Need of the Study
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RAJIV GANDHI UNIVERSITY OF HEALTH SCIENCES, BANGALORE, KARNATAKA
ANNEXURE –II
PROFORMA FOR REGISTRATION OF SUBJECTS FOR DISSERTATION
1 NAME OF THE Dr. KAVITHA.T, CANDIDATE POST GRADUATE AND ADDRESS STUDENT, DEPARTMENT OF ORTHODONTICS AND DENTOFACIAL ORTHOPAEDICS , RAJA RAJESWARI DENTAL COLLEGE AND HOSPITAL, MYSORE ROAD, BANGALORE – 560060
2 NAME OF THE RAJA RAJESWARI DENTAL INSTITUTION COLLEGE AND HOSPITAL
3 COURSE OF STUDY AND MASTER OF DENTAL SUBJECT SURGERY IN ORTHODONTICS AND DENTOFACIAL ORTHOPAEDICS
4 DATE OF ADMISSION TO 18 APRIL 2010 THE COLLEGE 5 TITLE OF THE TOPIC :
EVALUATION OF RELATIONSHIP BETWEEN
POSTERIOR DENTOALVEOLAR HEIGHT AND
ANTERIOR CRANIOFACIAL HEIGHT. 6 BRIEF RESUME OF THE INTENDED WORK :
6.1 NEED OF THE STUDY :
During growth and development of face,
compensatory changes in the
path of eruption of teeth tends to bring out positional changes
between the jaws, which results in short, normal or long face.
Extreme vertical facial heights are often
accompanied by an abnormal vertical development of the
posterior dento- alveolar heights.1
Previous studies were carried out to evaluate the
variations in maxillary & mandibular molar and incisor vertical
dimensions .2,3 The relationship between dento-alveolar height
with respect to cranio facial height is still a matter of debate.1
To approach proper diagnosis , treatment plan & to
obtain expected result with ultimate stability, it is essential for
orthodontist to have knowledge regarding the relationship
between posterior dento-alveolar height & vertical cranio facial
component.
Present study is designed to evaluate the compensatory dento alveolar changes in posterior dento- alveolar region & its relationship with vertical craniofacial heights.
AIMS AND OBJECTIVES OF THE STUDY :
To evaluate the relationship between molar dento- alveolar heights in relation to craniofacial height in average, vertical and horizontal facial patterns.
6.2 REVIEW OF LITERATURE :
a. Robert Martina et al (Angle Orthodontist 2005),
analysed the hypothesis stating that molar dento –alveolar
heights are positively related to vertical cranio facial
features. They found lowest values of molar dento-
alveolar height in subjects with small ANS-Me & wide
PP- MP angle . Highest values were found with increased
ANS- Me & PP- MP and lowest values of molar dento alveolar height was seen in marked divergence of jaws.1
b. Bjork et al (Am.J orthod October 1972 ),Using Implants
as reference point Bjork studied the compensatory
changes in the path of eruption & positional changes in
the jaw. He found that if dent- alveolar compensation
were insufficient or do not occur, it resulted in
defective occlusion and space anomalies.2
c. Nahoum HI et al (Am J Orthod 1972), examined
characteristic & morphological variants in long face and
identified specific site of dysplasia. They were concerned
with role played by dento-alveolar height in long face
with open bite. They found occlusal plane larger in open
bite subjects in relation to S-N Plane.3
d. Nahoum HI et al (Am.J.orthod 1977), They found most
long face are deficient in growth of upper face & posterior
face. Some variants who had adequate posterior face
height had a compensatory increase in lower anterior face height .4
e. Beckmann S.H et al (Am J orthod ,May 1998), Studied
the cephalometric relationship between lower face height
and structure of the fronto alveolar & basal bone . They
concluded that long face subjects have a larger mandibular
alveolar height, which is more associated with narrow
shaped symphysis.5
7 f. Betzen –Berger et al(TheAngle
orthodontist1999),Observed Dento- skeletal morphology
in children who were having high angle Mandibular Plane
(hyperdivergent). They found that dento –alveolar
compensation was accomplished by increase in maxillary
and mandibular anterior alveolar height , and decrease in
maxillary and mandibular posterior alveolar height.6
g. Janson G .R.P et al (Am J orthod October1994),
Evaluated maxillary and mandibular molar & incisor
vertical dimension in subjects who had excess, short and
normal lower anterior facial height in relation to upper anterior facial height. Dento alveolar height were found
to be significantly different between short, normal, excess
lower anterior facial height.7
MATERIALS AND METHODS :
7.1 SOURCE OF DATA
The study sample consists of pre-treatment lateral cephalograms of 150 patients who visit Department of
Orthodontics and Dentofacial Orthopaedics, Raja Rajeswari
Dental college, Mysore road , Bangalore. The sample will be selected according to the following criteria.
INCLUSION CRITERIA :
1. Complete permanent dentition (with exception of 3rd
molar)
2. An age group 15- 25yrs.
EXCLUSION CRITERIA : 1. Previous orthodontic treatment .
2. Unilateral or bilateral posterior cross bite .
3. Missing teeth.
4. Periodontal diseases.
5. Extensive dental restoration or crown.
6. Mandibular asymmetry.
7. Dental anomaly with respect to molars.
PROCEDURE:
1. Lateral cephalograms are selected.
2. Identification of landmarks and tracing of the
cephalogram is done by a single operator.
