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RAJIV GANDHI UNIVERSITY OF
HEALTH SCIENCES,
BANGALORE, KARNATAKA
ANNEXURE - II
2013-14
PROFORMA FOR THE REGISTRATION
OF
SUBJECT FOR DISSERTATION
BY:
Dr. ASHRITHA REDDY BORA
Postgraduate Student
DEPARTMENT OF ORTHODONTICS AND
DENTOFACIAL ORTHOPAEDICS
Krishnadevaraya College of Dental Sciences and Hospital,
Bangalore – 562 157
RAJIV GANDHI UNIVERSITY OF HEALTH SCIENCES,
BANGALORE, KARNATAKA
Proforma for Registration of Subject for Dissertation
01.
Name of the
Candidate and
Address
(in block letters)
Dr. ASHRITHA REDDY BORA
POSTGRADUATE IN DEPARTMENT OF
ORTHODONTICS AND DENTOFACIAL
ORTHOPAEDICS
KRISHNADEVARAYA COLLEGE OF
DENTAL SCIENCES AND HOSPITAL,
KRISHNADEVARAYA NAGAR, VIA
YELAHANKA, HUNASAMARANAHALLI,
BANGALORE - 562 157
02.
Name of the
Institution
Krishnadevaraya College of Dental Sciences
and Hospital, Bangalore
03.
Course of Study
and Subject
Master of Dental Surgery in Orthodontics and
Dentofacial Orthopaedics
04.
Date of
Admission
27/05/ 2013
05.
Title of Topic
Stress distribution around the implant during
intrusion in the maxillary anterior region : A
three dimensional finite element analysis.
6. Need for the Study:
6.1: Need for the study:
Proper anchorage is one of the most crucial factors for a successful orthodontic treatment
outcome. Mini-implants have attracted great attention in recent years because of its small
size, versatility, minimal surgical invasiveness, instant loading, easy availability and low cost.
The development of a stress field incorporating the alveolar bone around the mini-implant is
reportedly correlated with mini-implant failure.1
Deep overbite is a common component of malocclusion which can be corrected by
nonsurgical treatment alternatives like molar extrusion, incisor intrusion, or a combination of
both.
Mini screw implants are especially well suited for intruding teeth because they make it
possible to apply light continuous forces of known magnitudes without producing any
reactionary reciprocal effect on posterior teeth2 and hence can diminish apical root resorption
often associated with intrusive movements.2
The purpose of this study is to analyze the stress distribution around the implant during true
intrusion in the maxillary anterior region using finite element models.
6.2: Review of literature
A finite element study was conducted to investigate the changes in stress distribution at the
supporting bone and mini screw by changing the angle and the shape of the mini screw and
the direction of force. Three types of mini screws were designed and inclined at 300 400 450
500 600 700 800 900 to the surface of two types of supporting bone. A force of 2N was applied
in three directions. The maximum stress varied at each angle according to the direction of the
applied load. They concluded that the maximum stresses observed in all analyzed types and
shapes of mini screws were under the yield stress of pure titanium and cortical bone. This
indicates that the mini screws in this study have enough strength to resist most orthodontic
loads.3
A study was conducted to analyze the stress distribution and displacement patterns that
develop in an orthodontic mini screw implant and its surrounding osseous structures for two
implant materials under horizontal and torsional loading with no osseointegration. They
concluded that the differences between the values of stress and displacement that they
obtained for two types of the mini screw were too small to be clinically significant.
