3D Finite Element Analysis of Different Techniques of Rigid Internal Fixation in Mandibular Angle Fractures: An In Vitro study

DIFFERENT TECHNIQUES OF RIGID

INTERNAL FIXATION IN MANDIBULAR

ANGLE FRACTURES –

AN IN VITROSTUDY

Dissertation submitted to

The Tamil Nadu Dr. M.G.R. Medical

University

In partial fulfilment of the degree of

MASTER OF DENTAL SURGERY

BRANCH III

ORAL AND MAXILLOFACIAL SURGERY

Urkund Analysis Result

Analysed Document: URKUND CHECK.pdf (D46550380)

Submitted: 1/8/2019 4:32:00 PM

Submitted By: [email protected]

Significance: 5 %

Sources included in the report:

https://www.readbyqxmd.com/keyword/130029 https://www.ncbi.nlm.nih.gov/pubmed/29141673 https://scinapse.io/papers/2017961438

https://healthdocbox.com/Dental_Care/109283972-A-customized-fixation-plate-with-novel- structure-designed-by-topological-optimization-for-mandibular-angle-fracture-based-on-finite-element-analysis.html

Instances where selected sources appear:

“At times our own light goes out and is rekindled by a spark from another

person. Each of us has cause to think with deep gratitude of those who have lighted the flame within us.”

I bow in gratitude to the Almighty God, the creator, who has helped

me to sustain these best and toughest years of my life. For providing me the

immense strength and willpower to complete this work and to whom I owe my

very existence. I also thank the Almighty for His unparalleled grace, superior

protection and guidance throughout the lows and highs of my post graduate

journey. Thank you God for keeping my ship sailing and not failing me in my

journey.

I would like to express my deepest appreciation and sincere thanks to

my guiding light, my mentor and Guide Dr.Mathew Jose., Professor and

HOD, Department of Oral and maxillofacial surgery, Sree Mookambika

Institute of Dental Sciences, Kulasekharam. I thank him from the bottom of

my heart for his time, patience and unyielding faith in me. His constant and

timely advice, support and guidance inspired me to aspire for perfection and

has helped me to complete this dissertation. I could not have imagined for

having a better advisor and mentor for this study. I attribute the level of my

master’s degree to his encouragement and effort and without him this thesis

with whom I started this thesis work and many rounds of discussions on my

project with him, helped me a lot. He not only helped me with my thesis work

but also has influenced me with his level of knowledge, which he has

selflessly passed on to me. With his pearls of wisdom, he made the subject

interesting and understandable for our budding minds. He has constantly

forced me to remain focussed on achieving my goal. He is an example of a

true mentor and guide. I could not have asked for a better mentor or guide for

my post graduate studies. With all the gratitude that I feel and warm regards

that I can muster, I thank you sir for imbibing the precious seeds of

knowledge, patience, discipline and duty, that is a treasure for a lifetime.

I am deeply indebted to Dr.Sajesh, MDS, Professor, my co-guide,

who with his vast knowledge has helped me in my work theoretically as well

as clinically. He is a person with lots of clinical and laboratory knowledge and

at the same time he is very helpful and approachable. He acted as a strong

pillar of support who inspite of his own hectic schedule found time in

correcting this dissertation. He was always available to clear my doubts and

guide me to the light of knowledge with his valuable guidance, suggestions

and tireless pursuit for perfection. He has a strong personality and a heart full

of affection which helped me pass the tough times during my post graduate

programme. I am highly greateful to sir for converting the juvenile me into a

matured person under his wings of knowledge. His words always inspired me

student friendly and with his unique style of convincing the most

uncooperative patients and getting us out of trouble and who is always

approachable for any help at any time and he is the one who taught me how to

manage anxious and apprehensive patients giving me an insight of his

psychological approach.

I express my sincere gratitude to Dr.Sindhuja MDS, Senior lecturer,

also for exchanging her vast knowledge and skills during my post graduate

programme which helped me to enrich my skills.

I express my sincere thanks to Dr. Elizabeth Koshi MDS, Principal,

Sree Mookambika Dental College, Kulasekharam for allowing me to utilize

the clinical material and facilities for the completion of this dissertation.

This endeavour would have been impossible without the help,

guidance and inspiration of Dr.A. Lenin Fred, Principal, Mar Ephraem

College of Engineering and Technology, Marthandam for giving me an

opportunity to conduct the study and for making the right arrangements and

conducting time to time meetings with the corresponding departmental staff. I

am indeed, indebted to him.

I express my sincere thanks to Mr. Leo Bright Singh, Professor,

Department of Mechanical Engineering, Mar Ephraem College of Engineering

with this finite elememt analysis, I am indeed, indebted to him.

I am thankful to Dr.Porchelvan for helping me with the statistical

analysis involved in this study. I am thankful to Dharshan offset printers for

their help in carrying out all the DTP works.

It gives me immense pleasure to thank Dr.Subin Varughese

Mathew, my co-PG, who has been with me throughout my postgraduate life

more like an elder brother, guiding and encouraging me during the happy and

hard moments making this journey a memorable one.

This acknowledgement seems lacking without the mention of my dear

super seniors Dr.Shameem Jamal, Dr. Swaminathan, seniors Dr. Abirami,

Dr. Harinee and my dear fellow Post graduates Dr. Aneesha, Dr. Yazhini,

Dr. C.Tamil Selvan and Dr. Saravana Kumar for providing a homely and

fun filled environment and also for their immense support, motivation and

constant encouragement when I slow down. I acknowledge my friends and

batchmates Dr.Swetha, Dr.Blessing , Dr.Tanuja and Dr.Amalor for their

unwavering moral support and motivation in accomplishing this The Greatest

task in my life.

I am also thankful to Mrs. Sunitha and Mrs. Suja Assistants,

Department of Oral and maxillofacial, SMIDS, for their sincere work that

Mrs.Seema and Ms.Priya, Office staffs, SMIDS for their sincere work that

helped me a lot all through my three years of Post Graduate life.

A wave of fond emotions sweep over me as I struggle to gather the

appropriate words, to express the insurmontable respect and warm gratitude I

feel for my father R.Selvaraj, my Mother Carmel Mary, my Brother

Bruno Joe, my Sister Linda, and my better half Dr. Divya M H for their

confidence in me and their sacrifices, strength and encouragement at all times

has been an inspiration and is solely responsible for refurbishing my life and

profession.

