Correlation Between Tongue Prints and Lip Prints in ABO Blood Groups

Introduction

Each individual has unique characteristics that set them apart from others.¹ Any form of physical trait can be used to identify a suspect of an offence because of the rising demands placed on law enforcement to produce adequate physical evidence connecting a perpetrator to a crime.² A person's ‘‘IDENTITY’’ is made up of a variety of functional, pathological, and psychically normal bodily traits. Individual identification is a crucial and demanding process in Forensic science and investigation.³ 

The oral opening is surrounded by two fleshy folds called the lips. Internal mucosa and external skin lines them. At the vermilion boundary, a reddish area covered by thin keratinized epithelium, the skin and mucosa form one continuous layer. The oral fissure, which forms the angle of the mouth is located immediately above the cutting edges of the upper incisor teeth, and a labial commissure on either side is often located close to the first premolar tooth. In comparison to the skin, the vermilion area's epithelium displays a less developed stratum corneum.

A distinctive pattern known as a lip print is made up of several elevations and depressions on the lip. Cheiloscopy is the term for the study of lip impressions.⁴ Since each person's lip print is distinctive and does not alter over the course of a lifetime, it is utilized for personal identification. If the lines are not visible, only the contour of the lips is printed. Otherwise, a lip print is disclosed as a stratified surface trace with visible portions of lines, particularly the furrows.⁵ It has been demonstrated that they recover after going through changes like trauma, inflammation, and infections like herpes, and that the form and disposition of the furrows are not affected by environmental factors. Lip prints have also been acknowledged and approved as a global standard for personal identification.^6,7 Yasuo Tsuchichashi divided lip prints into six categories based on the shape and direction of the grooves.^8,9 Lip prints are a permanent record of identification, just like finger prints. The blood group is yet another element of a person's biology that does not alter over the course of their lifetime. Finding a person's blood type using samples taken at the scene of the crime aids in identification. Under the ABO blood group classification, Landsteiner categorized blood types.³ Physical traits need to be persistent and distinct in order to be employed as identifying markers. From birth till death, an individual's blood group, tongue print, and lip print will all remain unaltered.³

To begin with, the tongue's form and surface textures are specific to each individual. Second, the only internal organ that can be exposed for inspection in a completely normal and painless manner is the tongue. This is beneficial because the exposed part of the tongue contains majority of the shape and textural data that may be seen in photos, referred to as ‘‘tongue-prints.’’ The ‘‘lingual impression’’ is the imprint of the dorsal surface and lateral borders.

The physiological texture is constant and the individual lingual form is constant. Thirdly, despite its natural wiggle, physiological textures remain consistent and despite variations in the tongue's coating, the form of each individual tongue remains constant over time. Fourthly, unlike the fingers, for instance, the tongue of a person is isolated and shielded from the outside world because it is housed within the mouth. The practice of looking at the tongue is also a trustworthy indicator of life.¹⁰ The most accurate method for replicating even the tiniest details, alginate moulding represents a criterion with force of evidence up on uniqueness for each and every individual. With the aid of this criterion, Forensic dentistry identification provides information with predictive values as far as a person's identity is concerned.¹¹ In Traditional Chinese Medicine (TCM), the tongue is referred to as the “Tongue of Life’’ since it is a vital organ and has a vibrant colour. On the other hand, the “Tongue of Death’’ is known for its gloomy and withered appearance.

Since it is an internal organ and a sign of life, whether the individual is alive or dead, its uniqueness is further highlighted by this fact. A tongue can only be thrust out for examination when a person is still alive. When the tongue retracts to block the airway, it frequently results in mortality, especially in sleep apnea sufferers.¹² According to TCM, the general texture of the tongue differs from person to person and is influenced by diseases, making it a good tool for diagnosing health issues. Clear changes can be noticed with a simple visual comparison.¹³ Even though the tongue is one of the primary components for diagnosis in TCM, its usage in natural and man-made disasters is still undocumented.

Objectives of the Study

Individuals selected for the study were categorized as:

Group 1: Included 15 boys studying BDS I year (aged 19-23 years)

Group 2: Included 15 girls studying BDS I year (aged 19-23 years)

1. To record and analyze lip and tongue prints and blood group typing (ABO).

2. To correlate amongst them, which could finally help in personal identification.

Materials and Methods

Source of data

The study population was drawn from the first year BDS students attending the Department of Oral Pathology, Narayana Dental College and Hospital, Nellore, Andhra Pradesh. 

