Need of the Study

RAJIV GANDHI UNIVERSITY OF HEALTH SCIENCES, BANGALORE, KARNATAKAANNEXURE –IIPROFORMA FOR REGISTRATION OF SUBJECTS FOR DISSERTATION1 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 – 5600602 NAME OF THE RAJA RAJESWARI DENTAL INSTITUTION COLLEGE AND HOSPITAL3 COURSE OF STUDY AND MASTER OF DENTAL SUBJECT SURGERY IN ORTHODONTICS AND DENTOFACIAL ORTHOPAEDICS4 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 dentoalveolar heights.1Previous 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.1To 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 dentoalveolar region & its relationship with vertical craniofacial heights.AIMS AND OBJECTIVES OF THE STUDY :To evaluate the relationship between molar dentoalveolar 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 dentoalveolar height in subjects with small ANS-Me & wide PP- MP angle . Highest values were found with increasedANS- 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.57 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.7MATERIALS AND METHODS :7.1 SOURCE OF DATAThe 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?YesThe 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 CANDIDATE10 REMARKS OF THE GUIDE11 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 GUIDE11.3. 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 & PRINCIPAL12.2. SIGNATURE

Need of the Study

Details

Download

Copyright

We respect the copyrights and intellectual property rights of all users. All uploaded documents are either original works of the uploader or authorized works of the rightful owners.

Support