“In the end, though, maybe we must all give up trying to pay back

the people in this world who sustain our lives. In the end, maybe it's wiser

to surrender before the miraculous scope of human generosity and to just

SPECIAL ACKNOWLEDGEMENT

I take this opportunity to thank specially our Chairman

Dr.C.K.VELAYUDHAN NAIR MS, Sree Mookambika Institute of Dental

Sciences, our Director Dr.REMA.V.NAIR MD, Sree Mookambika Institute

of Dental Sciences and our Trustees Dr.R.V.MOOKAMBIKA MD, DM,

Dr.VINU GOPINATH MS, MCH and Mr.J.S.PRASAD, Adminstrative

officer for giving me the opportunity to utilize the facilities available in this

SL. NO

INDEX

PAGE NO

1

2

3

4

5

6

7

8

9

10

11

12

i

AO Association for the study of Internal Fixation

FEA Finite Element Analysis

BSSRO Bilateral Sagittal Split Ramus osteotomy

OMS Oral and Maxillofacial surgeons

IGES Initial Graphics Exchange Specifications

CAD Computer aided design

CT Computed Tomography

DICOM Digital imaging and communications in medicine

RS Resorbable screws

RCT Randomized Controlled Trials

CCT Controlled Clinical Trials

MAF Mandibular Angle Fractures

ii

Figure -1 Geometry of Group I

Figure -2 Meshed Work of Group I

Figure -3

``Front Load in Group I 3(A) Equivalent Von Mises 3(B) Equivalent Elastic Strain 3(C) Total Deformation

Figure-4

Ipsilateral Load in Group I 4(A) Equivalent Von Mises 4(B) Equivalent Elastic Strain 4(C) Total Deformation

Figure-5

Contralateral Load in Group I 5(A) Equivalent Von Mises 5(B) Equivalent Elastic Strain 5(C) Total Deformation

Figure-6 Geometry of Group II

Figure-7 Meshed Work of Group II

Figure-8

Front Load in Group II 8(A) Equivalent Von Mises 8(B) Equivalent Elastic Strain 8(C) Total Deformation

Figure-9

Ipsilateral Load in Group II 9(A) Equivalent Von Mises 9(B) Equivalent Elastic Strain 9(C) Total Deformation

Figure-10

Contralateral Load in Group II 10(A) Equivalent Von Mises 10(B) Equivalent Elastic Strain 10(C) Total Deformation

Figure-11 Geometry of Group III

iii

13(B) Equivalent Elastic Strain 13(C) Total Deformation

Figure-14

Ipsilateral Load in Group III 14(A) Equivalent Von Mises 14(B) Equivalent Elastic Strain 14(C) Total Deformation

Figure-15

Contralateral Load in Group III 15(A) Equivalent Von Mises 15(B) Equivalent Elastic Strain 15(C) Total Deformation

Figure-16 Geometry of Group IV

Figure-17 Meshed Work of Group IV

Figure-18

Front Load in Group IV 18(A) Equivalent Von Mises 18(B) Equivalent Elastic Strain 18(C) Total Deformation

Figure-19

Ipsilateral Load in Group IV 19(A) Equivalent Von Mises 19(B) Equivalent Elastic Strain 19(C) Total Deformation

Figure-20

Contralateral Load in Group IV 20(A) Equivalent Von Mises 20(B) Equivalent Elastic Strain 20(C) Total Deformation

Figure-21 Geometry of Group V

Figure-22 Meshed Work of Group V

Figure-23

Front Load in Group V 23(A) Equivalent Von Mises 23(B) Equivalent Elastic Strain 23(C) Total Deformation

Figure-24

iv

vii

LIST OF GRAPHIC DIAGRAMS

GRAPH

NO:1

Graph depicting the Mean and Standard

deviation of Deformation in Group I, Group II,

Group III, Group IV, Group V with Front Load

values

GRAPH

NO:2

Graph depicting the Mean and Standard

deviation of Deformation in Group I, Group II,

Group III, Group IV, Group V with Ipsilateral

Load values

GRAPH

NO:3

Graph depicting the Mean and Standard

deviation of Deformation in Group I, Group II,

Group III, Group IV, Group V with

Contralateral Load values

GRAPH

NO:4

Graph depicting the Mean and Standard

deviation of Von Mises Stress in Group I, Group

II, Group III, Group IV, Group V with Front

Load values

GRAPH

NO:5

Graph depicting the Mean and Standard

deviation of Von Mises Stress in Group I, Group

II, Group III, Group IV, Group V with

Ipsilateral Load values

GRAPH

NO:6

Graph depicting the Mean and Standard

deviation of Von Mises Stress in Group I, Group

II, Group III, Group IV, Group V with

Contralateral Load values

GRAPH

NO:7

Graph depicting the Mean and Standard

deviation of Strain in Group I, Group II, Group

III, Group IV, Group V with Front Load values

GRAPH

NO:8

Graph depicting the Mean and Standard

deviation of Strain in Group I, Group II, Group

III, Group IV, Group V with Ipsilateral Load

values

GRAPH

NO:9

Graph depicting the Mean and Standard

deviation of Strain in Group I, Group II, Group

III, Group IV, Group V with Contralateral Load

1

Introduction :-

The frequent involvement of the mandibular angle in facial fractures can

be attributed to its thin cross-sectional bone area and the common presence of a third

molar. Before the advent of antibiotics, open reduction of mandibular fractures was

associated with a high frequency of infection.

Surgical intervention with stable internal fixation is warranted only if it

results in good anatomic reduction and provides the appropriate milieu for

undisturbed healing.

That is why in vitro biomechanical studies are so important for the development

of the clinical management of fractures. Finite element analysis (FEA) is a numerical

analysis technique that can determine the displacements, stresses, and strains over an

irregular solid body given the complex material behaviour and the loading conditions

imposed upon that body.

Aims and Objectives :-

To find the various stress distribution in mandibular angle fractures

using different plating techniques. The objective of the study is to compare the stress

distribution in bone under occlusal front, occlusal ipsilateral and occlusal

contralateral loads. To compare stress distribution along the angle of the mandible by

using 2.5mm 2 hole, 4 hole and 6 hole plates. To determine which plating technique

is the most ideal one in distributing stresses in the bone so that it will enhance the

2

Methodology :-

A three dimensional finite element model of the mandible with four different

plating techniques were modelled based on the measurements of a human dentulous

mandible using modelling software ‘Solidworks2018’ and was analyzed for stresses

produced in the bone following front, ipsilateral and contralateral biting loads of

different magnitude using ‘ANSYS 18.2 Workbench’.

Results

The results of the study indicated that two plating technique have more

favorable stress distribution in bone compared to other plating techniques.

