Paper Title
COMPARATIVE EVALUATION OF THE ALVEOLAR BONE THICKNESS IN VARIOUS SAGITTAL AND VERTICAL GROWTH PATTERNS-A RETROSPECTIVE STUDY

Abstract
Objective: This retrospective study aimed to compare the alveolar bone thickness in different sagittal and vertical skeletal patterns using lateral cephalograms. Material and methods: Treatment records of patients who had visited for their orthodontic needs were included in the study. Pre-treatment lateral cephalograms were collected from the department archives. A total of 176 samples were included in the study. The cephalograms were traced and divided into three groups based on the ANB angle as Group1:Class I (n=47)(ANB-2-4degrees) ,Group 2:Class II (n=87)(ANB> 4 degrees)and Group 3: Class III (n=42)( ANB< 2 degrees).The total samples were again divided based on the FMA angle as 1.Hypodivergent(FMA<22degrees) 2:Normodivergent(FMA-22-25degrees) 3:Hyperdivergent(FMA>25 degrees). Certain anatomical landmarks were marked on the lateral Cephalogramand the average thickness of alveolar bone in anterior maxillary and mandibular teeth were calculated. Results: The measured values of the various parameters did not show statistically significant difference amongst various classes of malocclusion in sagittal relation. With respect to the vertical jaw base divergences, in hypodivergent group the alveolar bone thickness on the palatal side of maxilla ,labial side and total(labial and lingual) mandibular alveolar thickness showed statistically significant higher values in comparison with the hyperdivergent group. Conclusion: The study concludes that there is no difference in the alveolar bone thickness in class I,II and III individuals,however the hyperdivergents have thinner alveolar bone on the palatal side of the maxilla ,labial and lingual aspect of the mandible while the hypodivergents have the thickest bone respectively. Keywords - Class 1,2,3 Hypodivergent, Normodivergent, Hyperdivergent, Alveolar Bone Thickness.