Morphological patterns of the palatal rugae: A review

Background: Palatal rugae are asymmetric ridges of connective tissue located behind the incisive papilla over the anterior hard palate. They serve as stable superimposition landmarks to assess tooth movement in orthodontics and as identification aids in forensic odontology. However, the stability of palatal rugae remains controversial. This review aimed to describe the genetic, growth, and environmental factors that may influence the palatal rugae patterns. A broad search of PubMed and ScienceDirect databases was conducted. A total of 193 articles were identified, of which 73 met the selection criteria. Data were extracted into a table that presented the details of the study, sample description, and changes in the palatal rugae patterns. Highlight: There were conflicting results regarding sexual dimorphism and population characterization of the palatal rugae patterns. All rugae showed positional changes, increased lengths, and lower numbers, but no significant shape changes with growth. The lengths, numbers, and positions of the rugae were affected by orthodontic treatment, especially their lateral points, but their individual characteristics did not change. Conclusion: The diversity in rugae patterns and their potential for sex discrimination among different populations showed differing results due to individual variations and the complex influence of genetic, growth, and environmental factors on their morphology. (C) 2020 Japanese Association for Oral Biology. Published by Elsevier B.V. All rights reserved.