Summary and Conclusion :-

Based on the observations in this study, it was concluded that two plating

technique showed more favorable stress distribution compared to other plating

techniques and could be considered for use with mandibular angle fractures. However

3

About 19–40 % of all facial fractures are fractures of the mandible, and

12–30 % of all mandibular fractures are fractures of the mandibular angle.1-2 Among

mandibular fractures, the angle is the first most frequent region for fractures caused

by sportive activities, the second most frequent region for fractures caused by

violence, and the third most fractured region in cases of traffic accidents involving

automobiles.3

The frequent involvement of the mandibular angle in facial fractures

can be attributed to its thin cross-sectional bone area and the common presence of a

third molar.4 Before the advent of antibiotics, open reduction of mandibular fractures

was associated with a high frequency of infection.5

Surgical intervention with stable internal fixation is warranted only if

it results in good anatomic reduction and provides the appropriate milieu for

undisturbed healing. If the fracture site is vulnerable to displacing forces, then the

advantages of early function are lost. Consequently, knowledge about the

biomechanical competence, or lack there of, of the individual fixation systems has

important therapeutic ramifications. It is essential that the treatment strategy have a

sound biomechanical basis. Determine the biomechanical competence of individual

fixation systems under controlled and repeatable conditions is an important tool to

investigate a variety of fixation devices and techniques and to optimize device design

on a rational basis.6

That is why in vitro biomechanical studies are so important for the

development of the clinical management of fractures. Finite element analysis (FEA) is

4

strains over an irregular solid body given the complex material behaviour and the

loading conditions imposed upon that body.7

The stress analysis obtained from FEA modelling can provide

information regarding interactions between hardware and bone during normal patient

functioning and perhaps suggest means of lowering the rate of postoperative

complications after open reduction and internal fixation (ORIF) of this trauma.8 _So

this is an in vitro based study to biomechanically investigate the mandibular angle

fractures. This methodology is based on classic studies that establish the use of three

dimensional mandible.9

AN INTRODUCTION TO FINITE ELEMENT ANALYSIS

The Finite Element Analysis (FEA) is the simulation of any given

physical phenomenon using numerical technique for obtaining approximate numerical

solutions to the abstract equations of calculus it predicts the response of physical

systems subjected to external influences.

Finite element analysis is a computer aided mathematical technique

which will provide us with mathematical solutions, so the only way a response of a

system (physical or biological) can be predicted with a Finite element analysis is to

convert the problem from a physical/biological form to a mathematical form and later

on the mathematical solutions to the problem can be interpreted into physical/biologic

terms.

The four concept that are used in Finite element modeling are,

5

The system is typically a physical object composed of various materials, e.g.

solids, liquid, gases or combination of the above.

The domain of problem is typically the region of space occupied by the

system

The governing equations may be a differential equation, integral equation or a

constitutive equation describing the physical properties, & material behavior.

The Loading conditions are externally originating forces, temperature, etc.

that interact with the system causing the state of the system to change. Load acting in

the interior of the domain, i.e. interior load appears as part of governing equation.

Loads acting on the boundary of the domain i.e. boundary loads appears in separate

equation called boundary conditions.

STEPS IN FINITE ELEMENT ANALYSIS

Define a specific problem

•Geometry

•Physical Properties •Loads

Input data to program

•Geometry of domain mesh generation

•Physical properties

•Loads interior and boundary •Type of output desired

FINITE ELEMENT

PROGRAM

Output

•Select type of data •Generate related data

6

In this method domain of the problem is divided into smaller regions

called elements. Adjacent elements touch without over lapping and the there are no

gaps between the elements. The shape of the elements are intentionally made as

simple as possible, such as triangles or quadrilaterals in two dimensional domains

and tetrahedron, pentahedron (wedges or pyramids) and hexahedron (bricks) in three

dimensions. The entire mosaic like pattern of element is called a Mesh. The Mesh

generation is done by preprocessors. In each element the governing equations are

transformed into algebraic equations, called Element Equations, which are an

approximation of the governing equations. Algebraic equations are much easier to

work and are relatively easy to solve.

The terms in the element equations are numerically evaluated for each

element in the mesh, a process best performed on a computer. The resulting numbers

are assembled into a much larger set of algebraic equations called the System

equations. These characterize the response of the entire system so they usually

comprise of a very large number of equations, hundreds of thousands. Such huge

systems of equations can be solved economically because the matrix of coefficients is

"sparse".

Now the boundary conditions are applied which include the boundary

loads. These are imposed by modifying the system equations. This involves adding

values to existing terms and / or shifting terms from one side of the equations to the

other. Both are relatively simple operations.

The system equations are then solved on a computer using

conventional numerical analysis techniques that have been popular for many years,

7

The final operation, called post processing displays the solution to the

system equations in tabular, graphical, or pictorial form. Other physically meaningful

quantities might be derived from the solution and also displayed.

In this method, structures are subdivided into nodes and elements

which facilitates determination of the structural stiffness and ultimately deflection and

stresses (Force =stiffness x Deflection). Material properties such as the Young's modulus (modulus of elasticity) and Poisson's ratio can be utilized by computer generated analysis to describe the mechanical behavior and induced stresses and of a

structure. Calculation of these stresses allows the investigator to determine areas of

high stresses of large deformations which could lead to fracture or failure of the

structure. A general purpose finite element software provides the necessary tools to

perform such analysis for a wide variety of problems without compromising

8

AIMS:

To find the various stress distribution in mandibular angle fractures

using different plating techniques.

OBJECTIVES:

✓ To evaluate the biomechanical behaviour of bone and titanium mini

plates for rigid internal fixation in cases of mandibular angle fractures

using different load values.

✓ To compare the stress distribution in bone under occlusal front, occlusal

ipsilateral and occlusal contralateral loads.

✓ To compare stress distribution along the angle of the mandible by using

2.5mm 2 hole, 4 hole and 6 hole plates.

✓ To determine which plating technique is the most ideal one in

distributing stresses in the bone so that it will enhance the stability as

9

Mongini et al (1981)10_{said that the direct measurement of bone strain in}

living human subjects is impractical, but efforts have been made to do so in

vitro on human material Qualitatively, these observations seem similar to those

in macaque, although direct comparisons are difficult to make. Photoelastic

measurements have also been made on physical models of the mandible, but this

technique does not lend itself to inclusion of in homogeneities in the jaw’s

physical properties.

