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Medico-Legal Update

Study of Lip-Prints as Aid for sex Determination

Author(s): Vahanwala Sonal, Nayak C.D., Pagare S.S.

Vol. 5, No. 3 (2005-07 - 2005-09)

(1)Vahanwala Sonal, (2)Nayak C.D., (3)Pagare S.S.

(1)Lecturer, (2)Prof. & Head, (3)Professor
Department of Oral Medicine & Radiology
Padmashree Dr.D.Y.Patil Dental College & Hospital, Nerul, Navi Mumbai

Historically, human identification is one of the most challenging subjects that man has confronted. The concept of “identity”, is a set of physical characteristics, functional or psychic, normal or pathological – that define an individual.

Nowadays, human identification is a universal process based on scientific principles, mainly involving fingerprinting, the objective of which is to identify and register individuals for both civil and criminal identification purposes.

Cheiloscopy has been a subject of great interest to most researchers, it being the least invasive and easily available mode for study purpose.

Theory of uniqueness is a strong point used in the analysis of fingerprints and bitemarks, to convince the court of law. Likewise, even the lip-prints or the vermillion border is unique of an individual and hence behold the potential for identification purpose.

Study of lip-prints has been the subject of French doctoral dissertation, according to which the lip-print patterns appear to be genotypically determined and unchanged from birth1

The forensic application of lip prints has been studied mostly by the Japanese(2,3,4). The most characteristic groove patterns of human lips could be recorded in a cross line diagram(similar to traditional dental charting of the quadrants) the lip print diagram.

Right upper lip
I quadrant
Left upper lip
II quadrant
Right lower lip
IV quadrant
Left lower lip
III quadrant

In one forensic case, the colourful lipstick imprints on some female underwear resulted in the elimination of one suspect and the identification of another, who turned out to be a near relative(4)

Suzuki(5), in 1970 tried to present categorically,the lip mark as a tool for identification. He classified the natural lip marks/fissures in four types; refer photograph.

Type I: Vertical, comprising of complete [end to end] longitudinal fissures/patterns
Type I: Incomplete longitudinal fissures
Type II: Branching Y shaped pattern
Type III: Criss-cross pattern
Type IV: Reticular, typical chequered pattern, fence like.

Studies(1,5) done previously showed that patterns remain unchanged over a person’s lifetime. Yet another study revealed that the twins possessed a very similar lip pattern. Also, a 3 year old study was done to confirm that the lip marks do not change. In a study conducted by Vahanwala-Parekh(6), it was suggested that certain pattern trends were prevalent in either sex.

Lip-pattern region of occurrence Predominantly seen in
a. Type I & Type I 1st quadrant[right upper lip] Female
c. Type II 2nd quadrant[left upper lip] Male
d. Type III Never occurs in lower lip. If so then only in male
e. Varied patterns in all quadrants Male
f. Same[alike] patterns in all quadrants Female

The prime objective of the present study was to ascertain whether the lip-prints behold the potential for determination of sex of the individual from the configuration


Materials: A dark coloured frosted lipstick
Thin bond paper
Magnifying lens
Pen/ pencil for labelling the individual details

Method: In present study, 20 subjects were males and 30 were females, in the age group of 19-29 years. Care was taken to select individuals having no lesion, whether active or passive on the lips. Individuals with known hypersensitivity to lipsticks were not included in the study. The lipstick was applied by the research personell with a single stroke, evenly on the vermillion border. The subject was asked to rub both the lips to spread the applied lipstick. Researcher 1 was trained to get lip-prints on paper such that each of them could show the fissures and grooves properly. The set of lipprints were obtained on simple bond paper in the traditional method as suggested in the study(6).And it was coded, keeping in account the name & sex of respective individuals. Thus he presented following type of paper:

Name Lip-print sex code
  Example1 Female 1

[table A]

Following paper deviced by Researcher 1, was then passed on to Researcher 2

Code Lip-print

[Table A2]

Researcher 2 with sound knowledge of Suzuki’s classification(5) was given the above coded paper with lip-prints and systematically each lip-print obtained was designated quadrantwise from the corner of right side to corner of left side both on upper as well as lower lip. He now tabularised the configuration as given below:

Code Lip-print configuration

[table B]

Now Researcher 3 who had knowledge about prevalence of certain trends of Suzuki’s classification in different sex, ascertained the sex of the individual from the configuration laid down by Researcher 2, which appeared as:

Code Configuration Determination of sex

[table C]



Discussion of a lip print examples

Configuration of the lips Estimation & Justification
Configuration of the lips Female
Since the configuration is monotonous,
Type I, I’ is dominant
Configuration of the lips Female
I & II are dominant
Uniform configuration
Configuration of the lips Male
Type III present
Varied patterns

Eventually table A and table C were utilized to coincide the findings.


Actual study sample comprised of 30 females and 20 males.

Researcher no.3, who was given the labelled paper analysed and allotted the configuration of the lip-prints could manage recognizing them.

According to him, all the 30 females were correctly recognized as females on the basis of their lip-prints. Of the actual 20 lip-prints of the males, 16 of them were correctly identified as males, 1 as a female and 3 such lip-prints could not be classified whether male of female!!! Thus the result obtained in this study could be expressed in the following tabular form as:

  Female Male Undecided Total
Actual 30 20 - 50
Researcher 31 16 3 50

Step 3 in the study, i.e. gauging the sex of the individual from the configuration of the lipprints was repeated for six set of observations.


Actual Females = 30

Set no. Diagnosed correct Diagnosed wrong Undecided
1 30 0 0
2 30 0 0
3 30 0 0
4 30 0 0
5 30 0 0
6 30 0 0

Conclusion – 100%

For all six observations, the female subjects were correctly diagnosed!

