RAJIV GANDHI UNIVERSITY OF HEALTH SCIENCES, KARNATAKA BANGALORE.
ANNEXURE II
PROFORMA FOR REGISTRATION OF SUBJECT FOR DISSERTATION
1 NAME OF THE DR. TSERING CHOEKEY . CANDIDATE AND G.P. O BOX NO: 3745 AGARTHI MARG, ADDRESS NARAYANGOPAL CHOWK, MAHARAJGUNJ, KATHMANDU NEPAL
M.S. RAMAIAH DENTAL COLLEGE AND 2 NAME OF THE HOSPITAL, MSRIT POST, MSRIT NAGAR, . INSTITUTION BANGALORE,KARNATAKA-560054
3 COURSE OF STUDY AND MASTER OF DENTAL SURGERY (MDS) . SUBJECT IN ORTHODONTICS & DENTOFACIAL ORTHOPEDICS 4 DATE OF ADMISSION TO 25 APRIL 2012 . COURSE 5 TITLE OF THE TOPIC ESTABLISHING CEPHALOMETRIC . NORMS USING STEINER'S AND COGS (CEPHALOMETRIC FOR ORTHOGNATHIC SURGERY) ANALYSIS IN INDIAN
IMMIGRANT TIBETAN POPULATION : A
CROSS-SECTIONAL STUDY Brief resume of the intended work
6. 6.1 Need for the study
Cephalometric analysis is the study of dental and skeletal relationships in the head. It is used to evaluate relationships , (both horizontal and vertical) of 5 major components of the face : the cranial base the maxilla ,the mandible the maxillary and mandibular dentoalveolus It is frequently used by dentists, often orthodontist in particular as a treatment planning tool.
According to research of Cotton, Takano and Wong, Haralabakis, Altemus and Kotak , normal cephalometric measurement of one group cannot be considered normal for other racial groups. So therefore, it is important to develop standards for different population groups.1,2,3,4.
Approximately 1,28014 Tibetans are in exile and 94,203 Tibetans are residing in India.5 They are different ethnically with unique facial and physical characteristics, distinct language and culture of their own.Thus, as a clinician of the same origin, there is need to set up a standard cephalometric norms for the Tibetan population using Steiner's analysis and COGS analysis inorder to facilitate the orthodontic and surgical diagnosis and treatment planning . 6.2 Review of literature The first cephalometric analysis developed was Down's analysis based on a reference group of
25 untreated adolescent whites selected because of their ideal dental occlusions. Later Dr
Cecil .C Steiner in 1950s developed an analysis with extreme of selectivity in establishing a reference standard called it Steiner's analysis. But it has been largely replaced by newer standards with different analysis.6
One of new analysis called COGS (Cephalometric for orthognathic surgery) analysis, was developed by Burstone CJ et al. (1978) for evaluation of orthognathic surgical patients The standards were based on a sample of 16 females and 14 males, obtained from the Child
Research Council in Colorado7
Legan and Burstone (1980) developed a soft tissue cephalometeric analysis for surgical- orthodontic patients, to complement the previously reported dentoskeletal analysis. Burstone established norms used in this analysis were derived from a population of 40 white adults(20 men and 20 women)8
A cephalometric evaluation of Mexican Americans was done using the Down's and Steiner's
Analyses by Carlos J Garcia with sample size of 25 girls and 34 boys of Mexican American. He found that Mexican American sample was more protrusive than Caucasian sample.9
A study done by Gleis Ruth, Brezniak Naphtali and Lieberman Myron, in which Israeli cephalometric standards was compared to Downs and Steiner analyses. Sample of 40 young
Israeli adolescents , 18 males and 22 females were examined cephalometrically and showed more convex profile, and more protrusive incisors, with the tendency for a more retrusive mandible.10
Nabanita Baruah and Mitali Bora had done a cephalometeric study of 70 Assamese young adults
(35 male and 35 female )in 2009, within age of 18-25 years by means of Steiner's analysis concluded that in comparison to the Caucasian samples in the Assamese samples were the anteroposterior position of the apical base of the maxilla and mandible in relation to anterior cranial base was more anteriorly placed or prognathic.11
In 2011, another study was done by H.A Mohammed et al., to set cephalometric norms for
Malaysian Malay by Steiner's analysis. A sample of 60 Malaysian Malay (30 male and 30 female) were taken and the result of this study showed that their maxilla and mandible were set more forward and also showed bimaxillary dental protrusion compared to Caucasian.12
Alcade RE et al. studied lateral cephalometric standards of normal Japanese adults, using COGS analysis.Cephalometric radiographs of 217 Japanese adults were analyzed.They found out that statistically significant which Japanese adults had shorter maxilla, larger upper anterior face height, and lower posterior dental height than COGS's white sample. Soft tissue analysis of the
Japanese subjects showed a retrognathic maxilla and mandible when compared with the white adult standards.13
A study conducted by Sahar F.AlBarakati, Laila F.Baidas to set orthognathic surgical norms for
Saudi adults. Sixty two lateral cephalometric radiographs (31 males and 31 females) age range
22-24 years were analysed and showed that Saudi male had an increased cranial base length, mandible lied more posterior to maxilla, increased mandibular plane angle and less prominent chin, shorter maxillary length and also less proclination of lower incisors compared to those of
European Americans.14
6.3 Objectives of the study To establish cephalometric norms for Tibetan resident in India by using Steiner's and
COGS analysis.
