A Cheiloscopy Study among Students of Different Regional States in Eastern India: An Institutional Study.

Introduction: India is one of the largest countries which is inhabited by diverse populations of different tribes, castes, religious, and migrant groups. In forensic investigation, personal identification plays the greatest importance. Lip prints are considered as one such tool for personal identification. Study of lip prints is referred to as cheiloscopy and they are considered as unique in every individual just like fingerprints. Materials and
Methods: Three hundred randomly selected specimens were taken in our study comprising of both the genders and of various regions from Odisha, West Bengal (WB) and Bihar was considered in the study. The age selected in our study ranged from 18 to 25 years comprising of 151 males and 149 females. Lip impression was made and viewed for different lip prints pattern under a magnifying glass of 10X.
Results: There was a total of six lip print type identified in the present study. The type of lip print pattern found more in males was Type 2 and in females was Type 1. The type of lip print pattern found more in Bihar and WB was Type 2 and Odisha was Type 1.
Conclusion: As the lip print is unique for every individual, Cheiloscopy is considered as a useful method of identification in forensic odontology. The study showed statistically significant difference in gender with a variation in geographical location. Copyright:

INTRODUCTION

India is one of the largest countries which is inhabited by diverse populations of different tribes, castes, religious and migrant groups. The people of India share few similar physical features but they also show differences in their cultural, anthropologic, and genetic triats.[1]

In forensic investigation, personal identification plays the greatest importance. It is usually based on the theory which says that all the individuals are unique and they are only identified on individual characteristics features. The biologic phenomenon of characteristic patterns seen on the vermilion border of lips was first described by Fischer in the year 1902. However, Snyder in 1950 was the one who gave the idea of using lip prints as an identification tool.[2]

A normal wrinkle and groove present in between the inner labial mucosa and outer skin is defined as lip prints and the examination of it is known as cheiloscopy.[3] In the year 1970, Suzuki and Tsuchihashi coined the term “Sulci labiorum” and the lip prints consisting of these grooves as “Figuralinearum labiorumrubrorum.” The studies of these lip prints are referred to as cheiloscopy and they are considered as unique in every individual just like fingerprints.[4] The techniques used in cheiloscopy are valued the same way like other types of forensic evidence which are generally used for personal identification as well as sex determination.[5] A classification method of lip prints was devised by Suzuki and Tsuchihashi in 1970 which is the most widely used classification in literature[6] [Figure 1].

Figure 1

Type I – A clear-cut groove running vertically across the lip. Type I' – Partial length groove of Type I. Type II – A branched groove. Type III – An intersected groove. Type IV –A reticular pattern. Type V – Morphologically not differentiated (undetermined)

In the following study, we aim to analyze the different lip print patterns in human subjects based on their gender and geographical background. We also tried to see if there are any similarities of any particular pattern among the subjects. To the best of our knowledge, this is the first lip print study in literature where both the genders and population of 3 different states have been compared.

MATERIALS AND METHODS

Subjects

Three hundred randomly selected specimens are taken in our study comprising of both the genders and of various regions from Odisha, West Bengal (WB), and Bihar. The age selected in our study ranged from 18 to 25 years comprising of 151 males and 149 females.

Exclusion criteria

Participant suffering from any lip deformity, allergy to agents utilized during the sample collection and any lip inflammation was not considered in our study.

Ethical considerations

Informed valid consent was taken from each participant before the sample collection and ethics committee approval (Ethical approval no. KIIT/KIMS/IEC/308/2020) was also obtained for the same. The specimens were coded and documented accordingly.

Recording and examination of lip prints

Dark Red or pink nonglossy, nonmetallic lipstick was applied with a single stroke evenly upto vermillion border. The lipstick was applied onto cleaned and dry lips and left for 2 min. The lip impression was made on the strip of cellophane tape and sticked to white thin bond paper (A4 70 GSM). The impression for different lip prints pattern was viewed under a magnifying glass of 10X. The same method was followed for taking the impressions from all subjects. The lip print was divided into four quadrants from the center of lip, labeled as 1st Quadrant, 2nd Quadrant, 3rd Quadrant, and 4th Quadrant for its examination which was then classified into 6 patterns based on the classification given by K. Suzuki and Y. Tsuchihashi's classification.

RESULTS

A total of 300 participants were included for the present study. The mean age of the study population was 21.76 ± 1.894. The distribution of the population included 50.3% males and 49.7% females. The geographic distribution included 33% of the population from Bihar and WB and 34% of the population from Odisha [Figure 2].

Figure 2

Graphical representation of the demographic characters of the sample population

There was a total of six lip print type identified in the present study. The lip prints were recorded based on four quadrants. The distribution of these types according to the geographic location has been mentioned in Table 1.