Ashman et al. (1984)11 _{conducted a study Using an ultrasound}

technique that measured the nine independent orthotropic elastic constants for

small specimens of bone. These specimens, taken from along the length and

around the periphery of human and canine femora, allowed us to map the spatial

variation of the elastic properties of these bones.

Ellis et al (1986)12 _{have shown that inadequate securing of the segments}

can allow a displacement of the distal segment and initiate an early relapse in

animal studies. It has been shown that rigid fixation can provide sufficient

resistance to the displacing forces that encourage micro movements across the

osteotomy site. At the same time, an appropriate immobilization of the

osteotomy gap ensures an uncomplicated healing process, which guarantees

favorable long-term results.

Tom W.P. Korioth et al (1992)13 _{said that the morphology of bone is}

10

variations in its cross-sectional shape and muscle disuse results in a decreased

bone mass. It is also possible that an increased vertical jaw depth is required in

the human mandible when it is called upon to produce high, molar biting forces.

The increased mandibular convexity, however, could also help withstand and

distribute the high corporal bone loads caused by vigorous mastication.

Edward Ellis et al (1993)14 _{treated sixty-five consecutive patients with}

fractures of the mandibular angle by open reduction and internal fixation using

two dynamic compression plates placed through a trans oral incision using

transbuccal trochar instrumentation and 2.4-mm screws. In the first 20 cases, the

screws were inserted without tapping the drill holes. In the remaining 45 cases,

the drill holes were tapped. Overall, 21 fractures (32%) developed infections

requiring secondary surgical intervention. The infection rate was higher in those

fractures where the holes were not tapped (40%) than those cases when the

holes were tapped (29%). Of the 21 fractures that required hardware removal, 9

fractures were healed and required no further treatment; 12 had no firm bony

union and required postsurgical maxillomandibular fixation. Only one case

resulted in a malunion with resulting malocclusion. The use of two dynamic

compression plates was found to be relatively easy, but resulted in an

unacceptable rate of infection.

Niederhagen et al (1996)15 _{performed a prospective study of angle}

fracture treatment over an 8-year period. One hundred eighty-three patients with

mandibular fractures were treated, noting 127 complications using the standard

11

most frequent complication was dehiscence. In addition, more complications

were noted (19.5%) when using the AO technique via an intraoral approach.

Comparison of extraoral AO treatment and monocortical miniplates showed no

significant difference in complication rate (8.1% vs 7.3%). During this study a

transition was made from the AO method to monocortical non compression

miniplates.ose: Similarities in strain patterns between long bones and the ma

Korioth et al (1997)16 _{described about mechanical finite element}

analyses applied to the maxillary and mandibular bone with their associated

natural and restored structures. It includes a description of the principles and the

relevant variables involved, and their critical application to published finite

element models ranging from three-dimensional reconstructions of the jaws to

detailed investigations on the behavior of natural and restored teeth, as well as

basic materials science. The survey revealed that many outstanding FE

approaches related to natural and restored dental structures had already been

done 10-20 years ago. A numerical method for addressing mechanical problems

is a powerful contemporary research tool. FE analyses can provide precise

insight into the complex mechanical behavior of natural and restored

craniofacial structures affected by three-dimensional stress fields which are still

very difficult to assess otherwise.

Teixera et al (1998)17 _{concluded that in a 3-dimensional mandibular}

model, modelling the mandible at distances greater that 4.2 mm mesially or

12

accuracy. The use of infinite elements can be a good way to model boundary

conditions.

Zhou et al (1999)18 _{Most FEA studies modelling the mandible set the}

boundary conditions as fixed. Recently, Zhou et al developed a more realistic

3-dimensional mandibular FEA model from transversely scanned CT image data.

Maurer et al (1999)19 _{studied four different commonly accepted rigid}

fixation methods which were chosen to undertake a comparison with each other

in a computer. A three-dimensional finite element analysis was selected to

evaluate the complex stress fields under posterior occlusal load condition in and

around rigid fixation screws and plates, which were used to stabilize the

proximal and distal segments after the BSSRO advancement procedure. The

three-dimensional finite element analysis allows for a more realistic

representation of the stress distribution in the fixative material and the adjacent

bone tissue than would be the case with a two-dimensional simulation.

Dirk Vollmer et al (2000)20 _{achieved a correlation coefficient of 99.2%}

establishing confidence in the validity of the computed results. Due to a number

of simplifying assumptions made in the construction and in the analysis of the

FE model, comparison between experimental and mathematical data should

integrate the masticatory system implemented to evaluate the accuracy of the FE

model. One particular point of interest in the FEA is the analysis of various

biomechanical parameters (stress, strain and displacement) within the mandible.

13

of information on teeth, the lack of detailed knowledge regarding the material

properties of cancellous bone, the uncertainty of how to realistically distribute

the muscle loading and the difficulty of knowing how to model the boundary

conditions of the condyles. Therefore, validation of the model could only be

accomplished by comparing the computed results with observed and measured

responses. The results of the FEA in terms of strain distribution accorded well

with the experimental data.

Andrew J.L. Gear et al (2001)21 _{conducted a survey which showed}

among 104 surgeons who treat mandible fractures, 86 (83%) treat more than 10

mandibular fractures per year. Preferred techniques for simple, non comminuted

mandibular angle fractures in this group were: single miniplate on the superior

border (Champy technique) with or without arch bars (44 surgeons, 51%);

tension band plate on the superior border and non locking, bicortical screw plate

on the inferior border (11 surgeons, 13%); dual miniplates (9 surgeons, 10%); a

locking screw plate on the inferior border only (6 surgeons, 7%), and

3-dimensional plates (5 surgeons, 6%). Eleven surgeons (13%) gave multiple

answers. Surgeons who treat more than 10 fractures per year favour the Champy

technique over the tension band and bicortical plate combination (44 [51%] vs

11 [13%]), while those surgeons who treat less than 10 per year favour the

tension band and bicortical plate combination over the Champy technique (9

[50%] vs 3 [17%]. This survey suggests an evolution in the management of

mandibular angle fractures. A single miniplate plate on the superior border of

14

When using large, inferiorly based plates more surgeons are now favouring

neutral rather than eccentric screw placement.

Gabreilli et al (2003)22_{, conducted a study and recorded of 191 patients}

who experienced a total of 280 mandibular fractures that were treated with

2.0-mm miniplates were reviewed. One hundred twelve of those patients, presenting

160 fractures, who attended a late follow-up were also clinically evaluated.