Method of collection of data

The students were selected based on the following criteria.

Inclusion criteria

1. Age group between 19-23 years.

2. Subjects with lips free from any active or passive lesions, those who provided consent and reported no hypersensitivity to lipsticks.

3. Only healthy subjects free from any oral pathologies, inflammation, and reported no hypersensitivity to alginate.

4. Blood group typing (ABO).

Exclusion criteria

1. Subjects who underwent lip surgery or those with a history of lip trauma or developmental anomalies.

2. Subjects with abnormalities or deformities of tongue, cut marks and surgical scars.

Screening examination included

1. Medical and dental histories of the subjects were determined.

Materials used

1. Magnifying glass, ear bud, mouthwash, cellophane tape, bond paper, lipstick, alginate, dental stone type IV, curved spatula, rubber bowl, kidney tray, cotton rolls, gloves, mouth mask, diagnostic instruments.

Method of data collection

First, the labial mucosa was cleansed. Lipstick was applied to the subjects using an ear bud. The subject's lip print was captured on bond paper and labelled using a cellophane tape. Students' ABO blood groups were noted after appropriate questioning, and blood tests were administered to those who were unsure of their blood type. While performing the tongue examination, oral cavity was thoroughly rinsed with mouthwash. The subjects were also instructed to protract their tongues gradually rather than abruptly up to maximum protraction in order to avoid a noticeable contraction of the striated lingual muscles that would alter the tongue's characteristics as well as its shape. To highlight morphological traits such as shape, type, characteristics of the longitudinal medial septum and corresponding grooves, as well as the lingual apex type, direct examination of the tongue was performed. The alginate-moulded impression with the advantage of accurately replicating the smallest features and simply peeling off the model, was considered the most accurate impression suited for study models. With the aid of alginate, which was immediately placed from the level of the oral commissures up to the lingual tip to avoid the regurgitation reflex, the dorsal surface and the lingual lateral margins were captured as an impression. In order to have a suitable positive image for identification, type IV dental stone was used to pour the moulds that were recorded. The lip prints and tongue prints were initially evaluated after recording. If the print was not reasonable, another print from the same subject was recorded.

Statistics

• To study different lip and tongue print patterns and ABO blood group typing, percentages of the individual parameters were used.

• Chi-square test was used to determine the correlation between all the above.

Results

The present study was conducted to determine if there is any correlation between lip print pattern, tongue print pattern and blood group. The samples were collected from 30 subjects, 15 male and 15 female participants. The samples were examined and the results obtained are as follows.

Among thirty individuals, branching lip prints were observed in 40% (12 individuals), vertical in 43% (13 individuals), intersecting in 3% (1 individuals), reticular in 13% (4 individuals). In tongue prints, longitudinal medial septum straight pattern was seen in 33% (10 individuals), followed by zagged in 8 individuals (26.67). Among papillae of tongue, fungiform was noticed in 21 individuals (70%), 12 individuals (40%) showed ovoid pattern. O positive and B positive were same in number i.e., 12 individuals (40%). Chi square values for lingual mucosa (LM), papillae and shape of the tongue were 8.23, 1.04, 0.77, respectively, while the p values were 0.143, 0.59, 0.020, respectively. For blood groups, Chi square value was 6.00 and p value was 0.1991. For lip prints, Chi square value was 1.41 and p value was 0.7031. In our study, vertical lip print pattern showed highest predilection compared to any other types. Therefore, the comparisons were drawn between the vertical lip print pattern and the blood groups and tongue prints. Chi square values for blood groups, Longitudinal medial septum (LMS), papillae, shape of tongue for vertical lip pattern were 6.629, 3.34, 0.93, and 0.77, respectively while the p values were 0.084, 0.502, 0.626, 0.020, respectively.

Discussion

Certain characteristics help to identify a person. These can be as precise as DNA typing at the molecular level or as macroscopic as blood groups, tongue prints, and lip prints. A physical trait must be distinct and unchangeable in order to be utilized as an identity marker. Blood groups, tongue prints, and lip prints are biological traits that remain constant from birth till death in a person. The goal of the current study was to investigate if any relationship exists between blood groups, tongue and lip prints, in the people of Andhra Pradesh. As a layered surface trace with discernible elements of lines, such as the furrows, a lip print may be discovered. Lip prints are distinctive and remain constant during a person's lifetime. The first anthropologist to describe the furrows on the red portion of the human lips was Fischer in 1902. Edmond Locard, one of France's foremost criminologists did not advocate the use of lip prints for criminality or personal identification until 1932.

