Rugoscopy for establishing individuality.
Forensic identification by its nature is a multidisciplinary approach relying on positive identification methodology as well as presumptive or exclusionary methodologies which deals with proper handling and examination of dental finding. (2)
Personal identification forms an integral part of forensic science especially, when they are dealing with any crime or with mutilated bodies that have undergone damage beyond recognition. Nature has made each and every individual different in his or her own way and personal identification is the proof. (4)
Palatoscopy or palatal rugoscopy, is the name given to the study of palatal rugae in order to establish a person's identity. (20)
The use of palatal rugae was suggested as one of the method of identification in 1889 by Harrison Allen. Forensic odontology involves dentist's participation in assisting legal and criminal issues. (4)
Palatal rugae are well protected from trauma by their internal position in the head and they are insulated from heat by the lips, tongue and the buccal fat pads. (12) personal Identification is based on the rugae pattern since the palate would remain intact when most other anatomical structures are destroyed, burned or dehydrated. (12) and also in situations where there are no fingers available. It is a well established fact that anatomical position of rugae that, it retains its shape throughout life (24) and resist decomposition.
Studies have demonstrated that no two palates are alike in their configuration and that the characteristic pattern of the palate does not change as a result of growth. (30) This unique feature led us to undertake a study to establish individual identity using palatal rugae pattern.
Objectives of the study:
1) To investigate the role of rugae pattern in personal identification.
2) To determine the uniqueness of palatal rugae pattern.
3) To identify any particular pattern of rugae among family members.
4) To assess the stability of the palatal rugae pattern in the pre and post orthodontic models.
Materials and Methods:
This study was conducted at the Department of Oral Medicine and Radiology, M. R. Ambedkar Dental College and Hospital, Bangalore. The study consisted of 90 healthy subjects aged 14 years and above. Randomly selected 25 males and 25 females: 5 families (Father, Mother, Child A, Child B) 20 pairs of models (pre and post)of subjects who have completed the orthodontic treatment (10 Males, 10 Females)
Exclusion criteria: Subjects below the age of 14 years, congenital anomalies/malformations, previous orthognathic surgery, allergic to impression material, bony and soft tissue protuberances, active lesions, deformity or scars and trauma of the palate.
Alginate impression of maxillary arch was done after obtaining informed consent. Rugae pattern was recorded by adding Addition silicone over impression material as it has high tear strength and better accuracy, optimum pressure was applied to make an impression of the upper dental arch for all the subjects and the impressions were then poured with Type 3 dental stone.
The palatal rugae patterns were highlighted by black lead pencil on the cast(photograph1) and were then analyzed following the classification of Martins dos Santos which presented a practical classification based on rugae location(table 1). The classified types of rugae patterns were recorded and the results were observed and tabulated.
This classification indicates and characterizes the following:
Initial rugae; the most anterior one on the right side is represented by a capital letter; Several complementary rugae; the other right rugae are represented by numbers; One subinitial rugae; the most anterior one on the left side is represented by a capital letter; Several subcomplementary rugae; the other left rugae are represented by numbers.
All the 90 working casts showed different rugae patterns. Therefore uniqueness of palatal rugae pattern makes it a characteristic of an individual and thereby aids in personal identification.
In this study each individual had a different set of rugae pattern. However curve forms of rugae were more commonly seen [Graph-1]
In this study Rugae among family members showed different individual patterns Figure-2
To ascertain the permanence and stability of rugae patterns with time and force, it was observed that rugae pattern were found to be consistently stable even at the end of orthodontic treatment suggesting that the orthodontic force have no significant effect on the position and shape of palatal rugae pattern (Fig 3 Table2).