Optimization of the mini screw implant composed of the titanium alloy might be achieved by
increasing the bulk of the material in the neck region. The mini screw implant can be
immediately loaded and used for group movement of teeth.4
A study was conducted to investigate the roles of bone quality, loading conditions, screw
effects, and implanted depth on the biomechanics of an orthodontic mini screw system by
using finite element analysis. A three dimensional model of bone block integrated with a mini
screw was constructed to simulate various cortex thicknesses, cancellous bone densities,
force magnitudes, and directions, screw diameters and lengths , and implanted depths of mini
screws. They concluded that screw diameter was a dominant factor for mini screw
mechanical responses. Both bone stress and screw displacement decreased with increasing
screw diameter and cortex thickness , and decreasing exposed length of the screw, force
magnitude, and oblique loading direction.5
A study was conducted to determine the stress distribution in maxillary anterior region during
true incisor intrusion using a finite element models. Soft bone and hard bone showed
significantly high stress distribution in the maxillary anterior region. They concluded that the
stress on the teeth, soft bone, and hard bone were concentrated more on and near the central
incisors as compared to lateral incisors. This was probably because the point of force
application was between the central incisors and away from the lateral incisors.1
A study was conducted to determine the biomechanical effects of exposure length of the mini
implant, the insertion angle ,and the direction of orthodontic force using a finite element
approach and factorial analysis. Twenty seven finite element models were constructed to
simulate the biomechanical response of the alveolar bone adjacent to the mini implant.
Factorial analysis was performed to investigate the comparative influence of each factor.
They concluded that increased exposure lengths resulted in higher bone stresses adjacent to
the mini implant. The percentage of the contribution of the insertion angle of the mini
implant(6.03%) was also statistically significant but much less than that of the exposure
length(82.35%). The direction of orthodontic force had no significant effect on cortical bone
stress.2
6.3: Objectives of the Study:
1. To study the stress distribution patterns of the bone and supporting structures in the
anterior maxillary region.
2. To compare the
stress distribution of bone at various angulations of the implant
placement.
7. Materials and Method:
In this study a 3D computed tomographic(CT) scan of adult maxilla will be taken.
For the study, 3 finite element models are generated. These models are the replica of the adult
human maxilla.
The models will be consisting of periodontal ligament, alveolar bone, and all the teeth except
the third molars.
Mathematical models represent the biological properties of the teeth and the periodontium.
The bracket system will be simulated is MBT metal bracket system from 3M Unitek and the
arch wire was of 19*25 stainless steel consisting of two attachments between lateral incisor
and canine bilaterally.
A mathematical model of titanium self drilling implant (DENTAURUM ) of 8 mm length and
1.2mm diameter will be inserted between the roots of lateral incisor and canine at different
angulations (750,900,1050) applying a total force of 100g each side to intrude the maxillary
anterior teeth.
The finite element models are generated and the study will be carried out using a finite
element software( ANSYS ,12.1 version )
8. Does the study require any investigation or interventions to be conducted
on patients or other humans or animals?
NO
Has ethical clearance been obtained in your institution in case of 8?
NOT APPLICABLE
List of References:
1. Ting-Shong Lin, Feng-De Tsai,Chih-Yu Chen, Li-Wen Lin. Factorial analysis of
variables affecting bone stress adjacent to the orthodontic anchorage mini implant
with finite element analysis.Am J Orthod Dentofacial Orthop2013;143:182-9
2. Sagar S Padmawar, Anup Belludi, Amit Bhardwaj, Vinay Vadvadgi, Rajiv Saini. Study of
stress distribution in maxillary anterior region during true intrusion of maxillary incisors
using finite element methodology. International Journal Of Experimental Science;JulyDecember2012;1(2):89-92 .
3. Akhirio Suzuki, Taisuke Masuda , Ichiro Takahashi, Toru Deguchi, Osamu Suzuki, Teruko
Takamo-Yamamoto. Changes in stress distribution of orthodontic mini screws and
surrounding bone evaluated by 3-dimensional finite element analysis. Am J Orthod
Dentofacial Orthop: 2011;140:e273-e280.
4. Shivani Singh, Subraya Mogra, V.Surendra Shetty, Siddarth Shetty, Pramod Philip. Three
dimensional finite element analysis of strength, stability, and stress distribution in
orthodontic anchorage: A conical , self-drilling mini screw implant system. Am J Orthod
Dentofacial Orthop 2012;141:327-36.