Miniplates were used and no intermaxillary fixation was used. All patients

included had a minimum follow-up of 6 months. Demographic data, procedures,

postoperative results and complications were analyzed. Mandibular fractures

occurred mainly in males (mean age, 30.3 years). Mean follow-up was 21.92

months. The main etiology was motor vehicle accident. The most common

fracture was the angle fracture (28.21%). Twenty-two fractures developed

infection, for an overall incidence of 7.85%. When only angle fractures are

considered, that incidence is increased to 18.98%. Although only 1 patient

(0.89%) described inferior alveolar nerve paresthesia, objective testing revealed

sensitivity alterations in 31.52% of the patients who had fractures in regions

related to the inferior alveolar nerve. Temporary mild deficit of the marginal

mandibular branch was observed in 2.56% of the extraoral approaches

performed and 2.48% presented with hypertrophic scars. Incidence of occlusal

alterations was 4.0%. Facial asymmetry was observed in 2.67% of the patients,

whereas malunion incidence was 1.78Mean mouth opening was 42.08 mm.

Mercedes gallas torreira et al (2004)23 _{conducted a computer based}

study which was made to assess the stress patterns within human mandibles

15

nodes and 30.119 tetrahedra. A commercial finite element solver was then

applied to this mesh to compute stresses generated in standard trauma situations

(a blow in the symphysis region and another one to the body of the mandible).

The results indicate that following a blow to the symphysis region, maximum

stress areas were located at the symphysis, retromolar and condylar regions. In

the case of a blow to the mandibular body, the maximum stress areas were

located at the contralateral angle, the ipsilateral body and the ipsilateral

condylar neck regions.The main application of this study was the prediction of

fractures as a consequence of known forces.

A H Choi et al (2005)24 _{studied a newer design (CAD) methods and to}

16

E. Erkmen et al. (2005)25 _{created a three dimensional finite element}

model of the mandible to simulate and study the biomechanical loads of

osteosynthesis screws in bilateral sagittal osteotomy. Using the finite element

method clinical conditions were simulated. When bite forces were applied, the

most stable configuration was found to be a triangular one. A mini screw of 2.0

mm diameter can provide sufficient stability at the osteotomy site after ramus

split osteotomy. Even screws with a diameter of 1.5 mm would withstand forces

up to 89.5 N, which would not normally be reached by patients after ramus split

osteotomy in the early period of healing. Forces exerted by patients after

bilateral ramus split osteotomy do not exceed these values. The finite-element

analysis appears to be an adequate method to evaluate this clinical question of

interest. It might well replace mechanical models and the results are comparable

with those reported in the International literature.

Chacon et al (2005)26 _{found that the scale of displacement was less for}

the titanium plating system compared with the resorbable system. There is only

1 previous study that has compared titanium and resorbable plating systems for

the treatment of mandibular angle fractures, in a single cadaveric mandible; that

study showed significant biomechanical differences between the 2 materials.

Scott T. Lovald et al (2006)27_{, conducted a study on the finite element}

model of the human dentate mandible has been developed to provide a

comparison of fixation systems used currently for fracture reduction. Volume

domains for cortical bone, cancellous bone, and teeth were created and meshed

in ANSYS 8.0 based on IGES curves created from computerized tomography

17

simulated along the symphysis. Results based on Von Mises stress in cortical

and cancellous bone surrounding the screws, and on fracture surface spatial

fixation, show some relative differences between different screw-plate systems,

yet all were judged to be appropriate in their reduction potential.

Conor P. Barry et al (2007)28 _{conducted a study to determine the}

complication rate for patients presenting with isolated mandibular angle

fractures treated by open reduction and internal fixation using a single superior

border miniplate technique. This was a retrospective study of consecutive

patients with isolated mandibular angle fractures treated using a specific

protocol at a Regional Oral and Maxillofacial Department between January

1998 and December 2004. The study population included 50 patients presenting

with isolated mandibular angle fractures, 6 patients (12%) experienced

complications requiring bone plate removal. These complications were minor

and occurred after fracture healing as follows: 4 patients (8%) experienced

superficial soft tissue infection associated with the bone plate, treated with oral

antibiotics, 1 patient (2%) experienced bone plate exposure, and a further

patient (2%) presented with a fractured bone plate. All 6 patients (12%) were

treated by bone plate removal under general anesthesia as elective day case

surgery. The results of this study suggest that the complication rates associated

with the treatment of isolated mandibular angle fractures using a superior border

plating technique, in this patient population, is relatively low (12%). The

complications were all minor in nature. There was a permanent inferior alveolar

18

Alper Alkan et al (2007)29 _{evaluated the biomechanical behaviors of}

different miniplate fixation techniques for treatment of fractures of the

mandibular angle. Twenty sheep hemimandibles were used to evaluate 4

different plating techniques. The groups were fixated with Champy technique,

biplanar plate placement, monoplanar plate placement, and 3-dimensional

curved angle strut plate. A custom-made 3-point biomechanical test model was

used for the samples. Each group was tested with compression forces by an

Instron Lloyd LRX machine. The 3D curved angle strut plate technique had

more favorable biomechanical behavior than the Champy technique but was not

significantly different from biplanar or monoplanar plate placement techniques.

The study demonstrated that 3D strut plates or dual miniplate techniques had

greater resistance to compression loads than the Champy technique. In addition,

biplanar plate orientation may provide a more favorable biomechanical behavior

than monoplanar plate placement.

Randal H Rudderman et al (2008)30 _{reviewed the behavior of the}

human mandible. Behavior of the intact mandible, multiple fracture scenarios,

and small and large (single and multiple) plating applications are reviewed.

Several misconceptions in the literature are clarified. Factors that will resolve

the dichotomy between clinical results and current biomechanical theories are

presented such that a more logical biomechanical model may be used to

approach fixation of the mandibular fracture being treated. Current mandibular

biomechanics theory must be expanded to reflect the complex nature of the

system and to more accurately describe conditions that exist in the physical

world. Otherwise, further analysis in advancements in outcome and treatment

19

Hamdi arbag et al (2008)31_{, did a computer based finite}

element analysis (FEA) to assess the most suitable shape and fixation technique

for a certain type of mandible fracture at corpus. A model of the mandible was

prepared using computed tomography scans. The CT scans were transferred and

converted to the finite element model by means of a procedure developed for

this study. Simulated corpus fractures were fixed with 14 different fixation

configurations of titanium miniplates. The FEA was performed with respect to

displacement and stresses in the titanium miniplates for these configurations.

