DATA SHEET

Radiograph no






Root length (R)

Crown length (C)

CR ratio

19


Ref KNH-ERCUAl153


Dear Isaac

_-t G (-I

cO ~




24th August 2014







Protect to discover







Dent J 19989(2) 91-94


200834224-6




1926










198383131-137

16





2011 692714-2721




20112363-5















17

















Jan68(1)74-82



1992630-3

18

DATA SHEET

Radiograph no






Root length (R)

Crown length (C)

CR ratio

19


Ref KNH-ERCUAl153


Dear Isaac

_-t G (-I

cO ~




24th August 2014







Protect to discover





2011 692714-2721




20112363-5















17

















Jan68(1)74-82



1992630-3

18

DATA SHEET

Radiograph no






Root length (R)

Crown length (C)

CR ratio

19


Ref KNH-ERCUAl153


Dear Isaac

_-t G (-I

cO ~




24th August 2014







Protect to discover

















Jan68(1)74-82



1992630-3

18

DATA SHEET

Radiograph no






Root length (R)

Crown length (C)

CR ratio

19


Ref KNH-ERCUAl153


Dear Isaac

_-t G (-I

cO ~




24th August 2014







Protect to discover

DATA SHEET

Radiograph no






Root length (R)

Crown length (C)

CR ratio

19


Ref KNH-ERCUAl153


Dear Isaac

_-t G (-I

cO ~




24th August 2014







Protect to discover


Ref KNH-ERCUAl153


Dear Isaac

_-t G (-I

cO ~




24th August 2014







Protect to discover

Variant root morphology of the third mandibular molar in...

Documents

Transcript of Variant root morphology of the third mandibular molar in...