Actual Males = 20

Set no. Diagnosed correct Diagnosed wrong Undecided
1 16 1 3
2 15 1 4
3 18 - 2
4 16 1 3
5 17 1 2
6 17 2 1

x2 Test was carried out due to discrepancy in the result

Simplified version of this observations could be tabulated as

Sample 1 2 3 4 5 6
Observed value 16 15 18 16 17 17

Applying formula, x2

x2 = ?[observed value- expected value]2

expected value = (42+ 32+ 22+ 42+ 32+ 32) / 20

= 916 + 9 + 4 +16 + 9 + 9) / 20

= 63 / 20

= 3.15

The table value of x2 at 5% level of significance for 5 degree of freedom is 11.07

Calculated value of x2 is less than that of x2 at 5% level of significance.

[3.15 < 11.07]

We accept the hypothesis and the study is reliable.


Determination of the sex of the individual by forensic methodology is warranted in cases of

  1. heirship
  2. marriage
  3. divorce
  4. legitimacy
  5. rape

Some methods of determination include:

  1. Detection of sex-chromatin e.g. Barr bodies seen in females
  2. Various physical(7) sex traits e.g.
    1. Females show a more vertical ilium. The distance between the iliac crests is less, with shallow fossae and more marked curves of crest and rounded margins wall.
    2. The pelvic cavity is conical & funnel shaped in males as contrast to females, which is broad and round
  3. From the standard values of measurement of bones
    1. a]neck makes obtuse angle with the shaft, about 125 degrees in males. Whereas in females it is less obtuse
    2. b]orbits in females are rounded, higher, relatively larger, sharper margins. Whereas in males it is square, set lower on the face, relatively smaller
    3. Mastoid process in males is medium to large, round and blunt Whereas in females it is small to medium, smooth and pointed
  4. Characteristic mandible e.g
    1. In males the body height is greater at symphysis, as compares to females
    2. The angle of the body and ramus is less obtuse[under 125 degrees]; prominent and everted in males as compared to more obtuse, not prominent and inverted in females.
  5. In advanced putrefaction, sex can be determined by identifying uterus or prostate which resist putrefaction for a long time.

Criminals may conceal their sex to avoid detection by changing dress or by other methods. This can be detected by physical examination. Determination of the same can be accomplished with the help of skeleton and the medullary According to Krogman, the degree of the accuracy in sexing adult skeletal remains is as follows;

Entire skeleton=100%, pelvis alone=95%, Skull alone=90%, pelvis plus skull=98%, long bones alone=80%

All the methods of determination of sex of the individual can be predicted only by obtaining their body parts- in short when the culprit and the criminal both are dead!!

With the advent of science and complicated technologies, man is been quite successful in deceiving “The Law”. Mastering the loopholes and masking sheer facts is very easy now. Hence the criminal can be scot-free by deceiving the law and misguiding the police as well as the investigators. But, “Truth should prevail as truth”

The Lip-prints can therefore be used, as they get registered easily even on a steel or glass tumbler. Presence of lip-prints is conclusive of the fact whether the beholder was a visitor or is related to the site of crime or not.

If the sex of the individual is known, it is easy to short-list the array of suspects with motive of the crime.

The present study is able to convey that lipprints behold the potential of determination of the sex. As the table of accuracy reveals…the female subjects were identified without any mistakes or doubts i.e. 100% results were obtained.

The accuracy percentage fell in identification of the males. An error was encountered & quite a bit was of questionable status i.e. the lip-print configurations were correctly noted but the researcher was unable to decide whether it was a male or a female print. This we reasoned out as

1] Trends of both the sexes were prevalent at the same time

2] Variant Types in all quadrants made decision making for the researcher little difficult.

Statistical values obtained conclude that since calculated value of x2 is less than that of x2 at 5% level of significance, we can accept the said study/hypothesis to recognize the sex of an individual.

Still some more studies need to be carried out and various trials to be studied so that one fine day we can lend our lip for the purpose of personal identification.

Lip-prints just like the fingerprints if get registered at the vicinity of crime, can often be retained on the object. Then can be exposed with the help of zinc oxide powder which further can aid to recognition of the sex of the individual and later in turn matched with the prints of prime suspects. Though the results obtained by our study, does not prove to be a full-proof one nevertheless it does seem to promise to go one step closer to the “Truth”…..locating justice.Lipprints thus hold potential promise as a supplementary tool alongwith other modes to recognize the sex of an individual


  1. Renaud M.: Lip print identification in legal medicine, review of French doctoral dissertation, NOUV presse Med 2: 2617- 2620,1973.{cited from Textbook on oral Biology by Shaw, chapter 34}
  2. Suzuki K., Tsuchihashi Y.: personal identification by means of lip prints. J.Forensic Med. 17:52-57, 1970
  3. Tsuchihashi Y.: Studies on personal identification by means of lip prints.Forensic Sci.3:233-2248, 1974
  4. Suzuki H., Tsuchihashi Y: Two criminal cases of lip print. Acta Crim.Japonica 36(3): 88-102, 1970
  5. K.Suzuki, from Forensic Odontology and criminal investigation.Acta crim.Japonica 36(3): 88-102
  6. Vahanwala-Parekh, Journal of forensic Medicine & Toxicology Vol 17.No 1,Jan-June,2000:12-17
  7. K.S.Narayan Reddy: The Essentials of Forensic Medicine & Toxicology 21 edition 2002, chapter 4

Vahanwala Sonal
Lecturer, Department of Oral Medicine & Radiology,
Padmashree Dr.D.Y.Patil Dental College & Hospital,
Nerul, Navi Mumbai

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