To compare Steiner's cephalometric norms of Tibetan population with Steiner's standard
norms.
To compare COGS cephalometric norms of Tibetan population with those of COGS
standard norms.
Material and methods 7.1 Source of data Source:A study will be conducted in subjects aged 17-30 years of Tibetan population in India. The data for this study will be obtained from young Tibetans who are studying in Bangalore and some from Bylakuppe Tibetan Settlement in Kushalnagar.
Materials: The sample for this study will consist of 50 lateral cephalometric radiographs. Kodak X-ray film (8x10 inches). Acetate matt paper. Mathematical drawing instruments. 3H pencil.
Method of data collection: Subject selection criteria: INCLUSION CRITERIA 1. Tibetan Origin: Both parents of each subject should be from same ethnic group without any inter racial marriage atleast for two generations. 2. Have a pleasing profile. 3. Individuals with no history of orthodontic treatment. 4. Having Class I molar and canine relationship in proper intercuspation, acceptable overjet and overbite and mild-spacing / crowding (not more than 3mm).
EXCLUSION CRITERIA 1. Subjects below age of 17 and above 30 will be excluded. 2. Subjects with any congenital abnormality and facial trauma. 3. Medically compromised patients.
SAMPLE SIZE AND DESIGN Sample size:50 From the literature review, in a study Mohammad H.A et al. has been observed that the average angular measurement SNB was 81.20 +_2.86 among Malaysian population and it was 800 among Caucasian population. With the help of nMaster software developed by Biostatistics department, Vellore Medical College, in the present study assuming Tibetan population will also get similar result with precision of 95% confidence and 80% power we need minimum of 50 subjects.
Study design: A cross sectional study.
METHDOLOGY Lateral cephalograms of each individual will be taken or collected using Planmeca PM 2002 CC Proline Pan/Ceph manufactured by Planmecca with voltage of 70KV and current of 10 MA are used to obtain the lateral head film. The exposure time is 1.2 seconds. The head of the patient will be guided in the cephalostat and the natural head posture is obtained by making the patient look straight ahead with FH plane parallel to the floor.The position will be stabilized with the help of ear rods. The distance from the tube to the patient will be standardized at 5 feet. The cephalograms were all traced on acetated matt paper(8x10 inches) using 3H pencil. All the required hard and soft tissue landmarks will be marked and various angles and linear measurements will be analysed in accordance to the Steiner's and COGS analysis which is also explained in flow chart comparison comparison
. STATISTICAL ANALYSIS: Descriptive statistics of angular and linear measurements(for eg: SNB, SNA) will be analysed expressed in terms of mean and standard deviation. Normal t test for single mean comparison will be used to angular and linear measurements of Tibetan population compared to standard known value of Caucasians.
7.2 Does the study require any investigation or interventions to be conducted on patients or other humans or animals , if so please describe? Yes, it is a cross sectional study in which lateral cephalometric radiographs of each individual will be taken with consent.
7.3 Has ethical clearance been obtained from your institution in case of 7.4 ? Yes
8. List of references 1. Cotton W.N, TakanoW.S, Wong W.W.The Downs analysis applied to three other ethic groups. Angle Orthod.1951;21:213-220.
2. Haralabakis H. Familial resemblances in craniofacial Greek families. Abst. in A.J Orthod.1954
3. Altemus LA. A comparison of cephalofacial relationships. Angle Orthod.1960;30(4):223-240.
4. Kotak V.B. Cephalometric evaluation of Indian girls with neutral occlusion.J Indian Dent Assoc. 1964;30:183-97.
5. Planning Commission of Central Tibetan Administration.Demographic Survey of Tibetans in exile 2009.
6. Profitt R.William et al. Contemporary Orthodontics.Orthodontic Diagnosis.4th ed.St Louis:Mosby;2007;201-207.
7. Burstone CJ, James RB, Legan H, Murphy GA, Norton LA. Cephalometric for Orthognathic Surgery. J Oral Sur.1978;36(4):269-277.
8. Burstone CJ, Legan HL. Soft tissue cephalometric analysis for orthognathic surgery. J Oral Surg.1980;38(10):744-755.
9. Carlos J Garcia. Cephalometric Evaluation of Mexican Americans using the Downs and
Steiner's analyses.Am J Orthod.1975;68(1):67-74.
10. Gleis Ruth, Brezniak Naphtali and Lieberman Myron. Israeli cephalometric standards
compared to Downs and Steiner analyses. Angle Orthod.1990;60(1):35-40.
11. Baruah Nabanita, Bora Mitali. Cephalometric evaluation based on the Steiner's analysis on young adults of Assam. J Ind Orthod Soc.Jan-Mar2009;43(1):17-22.
12. H.A Mohammed, M.I Abu Hassan, S.F Hussain. Cephalometric evaluation for
Malaysian Malay by Steiner's Analysis.Scientific Research and Essays. Feb 2011;6(3):627-
634. 13. Alcade RE et al. Cephalometric norms in Japanese adults. J Oral Maxillofac Surg 1998;
56(2):129-34.
14. Albarakati F.Sahar et al.Orthognathic surgical norms for a sample of Saudi adults.The
Saudi Dental Journal 2010;22:133-139. CONSENT FORM
I have been informed about the procedures of the study. I understand my participation is voluntary and that I am free to withdraw any time during the study without giving any reason. I have been provided ample time to ask questions and I have clarified to my satisfaction. I, ………………………………...... the undersigned, give my consent to be a participant of this study.
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