similar to fingerprints , the pattern of wrinkles on the lips also has individual characteristics . numerous elevations and depressions that form a characteristic pattern on the external surface of lip are referred to as lip prints . lip prints are easily obtained at the crime scene from various materials such as clothing , cups , glasses , cigarettes , doors , etc . they also possess furrows that can be classified into various types for identification of an individual . in 1902 , r. fischer , an anthropologist , first described the biological phenomenon of systems of furrows on the red part of human lip . use of lip prints in personal identification and criminalization was first recommended by edmond locard . he proved in an investigation that the characteristics of lips formed by lip grooves are as individually distinctive as the ridge characteristics of finger prints . until 1950 , however , anthropology merely mentioned the existence of the furrows on the lip prints . two japanese scientists , y. tsuchihashi and t. suzuki ( 19681971 ) , carried out a research on 1364 persons at the department of forensic odontology at tokyo university . it was established that the arrangement of lines on the red part of human lips is individual and unique for each human being . the lip prints are classified as follows : 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- the grooves do not fall into any of the types i  iv and can not be differentiated morphologically . types i , i , and ii are predominant in females and types iii , iv , and v in males . the lip prints are classified as follows : 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- the grooves do not fall into any of the types i  iv and can not be differentiated morphologically . types i , i , and ii are predominant in females and types iii , iv , and v in males . the study population consisted of 200 first to final year bds students of k. d. dental college and hospital , mathura , uttar pradesh , india . all the subjects ( females = 100 , males = 100 ) belonged to the age group of 1726 years . ethical clearance for conducting the study was obtained from the ethical committee of k. d. dental college prior to the start of the study . before data collection , the purpose and procedure of the study were thoroughly explained to the subjects . also , a written informed consent was obtained from each subject . those students who were present at the time of study and who were free from any lesions on their lips were included in the study . subjects with any lip anomalies or any lesions on the lips , those with any known allergy to lip stick , and those who were not willing to participate were excluded from study . dark - colored , non - glossy , less moisture containing lip stick was used to obtain the lip prints of the subjects . after cleaning the surface of the lip , the lip stick was allowed to settle for a minute , after which a transparent cellophane tape slightly larger than the thickness of the lip was uniformly and gently applied to the lip from right to left . all the lip prints were collected by one assistant who coded all the prints and kept in record the name and sex of the respective individual . however , the sex of lip prints was not disclosed to the examiner , so as to reduce the errors while interpreting the results of the study . the pattern of lip prints was studied quadrant wise [ figure 1 ] by using a magnifying lens by one examiner . patterns of lip prints were classified according to the classification given by suzuki and tsuchihashi . the results obtained were later on verified from the coded data collected by the assistant . lip print division quadrant wise the length and thickness of the lips were measured using standard sliding calipers . length of the lip was measured between the outermost visible points on the lip print at the angle of the mouth . thickness of the lip was measured for the upper and lower lips in the midline . chi - square test was used to analyze the lip print patterns in this study . in our study , 78% male lip prints and 84% female lip prints were diagnosed correctly by the examiner [ figure 2 ] . overall , 162 ( 81% ) were diagnosed correctly and 38 ( 19% ) were diagnosed wrong [ figure 3 ] . accuracy of gender determination by the examiner overall accuracy of cheiloscopy in gender determination the most common lip patterns found in males were type iii and type iv ( 20% each ) , followed by type v ( 18% ) , type i ( 12% ) , type i , type ii , and mixed type ( 10% each ) , as compared to females where the commonest patterns were type i and type i ( 25% each ) , followed by type ii ( 17% ) , type iii and type iv ( 10% ) , mixed type ( 8% ) , and type v ( 5% ) . when the lip print patterns were compared , a statistically significant difference was found between males and females ( p  0.05 ) [ table 1 ] . distribution of lip print pattern types in both males and females the most common types of lip prints observed in males were as follows : quadrant a , type iii ( 8% ) ; quadrant b , type iv ( 5% ) ; quadrant c , type iv ( 5% ) ; and quadrant d , type iii and type v ( 5% each ) [ table 2 ] . quadrant wise distribution of different types of lip prints in males the most common types of lip prints observed in females were as follows : quadrant a , type i ( 8% ) ; quadrant b , type i ( 8% ) ; quadrant c , type i ( 7% ) ; and quadrant d , type i , type i , and type ii ( 4% each ) [ table 3 ] . quadrant wise distribution of