The qualities of the lips generated by lip grooves are as uniquely different as the ridge characteristics of fingerprints, according to Snyder's description from 1950 in his book on homicide investigation. In order to gather information for practical forensic applications, Suzuki conducted in-depth examinations of measurements of lips, the use and colour of rouge, and the process for its extraction in 1967.5 Later, Suzuki and Tsuchihashi gave the grooves on the labiorum rubrorum the name ‘sulci labiorum’ and the name ‘figura linearum labiorum rubrorum’ for the lip prints made up of these grooves. Cheiloscopy is one of the specialized methods used for personal identification, according to Cottone, who wrote about it in his book ‘Outline of Forensic Dentistry’ in 1982.

Classification of lip prints

In 1967, Santos classified lip grooves into four types.

1. Straight Line

2. Curved Line

3. Angled Line

4. Sine-Shaped Line

Suzuki and Tsuchihashi in 1970, devised a classification where they divided lip grooves into⁵

1. Type I – A clear cut groove running vertically across the lip

2. Type I’ – Partial length groove of Type I

3. Type II – A branched groove 4. Type III – An intersected groove

5. Type IV – A reticular pattern

6. Type V – Other patterns

Man always had a curious attraction to blood. The RBC membrane contains saccharide groups of glycoproteins known as A and B antigens. These antigens are known as ‘‘iso-antigens’’ since they are not shared by all members of the specific species. ‘‘Iso-alleles’’ are the alleles that control whether these antigens are present or absent. Individuals may be classified as belonging to one of the four blood groups, A, B, AB, or O based on the presence of these blood group antigens.¹⁴

In terms of shape analysis, the longitudinal medial septum's morphological characteristics and associated grooves (whose existence was confirmed by each individual's lingual inspection; we used this ‘‘morphological notion’’ in our study to examine the characteristics of these related grooves and quantify the degree to which these contribute to defining a person's individuality. With the exception of the tongue tip, the longitudinal septum occupies more than two thirds of the tongue's dorsal surface and has a twisted, interrupted, narrow, and slightly deep look. On both sides of the central septum, there are numerous, tiny, thin grooves that are connected to it by different shapes, including straight, curved, and jagged lines. They are forked, oblique, random, perpendicular, and bearing in a circle. It has a ‘‘U’’ like form with a slightly rounded off tip. The form of the tongue was another morphological trait that was observed. Based on the examination conducted, we categorized it as ovoid, ellipsoid, rectangular, pentagonal, trapezoidal, or asymmetrical, with the last of these being excluded from any geometric shape. Thus, it was observed that the longitudinal grooves can have varied shapes, a rectilinear or twisted course, and a superficial or deep profile, and that they can run over any part of the dorsal surface or, in some cases, along its whole length.¹¹ A vertical pattern with a high B positive blood group frequency can be seen in lip prints.

Positive blood group O and positive blood group B showed the highest distribution patterns. O positive blood group displayed branching, A positive blood group displayed reticular, while B positive blood group exhibited a more vertical pattern. The ovoid shape of the tongue was more frequently observed, and the straight pattern was more prevalent in tongue prints LMS. Fungiform showed the highest inclination. All these factors are significant in Forensic investigations. The correlation analysis of these indicated no relationship between them. Blood groups, tongue prints, and combinations of these three cannot be utilized for identifying purposes alone. Instead, they can be used to support facts in crimes where there is scant or no available evidence. Similarly, blood group association with lip print pattern was not evident.⁶ Gender, ABO blood types, or intercommissural distance (ICD) did not show correlation with the lip print pattern.¹⁵ There was no connection between blood types and lip prints.¹⁶ There was no statistically significant relationship between blood group, finger print, and lip print.¹³ There was no discernible relationship between blood types and lip prints.¹

Conclusion

Every individual has a different dorsal surface of the tongue in terms of morphology. Along with rugoscopy and cheiloscopy, the lingual impression and its digital image may comprise secure procedures for Forensic dentistry identification. From a morphological and structural perspective, the dorsal surface of the tongue offers important characteristics, particularities that have not yet been researched. When teeth are lost, it may be challenging to compare both antimortem and postmortem records. Soft tissues can therefore be easily recorded and utilized as evidence in the identification of individuals and the management of disasters because they are present consistently throughout life.

Conflict of Interest

Nil