The study results indicated that the use of 2 straight miniplates is more rigid

than other fixation types. FEA may be useful in evaluation of other plate

constructs, fracture types, and fracture sites, as confirmed by the agreement

between our data and those in the literature and with clinical experience. This

analysis should permit us to suggest and evaluate new miniplate designs and

enable considerable savings to be made in terms of time, material, and animal

experiments in the future development of osteosynthesis materials and

techniques.

Burak Bayramto et al (2009)32 _{performed a study, in order to}

compare the fixation reliability and stability of titanium and resorbable plates

and screws by simulating chewing forces. Mandibular angle fractures in 11

sheep hemimandibles were fixed with 4-hole straight titanium plates and

2.0x7mm titanium screws; in addition, 11 hemimandibles were fixed with

4-hole straight resorbable plates and 2.5x6mm resorbable screws according to the

Champy technique. The hemimandibles were mounted with a fixation device in

20

under 20, 60, 100, 120, 150, and 200 N; maximum displacements; and

maximum forces that the model could resist before breakage were recorded and

compared. Significant differences were found between resorbable and titanium

plates and screws at all forces (20, 60, 100, 120, 150, and 200 N). We found no

statistically significant differences in the breaking force and maximum

displacement values (displacement values at the breaking forces) between the

groups. The stability of mandibular angle fractures with titanium miniplates

under simulated chewing forces was significantly higher than with the

resorbable system. Metallic and resorbable fixation systems cannot be used

interchangeably to treat mandibular angle fractures under similar loading

conditions.

Rudolf Seemann (2010)33_{, studied about the complication rates of}

mandibular angle fractures treated by open reduction were assessed. Three

hundred twenty-two patients (259 men, 63 women) with 335 surgically treated

mandibular angle fractures were included in this study. Fractures were caused

by fights (46.6%), falls (19.2%), traffic accidents (14.6%), sports (11.9%),

wisdom tooth removal (7.3%), and 0.9% other causes. Successful treatment

occurred in 93.69% of fractures with 1 open reduction and in 6.31% with 2 open

reductions. Of surgically treated patients, 71.47% (238) were completely free of

complications. A detailed complication correlation matrix is given in the text.

Ninety-five fractures treated with 1 miniplate, 170 with 2 miniplates, and 70

with other osteosynthesis concepts were compared regarding osteosynthesis

failure and pseudarthrosis. Similar osteosynthesis failure rates were shown for 1

21

Eran Regevet al (2010)34 _{carried a study to use the meta-analysis tool}

to combine information from multiple studies and to compare complication

rates for different fixation methods. An English language literature search was

conducted for articles on mandibular angle fractures. Information was collected

on four variables of interest: compression/noncompression technique,

monocortical/bicortical screws, number of plates, and location of plates. Five

outcome rates were analyzed: infection, reoperation, hardware removal,

malunion, and nonunion. Meta-analyses were run using Comprehensive Meta

Analysis, version 2.2.03. Significantly higher rates of infection, reoperation, and

hardware removal were found for compression compared with noncompression,

two plates compared with one plate, and for plates located on both the inferior

and superior borders as compared with superior or inferior only. The results of

this meta-analysis found lower complication rates with the use of

noncompression, monocortical, and single-plate fixation, supporting the trend

toward a single, superiorly placed, monocortical miniplate for fixation of

mandibular angle fractures.

Hang Wang et al (2010)35_{, did a study to analyze the stress}

distribution in a symphyseal fractured human mandible reduced by 2 different

methods, reduction with 1 miniplate or with 2 miniplates by using finite element

(FE) analysis, and then compared the results with an intact mandible.

Three-dimensional FE models of an intact mandible and symphyseal fractured

mandibles reduced by 2 fixation methods were developed to analyse mandibular

22

clenching in the inter cuspal position and left unilateral molar clenching. Groups

of parallel vectors were used to simulate 9 pairs of masticatory muscles

involved in the 2 static biting tasks. Stress distributions in reduced mandible

with 1 or 2 miniplates were more or less different from that of the intact

mandible. During left unilateral molar clenching, bite forces obviously reduced

after fracture. Bite force and the stress distribution pattern in the mandible

reduced with 2 miniplates were closer to that in the intact mandible. It is

suggested that the effect of the miniplates in stabilizing the continuity-broken

mandible influence the restorations of the stress distribution pattern and bite

force. Two miniplates have a biomechanical advantage over 1 miniplate on

these restorations.

Jae Pyong Choi et al (2010)36 _{evaluated the stress distribution of}

resorbable screw (RS) and cortical/cancellous bone in the mandibular setback

surgery with bilateral sagittal split ramus osteotomy (BSSRO) according to

fixation geometry and number of RSs using three-dimensional finite element

analysis. Three-dimensional virtual models of the mandible and bicortical RS

(INION CPS System; diameter, 2.5 mm; length, 12 mm [Inion Ltd, Tampere,

Finland]) were constructed by Mimics (Materialise,AnnArbor,MI) using three

dimensional computed tomography DICOM data with 0.5-mmthickness cut.

After 8-mm setback BSSRO was performed, fixation between the proximal and

distal segments of the mandible was done with bicortical RS. After applying the

occlusal load of 132 N on the lower first molar, stress distributions of the RSs

and cortical/ cancellous bone in each option were analyzed by ANSYS program

23

anterior RS fixation in the retromolar area in all options. Although 3R1A

fixation showed more even distribution of stress concentration than other

fixation options, 2R1A fixation was comparable with 3R1A fixation in view of

yield stress in RSs. In terms of fixation geometry and number of RSs, both

2R1A and 3R1A fixation configurations might provide proper stress distribution

in BSSRO.

Okumura N et al (2010)37 _{investigated the effect of maxillary}

cortical bone thickness, implant design and diameter on stress around

implants and revealed that regardless of load direction, implant design

and diameter, cortical and cancellous bone stresses increased with the

decrease of crestal cortical bone thickness.

Syed Zakaullah et al (2011)38 _{did a study to evaluate the short-term}

results of patients treated with low-profile titanium miniplates for fracture of the

mandible. Twenty patients with fractures of the mandible were treated by open

reduction and internal fixation using thin, low-profile titanium miniplates and

1.3-mm self-threading screws. Patients were evaluated for complications during

a 6 months follow-up period. One patient (5%) experienced wound dehiscence

and was managed by daily irrigation and antibiotic medication. Conclusion:

Low-profile titanium miniplates can be adequately used for internal fixation in

selective mandibular fractures.