Table 1

Distribution of the type of lip print based on the location*

Location	Classification of lip print	1st quadrant, n (%)	2nd quadrant, n (%)	3rd quadrant, n (%)	4th quadrant, n (%)
Bihar (n=99)	Type 1	28 (28.3)	24 (24.2)	34 (34.3)	40 (40.4)
	Type 1’	1 (1.0)	2 (2.0)	0	0
	Type 2	39 (39.4)	41 (41.4)	43 (43.4)	38 (38.4)
	Type 3	7 (7.1)	7 (7.1)	13 (13.1)	10 (10.1)
	Type 4	24 (24.2)	25 (25.3)	9 (9.1)	11 (11.1)
Odisha (n=102)	Type 1	30 (29.4)	30 (29.4)	44 (43.1)	41 (40.2)
	Type 1	8 (7.8)	7 (6.9)	3 (2.9)	3 (2.9)
	Type 2	32 (31.4)	33 (32.4)	36 (35.3)	38 (37.3)
	Type 3	5 (4.9)	5 (4.9)	3 (2.9)	5 (4.9)
	Type 4	25 (24.5)	26 (25.5)	15 (14.7)	14 (13.7)
	Type 5	2 (2.0)	1 (1.0)	1 (1.0)	1 (1.0)
WB (n=99)	Type 1	25 (25.3)	23 (23.2)	33 (33.3)	31 (31.3)
	Type 1’	10 (10.1)	10 (10.1)	1 (1.0)	1 (1.0)
	Type 2	39 (39.4)	41 (41.4)	45 (45.5)	43 (43.4)
	Type 3	4 (4.0)	2 (2.0)	9 (9.1)	11 (11.1)
	Type 4	21 (21.2)	23 (23.2)	11 (11.1)	13 (13.1)
F score		0.165	0.325	0.515	0.814
P		0.85	0.723	0.598	0.44

*Type 1=Type I, Type 1’=Type I’, Type 2=Type II, Type 3=Type III, Type 4=Type IV, Type=Type V. WB: West Bengal

For the population residing in Bihar, Type 1 was the most common for 4th quadrant (40%), Type 1' was the most common for 2nd quadrant (2%), Type 2 and Type 3 for the 3rd quadrant (43.4%, 13.1%, respectively), Type 4 was most common in 2nd quadrant (25.3%). The least common was Type 1 for 2nd quadrant (24.2%), Type 1' for the 3rd and 4th quadrant (0%), Type 2 for the 4th quadrant (38.4%), Type 4 for the 3rd quadrant (9.1%). Type 3 had an equal distribution for the 1st and the 2nd quadrant (7.1%).

For the population in Odisha, Type 1 was commonly found for the 3rd quadrant (43.1%), Type 1' for the first quadrant (7.8%), Type 2 for the 4th quadrant (37.3%). Type 3 was almost equivalently distributed among the 1st, 2nd, and 4th quadrant (4.9%). Type 4 was commonly present in the 2nd quadrant (25.5%) and Type 5 in the 1st quadrant (2.0%). The least common type was Type 2 for the 1st quadrant (31.4%), Type 3 for the 3rd quadrant (2.9%), and Type 4 for the 4th quadrant. Almost an equal distribution was seen for Type 1 in the 1st and 2nd quadrant (29.4%), Type 1' for the 3rd and 4th quadrant (2.9%), and Type 5 for the 3rd and 4th quadrant (1.0%).

For the population of WB, Type 1 was most common for the 3rd quadrant (33.3%), Type 2 for the 3rd quadrant (45.5%), Type 3 for the 4th quadrant (11.1%), and Type 4 for the 2nd quadrant (23.2%). Type 1' had almost equal presentation, with 10.1% for the 1st and 2nd quadrant. It was seen that the 3rd and 4th quadrant also had an equal presentation of 1% each. The least common was Type 1 for 2nd quadrant (23.2%), Type 2 for the 1st quadrant (39.4%), Type 3 for the 2nd quadrant (2.0%), and Type 4 for the 3rd quadrant (11.1%). Type 1' had an equal distribution for the 3rd and the 4th quadrant (1.0%).

There was no statistically significant difference noted when comparisons were made between the different locations. For the 1st quadrant, interstate comparison showed a P = 0.85, for the 2nd quadrant, it was 0.723, 3rd quadrant, it was 0.598, and 4th quadrant, it was 0.44.

The gender-wise distribution of the lip print type as recorded quadrant wise has been mentioned in Table 2. For the male population, Type 1 was most common for the 4th quadrant (29.8%), Type 1' and Type 5 for the 1st quadrant (4.6%, 1.3%, respectively), Type 2 and Type 3 for the 3rd quadrant (47.7%, 13.2%, respectively), and Type 4 for the 2nd quadrant (20.5%). The least common type of lip print was Type 1 and Type 3 for the 2nd quadrant (27.2%, 8.6%), Type 2 for the 1st quadrant (36.4%), Type 4 for the 3rd quadrant (10.6%). Equal distribution was seen for the Type 1' for 3rd and 4th quadrant (0%) and Type 5 for the 2nd, 3rd, and 4th quadrant (0.7%).