3. SN –MP angle is measured and is used as a reference to
divide the sample
into three groups .
a. Average growth pattern . (17º-28º).
b. Horizontal growth pattern.( <17º).
c. Vertical growth pattern.(>28º).
CEPHALOMETRIC ANALYSIS: The following landmarks and reference planes will be used in
the study.
FIGURE 1: Skeletal landmarks, lines, and angular measurements used for
cephalometric analysis.
Angular measurements :
(1) SN-MP: the angle between the SN plane and MP.
(2) SN-PP: the angle between the SN plane and PP.
(3) PP-MP: the angle between PP and MP.
FIGURE 2: skeletal landmarks, lines and vertical measurements used
for cephalometric analysis. Vertical measurements:
(1) MxMDH: maxillary molar dentoalveolar height
-the distance between the mesiobuccal cusp tip of the
upper first molar and
the palatal plane along the long axis of the molar.
(2) MdMD: mandibular molar dentoalveolar height
- the distance between the mesiobuccal cusp tip of the lower
first molar and
the lower border of the mandible along the long axis of
the molar.
(3) S-Go: Posterior facial height
-the distance between the S point and the Go point.
(4) Na-Me : Anterior facial height
- the distance between the Na point and the Me point.
(5) Ar-Go: Ramus length
- the distance between the Ar point and the Go point.
( 6) Na-ANS: anterior upper facial height
-the distance between the Na point and the ANS point.
( 7) ANS-Me: anterior lower facial height
-the distance between the ANS point and the Me point. FIGURE 3: skeletal landmarks, lines and linear measurements
used for
cephalometric analysis.
Linear measurements:
(1) Palatal plane(PP): a line that connects ANS to PNS.
(2) Mandibular plane(MP): a line that connects Go to Me.
(3) Na-S line: a line that Na to S.
Recording of the data:
Each lateral cephalogram will be manually traced by the same
operator.
Data analysis:
Data will be analysed with conventional descriptive statistics
for comparing the posterior dento-alveolar height with
anterior craniofacial height in all the three groups i.e vertical,
average, and horizontal growth patterns. Data will be tested
by means of Kalmogorov-smirnov test.
8 7.2 DOES THE STUDY REQUIRE ANY INVESTIGATION OR INTERVENTION TO BE CONDUCTED ON
PATIENTS OR OTHER HUMANS, ANIMALS? IF SO
PLEASE DESCRIBE BRIEFLY?
Yes
The Patients are subjected to lateral cephlogram.
7.3 HAS ETHICAL CLEARANCE BEEN OBTAINED
FROM YOUR INSTITUTION IN CASE OF 7.3?
Yes.
Ethical Clearance Certificate is attached.
LIST OF REFERENCES :
1. Robert Martina et al. Molar dentoalveolar and craniofacial heights. Angle Orthod 2005;75:974-976.
2. Bjork A . Facial development and tooth eruption. An implant study at the age of puberty. Am J Orthod. 1972;62:339-383.
3. Nahoum HI, Horowitz SL, Benedicto EA. Varieties of anterior open bite. Am J Orthod. 1972;61:486-492.
4. Nahhoum HI. Vertical proportions: a guide for prognosis and treatment in anterior open-bite. Am J Orthod. 1977;72:128–146.
5. Beckmann SH, Kuteirt RB, Prahl-Andersen B, Segner D, The RPS, Tuinzing DB. Alveolar and skeletal dimensions associate with lower face height. Am J Orthod. 1998;113:498–506.
6. Betzenberger DO, Ruf SA, Pancherz HA. The compensatory mechanism in high-angle malocclusion: a comparison of subjects in mixed and permanent dentition. Angle Orthod. 1999;69:27–32.
7. Janson GRP, Metaxas A, Woodside DG. Variation in maxillary and mandibular molar and incisor vertical dimension in 12-years-old subjects with excess, normal and short lower anterior face height. Am J Orthod. 1994;106:409–418.
9 SIGNATURE OF THE CANDIDATE
10 REMARKS OF THE GUIDE
11 11.1. NAME & Prof. Dr. RAJKUMAR S. DESIGNATION ALLE, M.D.S, DNB OF GUIDE PROFESSOR AND HEAD, DEPARTMENT OF ORTHODONTICS AND DENTOFACIAL ORTHOPAEDICS, RAJA RAJESWARI DENTAL COLLEGE AND HOSPITAL, BANGALORE.
11.2 SIGNATURE OF GUIDE
11.3. CO-GUIDE (If any)
11.4. SIGNATURE
Prof. Dr. RAJKUMAR S. 11.5 HEAD OF THE ALLE, M.D.S, DNB DEPARTMENT PROFESSOR AND HEAD, DEPARTMENT OF ORTHODONTICS AND DENTOFACIAL ORTHOPAEDICS, RAJA RAJESWARI DENTAL COLLEGE AND HOSPITAL, BANGALORE.
11.6. SIGNATURE 12 12.1. REMARKS OF THE CHAIRMAN & PRINCIPAL
12.2. SIGNATURE