Quantitative and Transverse Changes in the Position of Palatal Rugae after Palatal Expansion

Background: Palatal rugae are irregular and non-identical mucosal elevations seen on anterior third of palate. They are arranged in transverse direction on either side of Median Palatine Raphe [MPR]. Though they are the most stable anatomical structures in the oral cavity, certain conditions like orthodontic treatment contribute to some amount of variations in their pattern qualitatively. During literature review, we found scarcity of articles related to quantitative changes in rugae patterns, before and after palatal expansion. The aim of this study was to compare the number of rugae and its positional changes using before and after Semi Rapid Maxillary Expansion (SRME) study models. Materials and Methods: Seventy nine pairs of pre and post expansion casts showing finer details of palatal rugae from 37 males and 42 females in the age group of 10 to 12 years were selected for this study. The number of rugae and the distance between the median points of the first and the last two rugae on either side of MPR were noted. The data collected were statistically analyzed using SPSS program Results: Descriptive statistics mean and standard deviation were performed for study group before and after treatment at T0 and T1. There was no statistically significant change in number of rugae in the right side but significant differences were noted in the distance between medial points of first two rugae and distance between last two rugae. There was statistically no significant change in any of the variables when the data from male and female samples were compared. Conclusion: During maxillary expansion, there is stability of palatal rugae with respect to its number but not with respect to its position. There is significantly more separation of the medial ends of the opposing rugae on either side of MPR in the anterior region than on the posterior.