different types of lip prints in females regarding the thickness of lip prints in males , the average thickness of the upper lip was 13.3 mm as compared to 9.5 mm in females ; the average difference between males and females was 3.8 mm for the upper lip . the maximum and minimum thicknesses of the upper lip in males were found to be 18.9 mm and 12.5 mm , respectively . in females , the maximum and minimum thicknesses of the upper lip the average thickness of the lower lip in males was 14.0 mm as compared to 11.1 mm in females , and the average difference between males and females was 2.9 mm for the lower lip . the maximum and minimum thicknesses of the lower lip in males were 16.9 mm and 11.5 mm , respectively . in females , the maximum and minimum thicknesses of the lower lip were 15.4 mm and 6.9 mm , respectively . cheiloscopy has been proven to be a reliable technique to establish the correct identity of a person . absence of population - specific and gender - specific data can hamper its application as evidence . hence , analysis and testing of such data in various population groups has become absolutely essential . in our study , 78% males and 84% females were diagnosed correctly by the examiner , in comparison to a study done by dongarwar et al . overall , in our study , out of 200 participants , 81% participants were diagnosed correctly , compared to the studies of bajpai et al . and sharma et al . this proves that cheiloscopy is a unique method for identification of sex . in the present study , the most common lip print patterns found in males were types iii and iv ( 20% each ) . in which type i pattern was the most common among males and in the study of malik et al . however , the studies conducted by arif et al . , sheetal et al . , and kautilya et al . showed that the most common patterns found in males were types iv , v , and iii , respectively . however , the most common lip patterns found in females examined in the present study were type i and type i ( 25% each ) . similarly , malik and goel also reported that type i and type i were the most common patterns in females , while in the study done by kautilya et al . , the most common pattern found was type i ( 30% ) . in the study conducted by kapoor and tiwari , type iii pattern was most frequently present in both males and females . a statistically significant difference ( p  0.05 ) in lip print patterns between males and females was found in the study done by xu et al . and gondivakar et al . , which is in accordance with our study . in our study , type iii was the most common in quadrant a among males and types i and i were the most common in quadrants a , b , and c among females . in the study done by amith et al . , type i was the most predominant pattern in the first and second quadrants . however , in the study conducted by verghese et al . , type iv pattern was found to be the most predominant pattern in the middle portion of the upper lip . the present study revealed the average thickness of the upper lip was 13.3 mm as compared to 9.5 mm in females . the average thickness of the lower lip in males was 14.0 mm as compared to 11.1 mm in females . a difference of about 3.8 mm in the lip thickness of upper lip and about 2.9 mm in the lip thickness of the lower lips between males and females were seen . male lips were found to be thicker as compared to female lips . also , in the study conducted by kautilya et al . male lip prints were thicker than female lip prints and this finding could be helpful to differentiate the sexes . limitations of the study were that since the lip print was produced with a substantially mobile portion of the lip , the same person can produce different lip prints according to the pressure , direction , and method used in taking the print . the existence of some pathological conditions ( lymphangiomas , congenital lip fistula , syphilis , lip cheilitis , etc . ) can invalidate the cheiloscopic study . using the lip print pattern for identification of a person is one of the unique practices . male lips were found to be thicker as compared to female lips in our study . therefore , lip print pattern can be used as one of the weapons for personal identification of an individual .
aim : to determine the sex of an individual from the configuration of lip prints.materials and methods : this study was conducted on 200 first to final year bds students of k. d. dental college and hospital , mathura , uttar pradesh , india . 
 all the subjects ( females = 100 , males = 100 ) belonged to the age group of 1726 years . 
 non - glossed lip stick color , white bond paper , cellophane tape , scissors , and magnifying lens were used for identification . 
 length and thickness of the upper and lower lips were measured with sliding calipers . 
 for all the lip prints , the thickness of the lip was measured at the center of the lip.results:overall accuracy by the examiner was found to be 81% ( out of 200 participants , 162 were diagnosed correctly ) and distribution of lip patterns showed a statistically significant difference between the genders ( p  0.05 ) . for the upper lip , the average difference in lip thickness found between males and females was 3.8 mm . 
 however , the average difference for the lower lip between males and females was 2.9 mm.conclusion:in the present study , the lip prints of the subjects did not match with each other . 
 the study reveals that lip prints behold the potential of determination of the sex of the person .