Authors
Dr. Divya Mandalaywala, Dr. Jayasankar P. Pillai
Abstract
Palatal rugae are the anatomical mucosal elevations that are seen in the anterior hard palate. Palatal rugae number and their patterns are not uniform in all individuals, they appear to vary in several population subsets. They are associated with variations in different regions of India and can aid as an additional tool in forensic identification procedures. Palatal rugae studies are being reported from different parts of India. It have been observed that qualitative and quantitative variations occur in palatal rugae among several populations subsets in India. Variations which are gender based in the palatal rugae have also been reported in the literature. This article reviews the pattern of variations seen in palatal rugae in different geographic locations in India as reported in the scientific literature. It is observed that the population in the Southern part of India has shown dominance in wavy patterns, whereas, in Northern and central India, the straight pattern was more common. Rugae patterns are considered as important anatomic markers in forensic human identification, large-scale multi-centric research is required to validate palatal rugae features in discriminating population (groups) in India. Thus in situations of mass disaster, the soft tissue component like rugae may be an addendum to the dental features in identifying human remains. Keywords: Geographical Variations, Palatal Rugae, Population Variation, Rugoscopy, Forensic Human Identification
Introduction
India is a land of diversity known for its variety of cultures, religions, and languages. As we move from north to south and west to east we find differences in ethnicity, secularity, heritage, and experience. Geographical diversity in India is well known across the world. Variations and diversities exist all along with the country. Considering the aspects of dentistry, an anterior third of the hard palate has a significant anatomic landmark, palatal rugae which have noticeable anatomic variations among various geographical population groups (Byatnal et al., 2014).
Palatal rugae are defined as irregular and non-identical mucosal elevations that are seen on the anterior one-third of the palate. They run in a transverse direction on either side of the mid palatine raphe (Banker et al., 2016). They are protected by lips, a buccal pad of fat, and teeth (Nanci, 2003). The number and patterns of palatal rugae vary in all individuals and also in various population subsets. ‘Palatoscopy or Rugoscopy term is used for studying palatal rugae which were first proposed by Trobo Hermosa, a Spanish investigator.
The rugae patterns are relatively unique in an individual and are known to be stable throughout the lifetime after the completion of growth. They retain their anatomic details even in the burn victims and during taphonomic decompositions to a certain extent (Muthusubramanian et al., 2005). Thus, they can be used for successful post-mortem identification provided there is a pre-existing antemortem record. In orthodontic treatments, the position of the rugae changes after the maxillary expansion, while the shape and number remain unchanged (Shailaja et al., 2018). However, the stability of the palatal rugae during and after that orthodontic treatment remains a topic of debate, especially when applied under a forensic context (Deepak et al., 2014). There are several studies done on palatal rugae patterns in the Indian population from different states. The review of the literature in this area is done and after compiling the results from those studies, conclusions have been drawn in this article.
Classification of the Palatal Rugae
The Palatal rugae classification which is widely accepted was given by Thomas and Kotze in the year 1983. They classified rugae based on unification pattern, length, shape and direction. Individual rugae length is measured transversely from its start point at the mid-palatine raphe to its endpoint. Primary rugae: 5–10 mm, Secondary rugae: 3–5 mm, Fragmentary rugae: <3 mm. According to shape, they are classified as Straight - terminates in the straight line; Curved- has a crescent shape and a gradual curve; wavy- serpentine shape of rugae; Circular- continuous ring formation. The direction of rugae is seen by the angle formed between a line joining origin and the termination of rugae concerning the mid- palatine raphe. Forward-rugae have positive angles in respect to MPR; Backwards-angles are negative with respect to MPR; Horizontal- if the angle is zero to MPR; Perpendicular- the rugae that run parallel to MPR. The term “Unification” is used when the two rugae join at their origin or insertion. When two rugae begin from the same origin but bifurcate transversely are called Diverging rugae; whereas, converging are the ones in which rugae with different origins joins on their lateral positions (Pillai et al., 2016).
The palatal rugae, in most of the studies, were analyzed using the dental models (Indira et al., 2012).
The application of advanced digital technologies like digital photographs of the models and 3D digital scanning of dental models are also being tried to analyze rugAe patterns (Santos et al., 2011; Mohammed et al., 2013; Bavaresco et al., 2020; Taneva et al., 2015).
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How to cite this article?
| APA Style | Mandalaywala, D., & Pillai, J. P. (2022). Variations in the Palatal Rugae Patterns in Indian Populations – A Need for a Multi-Centric or Multi-Regional Study under Forensic Context. Academic Journal of Anthropological Studies, 5(1), 29–34. |
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