Palatoscopy or palatal rugoscopy, is the name given to the study of palatal rugae in order to establish a person's identity. (10)
In the hard palate, anteroposteriorly a thin central groove is bordered on each side by a crest, the palatal raphae. From this crest, laterally three to seven smaller crests emerge. These crests are called palatal rugae. (10) Rugae develop as localized regions of epithelial proliferation and thickening. (20)
The anatomical position of the rugae in the mouth remains unchanged in its position throughout life, withstands disease, chemical aggression and trauma. It is stable and resists decomposition for up to seven days after death. (10)
The use of palatal rugae in forensic identification is preferred because of their low utilization cost, simplicity and reliability, the study of maxillary dental cast is the most used technique. Thus, it is sufficiently characteristic to discriminate between individuals because no two palates are alike in their configuration. This finding is in congruity with results obtained in the similar studies conducted earlier. (10)
In our study we found that rugae pattern did not simply comprise of one form alone, but appeared as a mixture of varying forms. Curve forms were most commonly seen followed by line and sinuous forms.
"The fibers running anteroposteriorly within the core and in concentric curves across the base of each ruga" determine their orientation and forms.
The varying shapes of palatal rugae can be attributed to the fact that rugae develop as localized regions of epithelial proliferation and thickening. 20 Fibroblasts and collagen fibers then accumulate in the connective tissue beneath the thickened epithelium and assume distinct orientation.
In this study the palatal rugae pattern of all 90 subjects were distinct and unique. None of the patterns were identical and in each individual also no bilateral symmetry was observed. This finding is in congruity with results obtained in the similar studies conducted by English WR. (12,17,19,20,23) This proves that palatal rugae pattern is unique to each individual.
We observed that curve form was most common which is in consistent with, findings of previous study conducted by Nayak et al on Indian population. It can therefore be concluded that certain rugae shapes are specific to particular population and might have better utility in population differentiation. (20)
In comparison of palatal rugae pattern among family members (Father, Mother, Child A and Child B) showed different individual patterns. Although in one of the family few forms were similar but the rugae pattern was not identical which suggests that the role of heredity is uncertain in determining the orientation of rugae pattern
To ascertain if palatal rugae can remain stable due to act of force with time, we recorded and analyzed the pre and post orthodontic casts of 10 males and 10 females, treatment duration ranging from eighteen to twenty four months. Pre orthodontic cast was used as an antemortem record and for superimposition. Post-orthodontic cast represented postmortem record.
On analyzing the post orthodontic casts, rugae patterns remained consistently stable and unaltered at the end of treatment which suggests that rugae pattern remain unchanged during an individual's lifetime and also following action of force.
This is in consistent with the study conducted by Sabet and Abdel. (5,10) The core within the palatal rugae of humans contains elements that are believed to contribute to the maintenance of its shape. The main structural element contains glycosaminoglycans which by its hydrophilic nature causes the tissues to swell and contributes to the maintenance of the shape of rugae through out life. Fibroblasts and collagen fibers beneath the thickened epithelium contribute to the stability of palatal rugae.
In light of these results, we strongly suggest that palatal rugae pattern can be used in forensic science and also for antemortem and postmortem identification.
However, we suggest that further studies should be conducted on a large number of individuals of different races, family members. Also a standard and uniform procedure needs to be put forth for the collection, recording and computerized analysis of the palatal rugae
Human identification of unknown individual has always been of paramount importance to society. It is well established fact that the rugae pattern is as unique to a human as or her fingerprints. It is stable and resist decomposition for up to seven days after death.
The use of palatal rugae in forensic identification is preferred because of their low utilization cost, simplicity and reliability. Thus, it is sufficiently characteristic to discriminate between individuals because no two palates are alike in their configuration. Based on this premise, palatal rugae can emerge as one of the tools for personal identification in forensic science. In view of these significant findings that palatal rugae possess unique characteristics as they are absolutely individual, stable, permanent and unique. Therefore could be used as a personal print for identification and deserves further investigation with larger samples.
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(1) Richard. H. F, O'Shangnessy. P. E. "Introduction to forensic science" Forensic odontology, Dental clinics of North America. 2001;45(2): 217.
(2) Paul Smith. Text book of Forensic Dentistry. 9-10
(3) Acharya. A. B. "Teaching forensic odontology: an opinion on its content and format". European Journal of Dental Education, 10: 137-141.
