Analysis of the Morphological Characteristics of the Palatal Rugae for Three-Dimensional Superimposition of Digital Models in Korean Subjects

Abstract

Objective. The aim of this study was to evaluate the morphological characteristics of the palatal rugae in Korean subjects to determine whether the palatal rugae can be used as an appropriate reference area for three-dimensional digital model superimpositions. Materials and Methods. In total, 343 patients (110 men, 233 women; mean age, 25.6±8.2 years) who had a digital model taken at their initial visit were included, and the numbers and types of right and left palatal rugae were investigated according to the primary, secondary, and fragmentary rugae. Finally, the differences in the positions of the third primary ruga were investigated according to the presence of additional rugae posterior to the third primary ruga. Results. The number of primary palatal rugae ranged from one to six, with 43.5% of the subjects having three primary rugae and 36.1% having four primary rugae; there were no significant differences between sexes. Except for the fragment rugae, the numbers of primary and secondary rugae were not significantly different between the left and right sides. The third primary ruga was located more significantly anteriorly when there was an additional ruga posterior to the third primary ruga (P < 0.001). Conclusions. The numbers of the palatal rugae vary greatly among individuals, and this affects the anteroposterior position of the third primary ruga. When the third primary ruga is located anteriorly, care should be taken when using it as a reference area for superimposition with a digital model before and after orthodontic treatment.