Abstract :
Background: The cephalometric evaluation of an individual case using floating norms is the contemporary approach in orthodontic diagnosis. This study aimed to evaluate the correlation of mandibular ramus to the mandibular base ratio with mandibular incisor proclination in a mixed Indian population.
Materials and Methods: A total of 100 cephalograms were selected from the archives of the department of orthodontics fulfilling inclusion and exclusion criteria.The mean age of cases studied was 17.09 ± 2.61 years, with an age range of 13–26 years. The sample comprised 47 males and 53 females.
Results: The results of this study showed that the higher incisor mandibular plane angle (IMPA) has statistically and clinically significant association with a higher ramus to mandibular base ratio in both male and female groups. The unit increase in IMPA is significantly associated with a 0.004 unit increase in the ratio of ramus to mandibular base.
Conclusions/Implications: This study concludes that the IMPA and ratio of ramus to mandibular base are the closest counterparts of each other and explains the variations in the IMPA even in the population group with similar skeletal characteristics. These two components interacts with each other to give a balanced occlusion and function.
Keyword :
Mandibular ramus-base ratio, Incisor mandibular plane angle, Cephalometrics