Quantitative and qualitative analysis of palatal rugae patterns in Gujarati population: A retrospective, cross-sectional study

Abstract

Introduction: Palatal rugae are irregular and nonidentical mucosal elevations seen on the anterior third of palate. They are arranged in transverse direction on either side of the median palatine raphe (MPR) and are protected from high temperature and trauma because of their rational position in the oral cavity. Their number and patterns are not uniform in all the individuals, and they appear to vary in different population subsets. The study of palatal rugae is termed as “Rugoscopy” or “Palatoscopy”, and it finds its application in various fields such as anthropology, orthodontics, forensic sciences; including forensic odonto-stomatology. Aim: The aim of this study was to evaluate the quantitative and qualitative parameters of palatal rugae using pre-orthodontic study models of Gujarati samples. Objectives: (1) To identify the predominant palatal arch forms in the study samples. (2) To evaluate and correlate the rugae count in both male and female samples with the different palatal arch forms. (3) To assess the symmetry and/or asymmetry in rugae count between the right and left side. (4) To analyze and correlate the qualitative characters such as size, shape, direction, and unification in male and female study samples. Materials and Methods: One hundred pre-orthodontic maxillary dental stone casts of patients with an age range of 17–25 years were selected. The outlines of the rugae were traced using microtip graphite pencil and examined using magnifying glass for different patterns. The quantity and quality of rugae patterns were recorded according to Thomas et al. classification and the data were statistically analyzed by the statistician using SPSS program. Results: Overall, 962 rugae were observed in the study sample. The mean rugae count was 9.86 in males and 9.38 in females. The left side rugae count was more than the right side in both the sexes and it was not statistically significant. Fifty-six percent of the samples showed asymmetry in rugae count between the right and left. Class B palatal arch form was the most common type in the study samples. The number of primary rugae count was more in both the sexes. The distribution of straight (40.2%) and curved (40.4%) types of rugae were almost equal in males but in females, the straight rugae pattern (42.2%) was more than the curved (36.9%), followed by wavy and circular. Of 962 rugae, 36.4% were of horizontal type followed by forward (33.4%) and backward (29.2%). About 1 % of rugae showed perpendicular pattern and only 9.25% showed unification pattern and the divergent type of unification was more common than the convergent type. Conclusion: There is no gender discrimination in relation to any of the metric or non-metric parameters of the palatal rugae in this study samples. No two samples showed similarity in the distribution of palatal rugae patterns. The straight and horizontal rugae distributions were predominant in our Gujarati Study samples.