Introduction
Dermatoglyphics/dactylography/dactyloscopy is the scientific study of epidermal ridge pattern on fingers, palm, and soles. The word Dactylography is taken from two Greek words, daktylos meaning finger and graphein meaning to write.1 These epidermal ridge develops due to friction.2 The fingerprint is an impression of these friction skin ridges which is taken upon unglazed paper with the help of printer‘s ink.3 Identification means determination of individuality of a person. It may be complete (absolute) or incomplete (partial). It is used for personal identification, diseases condition, intelligence of individual and in solving disputed paternity.4 Harold Cummins first coined the term Dermatoglyphics in 1926.5 As far back as seventieth century AD, the finger print impressions in ink were used in Assyria and Far East as an evidence of good faith in the sealing of bonds or the issue of documents.6 Sir Edward Richard Henry, Inspector General of Police, Lower Bengal classified the prints for practical application in the field of identification in the 1890‘s.7 So, this fingerprinting system is known as Henry-Galton system or simply, Galton‘s system of identification.8 They are present at birth, both on epidermis and dermis.9 They appear as early as 10wk of intrauterine life and fully developed by 24th week. They appear first on fingers then on palm or sole.10 Once formed, it remains unchanged. So, this is used for identification of individual11 They are unique to individual. Even two hands are entirely different for identical twins also. Herschel first demonstrated this, and his own impressions taken when aged 28 and again at 82 were unchanged except for the addition of coarse lines due to old age.12 Any kind of injuries, old age, diseases etc. will not change the formation of patterns and ridge characteristics, unless the skin is damaged to a depth of about 1 mm. 5
Materials and Methods
A cross-sectional study was done among 200 students.100 were males and 100 were females. The subjects were first year MBBS students of 2018 batch of our Institute. All the subjects were healthy and their age ranged from 17 to 22 years. The written informed consent was taken from the subjects for the study. Ethical approval was obtained from the Institutional Ethical Committee. The objectives of the study were explained to all the participants. They were asked to relax and co-operate to achieve the required movement of the fingers. Finger prints were taken by using Ink Method by “Cummins and Midlo". The materials used were printers, duplicating ink from Kores, ink slab, roller, gauze pads and sheets of paper. The ink was placed on the ink slab and the pad was soaked in it. The ink was evenly spread on the ink slab by roller. The subjects were asked to wash and dry their hands. The printed sheets coded with name, age, sex, address were distributed. The fingers were rolled laterally on the ink slab and then placed on a white paper. The thumb was placed with the ulnar edge downward and rolled toward the body, and other digits were placed with the radial edge downward and rolled away from the body. The fingertip patterns of all the digits were recorded. The fingers were cleaned after taking the prints. The prints were analyzed with the help of the magnifying glass. The following parameters were studied and analyzed: Loops, Whorls, Composite, Arches and their subtypes. These parameters were compared with the previous study values to confirm if there is any correlation between present and previous study. The data was also analyzed for any abnormal new pattern particular to the study group. The frequency of each fingerprint pattern was tabulated and the percentage of each pattern was calculated.
Results
The rolled fingerprints of all ten fingers of 200 subjects were collected. Hence a total of 2000 fingerprints were obtained, which were analysed and their patterns and subtypes were determined. Distribution of different patterns of finger prints are shown in Table 1. Distribution of different fingerprint patterns was analysed separately for both males and females as shown in Table 2. Types of loop pattern with predominance in males and females are shown in Table 3. Types of whorl pattern with predominance in males and females are shown in Table 4. Types of composite pattern with predominance in males and females are shown in Table 5. Types of arch pattern with predominance in males and females are shown in Table 6. Frequency pattern of fingerprints are shown in Table 7.
Table 1
Distribution of different patterns of finger prints
| Pattern | Cases | Percentage |
| Loop | 1140 | 57% |
| Whorl | 605 | 30.2% |
| Composite | 139 | 6.9% |
| Arch | 116 | 5.8% |
| Total | 2000 | 100% |
Table 2
Fingerprint patterns and gender distribution
| Pattern | Male | Female | ||
| No. | % | No. | % | |
| Loop | 555 | 55.5% | 585 | 58.5% |
| Whorl | 330 | 33.% | 275 | 27.5% |
| Composite | 81 | 8% | 58 | 5.8% |
| Arch | 34 | 3.4% | 82 | 8.2% |
| Total | 1000 | 100% | 1000 | 100% |
Table 3
Types of loop pattern
| Types of loop | Male | Female | Total |
| Ulnar | 530- 96.36% | 554 – 94.7% | 1084 -95% |
| Radial | 25-4.5% | 31 – 5.2% | 56 – 4.9% |
| Total | 555- 100% | 585 | 1140 |
Table 4
Types of whorl pattern
| Types | Male | % | Female | % | Total |
| Spiral | 179 | 54.4% | 184 | 66.6% | 363 |
| Circular | 98 | 29.69% | 71 | 25.8% | 169 |
| Double core | 35 | 10% | 10 | 3.7% | 45 |
| Elliptical | 18 | 5.4% | 10 | 3.7% | 28 |
| Total | 330 | 100% | 275 | 100% | 605 |
Table 5
Types of composite pattern
Table 6
Types of arch pattern
| Type | Male | % | Female | % | Total |
| Plain | 28 | 82.35% | 80 | 97.56% | 108 |
| Tented | 06 | 17.64% | 02 | 2.43% | 08 |
| Total | 34 | 100% | 82 | 100% | 116 |
Table 7
Frequency pattern of finger prints
Discussion
This study was conducted to study various patterns of fingerprints and their distribution among medical students. Most common pattern was loop and the least common was arch. In gender distribution, loops were common among females than males. The whorls were more common in male than female. The distribution of loops, whorls, arches and composite is approximately 65%, 25%, 7%, and 2-3% worldwide respectively.13 In our study, slightly different pattern was obtained. The loops were most common, arches were least common. But in a study done by British individuals, the frequency of whorls were higher than loops.14 The frequency of arches were similar to British study but was lower than that of worldwide. The preponderance of loops among medical students in our study is in accordance with the other studies which involved medical students.10, 11 In a study done in Ajmer population, the frequency of loops and whorls were lower than that of arches.10 In Nellimarla, no arches were reported in medical students.11 Loops were the predominant pattern in both genders, followed by whorls. Among Zimbabweans, the frequency of loops was significantly higher when compared to other studies. Igbigbi P.S., Msamati BC reported that Ulnar loops were the most predominant digital pattern type in both the sexes, followed by whorls in males and arches in females.15 The findings were similar to our study. Gangadhar M.R, Rajashekara Reddy. K reported in a study that the basic pattern type loops (57.11%) were common followed by whorls (27.89%) and arches (15.00%) in the general population with significant sex difference.16 Similar findings were noticed in the present study except arches were lower in number. In contrast to this it was found that the frequency of whorls were more in males. Nithin V reported in his study that the most frequent fingerprint pattern was ulnar loop in the total population as well as in the sex wise distribution.17 These findings are in agreement with the present study. Arabind Basu observed high frequency of loops, moderate whorls and low arches.18 Our study revealed same findings. On gender-wise analysis of all types of fingerprints ulnar loop is the commonest.
Conclusion
In this study, distribution of types of fingerprints as well as their subtypes were made out. We found that the distribution of fingerprint patterns in male subjects is similar to that observed in the general sample population, whereas the distribution in female subjects is similar to the general distribution pattern quoted by the previous authors. Little data is available in the literature regarding frequency distribution of subtypes of various fingerprint patterns. Further studies are needed to evaluate the same.
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