5. Te-Chun Liu, Chih-Han Chang, Tung-Yiu Wong, and Jia-Kuang Liu. Finite element analysis
of mini screw implants used for orthodontic
Orthop2012;141:468-76.
anchorage.Am J Orthod Dentofacial
09.
Name and Signature of the Candidate
Dr.ASHRITHA REDDY BORA
10.
11.
Remarks of the Guide
Name and Designation in Block
letters
Dr. MAHESH C M
11.1: Guide
PROFESSOR ,
DEPARTMENT OF
ORTHODONTICS AND
DENTOFACIAL ORTHOPAEDICS
KRISHNADEVARAYA COLLEGE OF
DENTAL SCIENCES, BANGALORE –
562 157
11.2: Signature
11.3: Co – Guide
Dr. MAHENDRA.S
READER,
DEPARTMENT OF
ORTHODONTICS AND
DENTOFACIAL ORTHOPAEDICS
KRISHNADEVARAYA COLLEGE OF
DENTAL SCIENCES, BANGALORE –
562 157
11.4: Signature
11.5: Head of the Department
Dr. NIKHILANAND HEGDE
PROFESSOR & H.O.D.
11.6: Signature
12.
12.1: Remarks of the Principal
12.2: Signature
ETHICAL CLEARENCE FOR DISSERTATION STUDY
Ethical clearance for dissertation study, “ STRESS DISTRIBUTION AROUND THE IMPLANT
DURING INTRUSION IN THE MAXILLARY ANTERIOR REGION : A THREE
DIMENSIONAL FINITE ELEMENT ANALYSIS”, by Dr.ASHRITHA REDDY BORA,
postgraduate student in the Department of Orthodontics & Dentofacial Orthopaedics,
Krishnadevaraya College of Dental Sciences and Hospital, under Rajiv Gandhi University of Health
Sciences, Karnataka. Ethical committee meeting was held on 31 / 10 / 2013 in the Boardroom of
Krishnadevaraya College of Dental Sciences & Hospital.
The Members discussed all the ethical issues involved
1.
2.
3.
4.
5.
Review of literature and remarks of previous studies.
Risks and expected beneficial effects.
Cost factor.
Supervision by Senior Staff members.
ICMR guidelines for Research Studies.
The members were satisfied regarding all the above Ethical issues concerned and ethical clearance
was granted for the Dissertation Study.
ETHICAL COMMITTEE MEMBERS
Sl.n
NAME & DESIGNATION
POSITION
1.
Dr. H. Nandkumar, Principal & HOD Oral Surgery
Chairman
2.
Dr. S.M. Sharath Chandra, Professor and HOD,
Conservative
3.
Mr. Gundu Rao, NGO, Social Activist
Member
4.
Mr. Mohammed Sadiq.B.A, Advocate
Member
5.
Dr. Vijay Mohan Reddy. N.H, Administrative Medical
Officer, Government General Hospital, Yelahanka
Member
6.
Dr. Srinivasa G.N, Physician, Government General
Hospital
Member
7.
Dr. Nikhilanand Hegde, HOD, Orthodontics
Member
8.
Dr. M.L.V. Prabhuji, HOD Dept of Periodontics
Member
9.
Dr. Shiva Shankar M., Prof. & HOD, Prosthodontics
Member
10.
Dr. M.B. Radhika, Prof.& HOD, Oral Pathology
Member
11.
Dr. Murali R,Professor and HOD, Public Health Dentistry
Member
12.
Dr. Deepak Vishwanath, Professor and HOD,
Pedodontics
Member
Co-chairman
SIGNATURE
13.
Dr. Vijeev Vasudevan, Professor and HOD, Oral Medicine
Member
14.
Dr. N.Srinath, Professor, Oral Surgery
Member
15.
Dr. Prabhakar, Anaesthetist
Member