Andre Vajgel et al (2013)39_{, conducted a study computational,}

laboratory-based comparison of the biomechanical stability of 2.0 fixation

24

using 3-dimensional finite element analysis. Three-dimensional finite element

models simulating Class III atrophic mandibular 1.5, 2.0, and 2.5 mm. Fractures

were simulated in left mandibular bodies, and 3 locking screws were used on

each side of each fracture for fixation. Bite forces of approximately 63 N were

simulated in the incisor and molar regions of the mandibles in finite element

models. The level of compressive strain on the bone around the screw was

within the physiological limit. No significant difference was observed in the

displacement of bone segments in the fracture region. Von Mises stress was

higher during simulated bites in the molar region for plates with thicknesses of

1.0 mm. Plate tension values were below the level required for permanent

deformation or fracture in all models. The 2.5mmthick plate presented better

biomechanical performance than all other plates. The 2.0 mm thick plate also

showed satisfactory results and adequate safety limits. Large-profile (2.0 mm

thick) locking plates showed better biomechanical performance than did 1.0 and

1.5mm thick plates and can be considered an alternative reconstruction plate for

the treatment of Class III atrophic mandibular fractures.

Essam Ahmed Al-moraissi et al (2014)40 _{et al designed and}

implemented a systematic review with meta-analysis. Only those studies where

a transoral approach was used (+/- transbuccal instrumentation) were selected.

21 publications were included: eight RCTs, three CCTs and ten retrospective

studies. Eight studies showed a low risk of bias, eleven studies showed a

moderate risk of bias, and one study showed a high risk of bias. There was a

statistically significant difference between a single superior border miniplate

25

meaning that the use of the oneminiplate in the fixation of MAFs decreases the

risk of postoperative complications by 37% compared to using two miniplates.

Comparing a miniplate placed on the external oblique ridge to one placed on the

lateral surface of the mandible resulted in a cumulative OR of 2.10, meaning

that the use of the transbuccal miniplate decreases the risk of postoperative

complications by 110% compared to one on the external oblique ridge.

Comparing geometric to standard miniplates, the OR was 0.29, meaning that the

use of a geometric miniplate decreases the risk of postoperative complication by

71% compared to using conventional miniplates.

Svetlana Anticto et al (2015)41 _{did a study inorder to investigate the}

influences of the presence and position of a lower third molar (M3) on the

fragility of mandibular angle and condyle, using finite element analysis. From

computed tomographic scans of a human mandible with normally erupted M3,

two additional virtual models were generated: a mandibular model with partially

impacted M3 and a model without M3. Two cases of impact were considered: a

frontal and a lateral blow. The results are based on the chromatic analysis of the

distributed von Mises and principal stresses, and calculation of their failure

indices. In the frontal blow, the angle region showed the highest stress in the

case with partially impacted M3, and the condylar region in the case without

M3. Compressive stresses were dominant but caused no failure. Tensile stresses

were recorded in the retromolar areas, but caused failure only in the case with

partially impacted M3. In the lateral blow, the stress concentrated at the point of

impact, in the ipsilateral and contralateral angle and condylar regions. The

26

stresses caused the failure on the ipsilateral side, whereas compressive stresses

on the contralateral side.

Russell Wang et al (2016)42 _{conducted a study to simulate stress}

and strain distribution numerically on a normal mandible under physiological

occlusal loadings. The results were compared to those of mandible that had an

angle fracture stabilized with different fixation designs under the same loadings.

The amount of displacement at two interfragmentary gaps also was studied. A

3D virtual mandible was reconstructed with an angle fracture that had a fracture

gap of either 0.1mm or 1mm. Three types of plate fixation designs were used:

Type I, a mini-plate was placed cross the fracture line following Champy

technique; Type two, two miniplate were used; Type III a reconstruction plate

was used on the inferior border of the mandible. 100N and 500N loads were

applied to the models. Results represent high stresses and strains distributed to

condylar and angular areas regardless of the loading position. The ratio of the

plate/bone average stress ranges from 215% (Type II design) to 848% (Type 1

design), irrespective of the interfragmentary gap size. With a 1 mm fracture gap,

the ratio of the plate/bone stress ranged from 204% (Type II design) to 1130%

(Type 1 design). Interfragmentary gaps between 0.1 mm to 1 mm did not have a

great effect of average stress distribution to the fractured bony segments;

however, they had a greater effect on the stress distribution to the plates and the

screws. Type II fixation was the best mechanical design under bite loads. Type I

design was the least stable system that had the highest stress distribution and the

27

Aysa Ayali et al (2018)43 _{did a study to evaluate the performances of}

5 different plating 3 techniques for fixation of favourable mandibular angle

fractures using the 3D finite element analysis (FEA) method. Five different

miniplate placement configuration alternatives were considered for the fixation

of favorable mandibular angle fractures. The following models were created: a

double parallel miniplate (M1), which was placed at the halfway point of the

mandibular angle height; a ⅓ superior-positioned miniplate (M2); a single

miniplate (M3), which was placed at the halfway point of the mandibular angle

height (½ middle-positioned); a ⅓ inferior-positioned miniplate (M4); and an X

miniplate (M5). Double and ⅓ inferior-positioned miniplates provided the

lowest mechanical stress when compared with the other configurations, whereas

½ middle-positioned single miniplate and X miniplate had the highest stress

levels. In cases of favorable mandibular angle fractures, the authors suggest that

the double miniplate or, if used alone, the ⅓ inferior positioned single miniplate

are adequate rigid fixation methods.

Yun‑feng Liu et al (2017)44 _{proposed this study to design a}

customized fixation plate for mandibular angle fracture using topological

optimization based on the biomechanical properties of the two conventional

fixation systems, and compare the results of stress, strain and displacement

distributions calculated by finite element analysis (FEA). A three-dimensional

(3D) virtual mandible was reconstructed from CT images with a mimic angle

fracture and a 1 mm gap between two bone segments, and then a FEA model,

including volume mesh with inhomogeneous bone material properties, three

28

design a customized plate using topological optimization method, then the shape

of the plate was referenced from the stress concentrated area on an initial part

created from thickened bone surface for optimal calculation, and then the plate

was formulated as “V” pattern according to dimensions of standard mini-plate

finally. All maximum von Mises stresses of mandible were well below the

allowable stress of human bone, as well as maximum principal strain. And the

displacement diagram of bony segments indicated the effect of treatment with

different fixation systems.