Table 2

Distribution of the type of lip print based on gender

Gender	Classification of lip print	1st quadrant, n (%)	2nd quadrant, n (%)	3rd quadrant, n (%)	4th quadrant, n (%)
Male (n=151)	Type 1	44 (29.1)	41 (27.2)	42 (27.8)	45 (29.8)
	Type 1’	7 (4.6)	6 (4.0)	0	0
	Type 2	55 (36.4)	59 (39.1)	72 (47.7)	68 (45.0)
	Type 3	14 (9.3)	13 (8.6)	20 (13.2)	19 (12.6)
	Type 4	29 (19.2)	31 (20.5)	16 (10.6)	18 (11.9)
	Type 5	2 (1.3)	1 (0.7)	1 (0.7)	1 (0.7)
Female (n=149)	Type 1	39 (26.2)	36 (24.2)	69 (46.3)	67 (45.0)
	Type 1’	12 (8.1)	13 (8.7)	4 (2.7)	4 (2.7)
	Type 2	55 (36.9)	56 (37.6)	52 (34.9)	51 (34.2)
	Type 3	2 (1.3)	1 (0.7)	5 (3.4)	7 (4.7)
	Type 4	41 (27.5)	43 (28.9)	19 (12.8)	20 (13.4)
	Type 5	0	0	0	0
Z score		0.176	0.220	9.06	6.165
P		0.675	0.640	0.003*	0.014*

*Statistically significant

For the female population, the most common type was Type 1 for the 3rd quadrant (46.3%), Type 1', Type 2, and Type 4 for the 2nd quadrant (8.7%, 37.6%, 28.9%, respectively), and Type 3 for the 4th quadrant (4.7%). The least common type was Type 1 and Type 3 for the 2nd quadrant (24.2%, 0.7%), Type 2 for the 4th quadrant (34.2%), Type 4 for the 3rd quadrant (12.8%). Equal distributions were seen for the Type 1' pattern for the 3rd and the 4th quadrant (2.7%). Type 5 was absent for the female population.

A statistically significant difference was noted between the males and females for the 3rd quadrant (P = 0.003) and the 4th quadrant (P = 0.014). There was no statistically significant difference noted for the 1st (P = 0.675) and the 2nd quadrant (P = 0.640).

DISCUSSION

There are various methods of human identification, out of which fingerprint and DNA analysis are common techniques. The pattern of lip prints is permanent and remains unchanged even after death except in monozygotic twins. The lip print patterns are unique; hence, they are useful in personnel identification and forensic investigations. Different methods are used for recording lip prints; in the present study, conventional lipstick method is used.

The present study is the first to compare the pattern of lip prints in Eastern Indian population. No statistically significant difference was noted when comparisons were made between the different states. Statistically significant difference was noted between the male and female for 3rd and 4th quadrant. No statistically significant difference was noted for 1st and 2nd quadrants.

The most common lip print pattern observed in our study from the states (region) was Type 2 [Table 1], which was similar with the study conducted by Makesh Raj et al.[4] where they found Type 2 pattern to be common in upper lip of males. Dwivedi et al.[7] also found that Type 2 is the most common pattern. Another study conducted by Bharathi and Thenmozhi[5] found Type 2 to be the most predominant lip print pattern in the upper lip of males and in females, lower left lip showed Type 2 pattern to be most predominant.

In Odisha's population, the most predominant pattern was Type 1 which was in coincidence with Kapoor and Badiye in Indian sample population of 200 persons.[3] Our results were also in coincidence with the study conducted by Ghimire et al.[6] in Nepalese students in which Type 1 pattern was the most common pattern found in all the four quadrants of both males and females. Another study conducted by Ranjan et al.[8] showed that Type 1 pattern was the most common pattern found in the population of students from Divya Jyoti College of Dental Sciences and Research, Modinagar (Uttar Pradesh).

Alzapur et al.[9] also found Type 1 pattern to be the most common lip print pattern in 100 medical students of Telangana. Similarly, Vahanwalla and Parekh[10] also showed similar results in Mumbai population. A similar study was conducted by Kaul et al.[1] in various Ethno–racial Groups in India and found Type 1 lip print pattern was the most prevalent pattern in both males and females. Sivapathasundharam et al., Sharma et al., Verghese and Mestri confirmed that the most prominent pattern was Type 4,[39111213] similarly Gondivkar et al. and Saraswathi et al.[1415] showed Type 3 to be the most predominant type which was contrasting with the present study.

Tsuchihashi studied the lip prints of 1364 Japanese men and women and found that in both genders, Type 3 was most common. Loganadan et al.[16] conducted a study of lip print patterns in children and their parents among Deutero-Malay population in Indonesia, they found that Type 1' is the most dominant lip print type in the population. Similarly, Bindal et al.[17] used 60 samples from three races of Malaysia and observed Type 1' pattern as the most common pattern.

CONCLUSION

As the lip print is unique for every individual, Cheiloscopy is considered as a useful method of identification in forensic odontology. The present study found Type 2 pattern to be the most prevalent pattern in the states of Bihar and WB and Type 1 in Odisha population. We concluded that the study showed statistically significant difference in gender with a variation in geographical location. Hence, lip prints study or known as cheiloscopy is considered as a useful adjunct of identification in the field of forensic odontology.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.