(4) Nayak P, Acharya A. B., Padmini A. T., Kaveri H. "Differences in the palatal rugae shape in two populations of India". Archives of Oral Biology. 2007;52: 977-982.
(5) English. W. R, Summitt. J. B, Oesterle. L. J, Brannon. R. B, Morlang. W. M. "Individuality of Human Palatal Rugae" Journal of Forensic Sciences. 1988;33: 718-26.
(6) Patil M. S., Patil S. B., Acharya A. B. "Palatine Rugae and Their Significance in Clinical Dentistry: A Review of the Literature". J Am Dent Assoc. 2008;139: 1471-1478.
(7) Caldas. I. M, Magalhaes. T, Afonso. A. "Establishing identity using cheiloscopy and palatoscopy" Forensic Science International. 2007; 165:1-9.
(8) Dayal. P. K, Srinivasan. S. V, Paravatty. R. P. Textbook of Forensic Odontology. Page 1.
(9) Karmakar. R. N Forensic medicine and Toxicology. Page 202.
(10) Abou El-Fotouh M. M. A and El-Sharkawy G. Z. H. "A study of palatal rugae pattern (rugoscopy) in an Egyptian population". Official Journal of the Egyptian Dental Association. 1998; 44(3): 3177.
(11) Fahmi. F. M, Al-Shamrani. S. M, Talic. Y. F. "Rugae pattern in a Saudi population sample of males and females". Saudi Dental Journal. 2001; 13: 92-5.
(12) Ohtani M, Nishida N, Chiba T, Fukuda M, Miyamoto Y, Yoshioka N. "Indication and limitations of using palatal rugae for personal identification in edentulous cases". Forensic Science International, 2008 ;176: 178-182.
Indira AP , Manish Gupta , Maria Priscilla David 
Professor  Professor and Head  Department of Oral Medicine and Radiology M R Ambedkar Dental college and Hospital Bangalore
Senior Lecturer  Department of Oral Medicine and Radiology santosh Dental college and Hospital Ghaziabad, NCR New Delhi
Received: October 14, 2010
Review Completed: November 20, 2010
Accepted: December 19, 2010
Available Online: April, 2011
Email for correspondence: firstname.lastname@example.org
MARTINS DOS SANTOS CLASSIFICATION OF PALATAL RUGAE (Table 1) Anterior Other Rugae Type Position Positions Point P 0 Line L 1 Curve C 2 Angle A 3 Circle C 4 Sinuous S 5 Bifurcated B 6 Trifurcated T 7 Interrupt I 8 Anomoly An 9 TABLE 2: PALATAL RUGAE PATTERNS AMONG 10 MALES & FEMALES WHO HAD UNDERGONE ORTHODONTIC TREATMENT Male Female SL. Ortho NO. Model RIGHT SIDE LEFT SIDE RIGHT SIDE LEFT SIDE 1 PRE C62 C155 C2251 B1531 POST C62 C155 C531 C55 2 PRE L8853 C158 C621 L2155 POST L8853 C158 C621 L2155 3 PRE B552 A151 C135 C222 POST B552 A151 C135 C222 4 PRE B5215 C525 C1555 B2511 POST B5215 C525 C1555 B2511 5 PRE B653 C655 C588 L555 POST B653 C655 C588 L555 6 PRE C655 C256 C535 C515 POST C655 C256 C535 C515 7 PRE C51 C565 L255 B1523 POST C51 C565 L255 B1523 8 PRE L159 B219 C25 B15 POST L159 B219 C25 B15 9 PRE B12 A655 L215 C112 POST B12 A655 L215 C112 10 PRE C253 B51 C1558 C152 POST C253 B51 C1558 C152
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|Author:||Indira, A.P.; Gupta, Manish; David, Maria Priscilla|
|Publication:||Indian Journal of Dental Advancements|
|Date:||Jan 1, 2011|
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