Kazuhiro Murakami et al (2017)45 _{concluded in their study to}

evaluate stresses in various types of plates placed for a virtually reduced

unilateral condylar fracture of the mandible using computed tomography–based

3-dimensional finite element (FE) models of a patient to select the optimal plate

system. A computed tomography–based FE model of the mandible of a patient

with a unilateral condylar fracture was constructed. The fracture was virtually

reduced and fixed with 1 straight titanium plate; 2 straight titanium plates; 2

straight poly-L-lactic acid plates; and 4-hole (box), 5-hole (strut), and 7-hole

(lambda) condylar plates. Stresses developing in these plates were analyzed by

applying 478.1 N of bite force at the first molar of the contralateral side of the

mandible. The magnitudes of tensile stress were within the tensile strength in all

types of plates. However, the magnitudes of compressive stress in 1 straight

titanium plate and 2 straight poly-L-lactic acid plates were beyond the

compressive strength. The tensile and compressive stresses of the 5-hole (strut)

plate were the smallest among the 3 types of condylar plates. Fixation by 2

29

indicated for the condylar fracture of this patient. Among these plates, the

5-hole (strut) plate was considered optimal. FE analysis is useful in selecting the

optimal fixation method in the individual patient.

Kazem Khiabani et al (2018)46 _{in their study did the optimal method}

for mini-plating in the fracture of the mandible angle to reach the best

mastication power. A three-dimensional model generated from CBCT

(Cone-beam computed tomography) of human mandible for Finite Element Analysis.

Four different fracture patterns were simulated on the models. Each fracture

pattern was fixed by five different methods of miniplate fixation. Each

compared to others after simulation and applying the force of the masticatory

muscles and result reported in Newton unit. The highest mastication force

belonged to a pattern in which a miniplate was placed on an outer oblique ridge

and another miniplate in the lower border of the buccal mandibular cortex. The

lowest mastication force also belonged to placing a mini plate on the upper side

of the cortex. However, this results show that the use of double miniplates will

improve biting force drastically and it is recommended to place 2 miniplates,

one on the external oblique ridge and the other on the inferior border of lateral

cortex.

Somsak Sittitavornwong et al (2018)47 _{studied The integrity of the}

human mandibular angle fracture after fixation with a single titanium plate

along the upper lateral border to the native human mandible. This

cross-sectional anatomic study involved the left hemi-mandibles of sixteen human

cadavers. They were selected and divided in two groups by remaining dental

30

and gender were noted. The left hemisected native mandibles were mounted at

the condyle and loaded on an Instron 5565 mechanical unit until fracture. The

fractured left hemi-mandible was fixed with a titanium mini-plate and screws.

After plate fixation, each hemi-mandible was again loaded on an Instron 5565

until fracture. Data pertaining to primary outcomes of load application was

recorded in newtons at three different displacement values: 3.0, 5.0, and 7.0

mm, as well as displacement at fixation failure. Key clinical findings of this

project include the inability of single plate mandible fixation to restore the

mandible to pre-injury levels and verification that gender, dental status, and

height of the mandible do not alter the stability of a single plate fixated

mandible.

Bhat V et al (2014)48 _{compared and evaluated the}

influence of different lengths of implants on stress upon bone in

mandibular posterior and concluded that under static horizontal loading

conditions, shorter implants transfer more stresses to the surrounding

bone and under static vertical loading they transmit lesser load to the

surrounding bone.

31

Finite element analysis is a typical work out of the method involves

dividing the domain of the problem into a collection of subdomains, with each

subdomain represented by a set of element equations to the original problem,

followed by 2 systematically recombining all sets of element equations into a

global system of equations for the final calculation. The global system of

equations has known solution techniques, and can be calculated from the initial

values of the original problem to obtain a numerical answer. In addition to

information about element and nodes, this model also contains information about

material and other properties, loading and boundary conditions.

Here modeling software ‘SOLIDWORKS-2018’ was used which is a solid modeling computer aided design (CAD) and computer aided engineering

(CAE) computer program. The structure of the human mandible of a complete

dentulous patient was transferred from the CT Scan and was converted in an

IGES (Initial Graphics Exchange Specifications) format onto the database. Once

a structure is numerically created and material properties are assigned it can be

analyzed for stress distributions during force application using finite element

software. The finite element software used in this study was ‘ANSYS 18.2’. The global (x, y, z directional axes) combination of the absolute values squared of all

stresses-is known as Von Mises stresses.

Finite element analysis is a numerical method based on the principle

of dividing a structure into finite number of small elements that are inter

connected with each other at the corner points or nodes having three degrees of

32

unique elastic properties (Poisson's ratio and modulus of elasticity) to represent

the materials modelled and for each elements, its mechanical behavior can be

written as a function of displacement of the nodes. These nodes are submitted to

certain loading conditions, resulting in behavior of the model similar to the

structures it represents. When a computer analysis is performed, a system of

simultaneous equations can be solved to relate all forces and displacements at

the nodes. From this stresses and stress contours can be established in each

element and thus for the whole body. This method has gained increased usage in

biomechanical disciplines including orthopedic, cardiac and dental mechanics.

SAMPLING:

Sample size of each group: 4

a. Total sample size of the study: 20

b. Scientific basis of sample size used in the study : n = 𝑍

2 _𝑆2

𝑑2

n = Sample size = 20

Z = Value associated with confidence

S = Standard deviation of Mean 2.3 *

d = Absolute precision 1.2

* With reference to the study conducted by Raquel correia de Medeiros, eder alberto

sigua, Sergio olate, Pablo Navarro, in 2016

Formula → Patrikson S ; In textbook of Public Health and community medicine , Ist

Ed , 2009

Sample size = 20

Here 15 is the total sample size

c. Sampling Technique: Not applicable.

d. Inclusion criteria:

33

Group II: 3D mandible with Angle fracture with 2.5mm 2-hole

titanium plate with gap with 6mm screws

Group III: 3D mandible with Angle fracture with 2.5mm 4-hole

titanium plate with 6mm screws

Group IV: 3D mandible with Angle fracture with 2.5mm 6-hole

titanium plate with 6mm screws.

Group V: 3D mandible with Angle fracture with 2.5mm 2-hole

titanium plate with gap on the External Oblique Ridge and 4-hole titanium

plate with gap with 6mm screws on the Lateral surface.

e. Exclusion criteria: Damaged specimen

System configuration

A computer with the following system configuration was used

➢ Windows edition- Windows 8, service pack 2

➢ Processor- Intel® Core ™ i7 CPU M 430@ 2.27GHz 2.26GHz

➢ RAM: 4.00GB

➢ 64-Bit operating system

The geometric model of mandibular body was constructed based on

the measurements of a human dentulous mandible derived from a CT Scan.

Geometry of the Mandible

The dentulous section of the mandibl