Introduction
Palatal rugea, termed as“plicae palatinaetransversae” and “rugae palatine” denote to the elevations on the frontal part of the palatalmucosa, each side of the median palatal raphe and beyond the incisive papilla. According to Glossary of Prosthodontics rugae are anatomical folds or wrinkles usually the irregular fibrous connective tissue located on the frontal third of the palate. Palatoscopy or palatal rugoscopy is the study of palatal rugae in order to establish a person’s identity. Palatoscopy gives a fairly valid conclusions pertaining to person’s identification. As human identification is necessary in all social and legal aspects.1
Development of rugae
Palatine rugae develops during third month of intrauterine life its growth is controlled by epithelial mesenchymal interactions. First rugae are developed in embryo of 32 mm following incisive papilla in prenatal stage. Once papillae are formed size may change as palate grows , but shape remains the same.2
History2, 3
Classification of palatal rugae 2, 3, 4
Goria in 1911 developed first system of categorizing. He categorized rugae pattern into bilateral
It is distinguished into two types ie both primitive and more developed.
Lysell’ classification in 1955 was most important and used widely in research Rugae are categorized into three categories
Primary 5 mm or more
Secondary 3 to 5 mm
Fragmentary 2 to 3 mm
Rugae smaller than 2 mm are disregarded
Trobo in 1932 categorized into two groups
Rugae Type
Table 1
|
Classification |
Rugae type |
|
Type A |
Point |
|
Type B |
Line |
|
Type C |
Curve |
|
Type D |
Angle |
|
Type E |
Sinuous |
|
Type F |
Circle |
Methods to Collect Palatal Rugae5, 6
Impressions are being taken using alginate as impression material Impresssion of palatal arch was prepared and dental stone was poured. Tracing of the rugae pattern was done with the help of sharp 5 HB graphite pencil under light . Now with the help of magnifying lens casts were explored thoroughly and further rugae are classified according to classification
Task of Palatal rugae3
To ease food transportation through oral cavity
Because of gustatory and tactile receptors there is presence of taste.
Divergence of rugae pattern according to ethnicity
There seems to be compelling linkage between rugae forms and ethnicity. Kapali et al. calculated the palatal rugae markings in Australian Aborigines and whites and found that number of primary rugae were higher in Australian than in whites.
Burn cases
Muthusubramanian et al. surveyedthe demarcation of palatine rugae preservation and used for an descriptive tool in burn victims and cadavers, thus helping in solving forensiccases decomposed and incinerated bodies.
Forensic identification
Jumping into conclusion regarding person’s identity can bea difficult task in various cases of plane crashes accidents, terrorist attacks or massdisaster situations. Allen et al. in 1889 suggested the application of palatal rugae markings for personal identification.
Preference of Palate over other lip prints or finger prints7
The markings of palatine rugae display racial and gender diversity as they are not subjected to obvious changes. Rugae are protected from trauma and other extreme conditions like high temperatures as they are shielded by the lips. Although in decomposed bodies lipprints and fingerprints cannot be recorded. But on the otherhandpalatal rugae are available for comparison and identification as they are least resistant to destruction.
Antemortem data can be advantageous7
As it demanding to obtain dental arch impressions from corpses arriving at Foresnsic Medicine Institute so antemortem data of victim can be compared. As experts are not familiar with dental impressions So in such cases antemortem models can be obtained from victims dentists and can be compared with postmortem images using software.
Outcome of various literature for palatoscopy
Byatnal A et al in 20146 conducted a comparative study for analyzing variations among five different populations of India and upon concluding it could not identify any special variations in diffusion of various palatal rugae markings. Thus, further studies are required by taking huge study samples.
Ramdas S et al in 20195 conducted a study for comparing and correlating Dactyloscopy and Palatoscopy with blood group from western Maharashtra population .Thus to sum up the comparison made with palatal rugae and finger print yielded no result.
Ashoka A et al in 20208 carried out a study on 200 individuals (100 males and 100 females) among Kerala population . Thus on winding up study has proved chieloscopy and palatoscopy identified the sex and identity of the individual.
Sharma P et al in 20099 conducted a study for forensic recognitation, using method of cheiloscopy and palatoscopy . On summing up it shows that not palatal rugae and lip prints are unique to an individual, but lip prints is more loyal for identification of the gender.
Asdullah M et al in 201410 studied the widespread prsence of different palatal rugae markings in a instance of Lucknow. On concluding it was found that there is a scope that exists to determine sex of an individual as well as personal identification.
Rajguru J P et al in 201411 analyzed the rugae markings in dentulous and edentulous dentition and also evaluated the association of rugae markings between genders. To sum up in the present study there is similar distribution of rugae pattern between male and female dentition while there is varied pattern between the sexes of edentulous population.
Pramanik A et al in 201912 conducted a study to check any gender difference in palatal markings pattern among subjects from Bengal in Murshidabad district. Thus, current study revealed a significant gender difference in palatal rugae markings in Murshidabad population.
Mathew SA et al in 201613 conducted a study to compare the uniqueness of rugae marking and cheiloscopy and on conclusion it was found that the sex and identity of the individual, as they remain stable over time and unique to individual.
Satish K et al in 201214 conducted a study among regarding palatal rugoscopy among Puducherry population and found that wavy pattern was most prominent followed by curved, straight, branched and circular pattern in both the genders.
Conclusion
Palatal rugae are located in the frontal half of the mouth, serves as landmark in various studies . Various studies show a huge significance between rugae forms and different ethnicity. Palatal rugae are important in forensic investigations. Antemortem records can be kept so it is responsibility of government to maintain these records for future.
