individual identification is an important and challenging task in forensic investigation , which was based on scientific principles .
tsuchihashi and suzuki established that the arrangement of lines on the red part of the human lip is individual and unique .
the grooves were named as sulci labiorum and corresponding lip prints as  figura linearum labiorum rubrorum  by them . in 1981 , cottone reported cheiloscopy as a special technique for the purpose of individual identification .
a lip print is different in every living individual and does not change with time therefore it can be used as a tool in forensic investigations .
a lip print may be revealed as a stratified surface trace with visible elements of lines , namely the furrows and if the lines are not clear , only the shape of lips is printed .
it has been confirmed that these furrows recover after undergoing alterations like trauma , inflammation , and diseases like herpes .
lip print on drinking glass or cigarette butt found at crime scenes may link to a suspect .
the one of the most emerging methods of human identification , which originates from the criminal and forensic practice , is human lips recognition .
fischer in 1902 was the first anthropologist to describe the furrows on the red part of human lips .
however , it was in 1932 that edmond locard , one of the criminologists recommended the use of lip prints in personnel identification and criminalization .
it is a method of identification of a person based on the characteristic arrangement of lines appearing on the red part of the lips .
cheiloscopy in its present stage of development has surpassed the limits of a method and has become a means of criminalistics identification .
lipstick smears can lead to indirect proof of a relationship or contact between a victim and a suspect or a suspect and a crime scene .
those latent or invisible lip prints can be detected using aluminum powder and magnet powder as mentioned by sharma et al .
the lipstick - cellophane tape method was used in lifting lip print was described first by bindal et al .
the use of lipstick is not inevitable as latent prints are available at all crime scenes because of the presence of minor salivary glands and sebaceous glands .
santos in 1967 classified lip grooves into four types ( straight line , curved line , angled line , and sine shaped line ) .
suzuki and tsuchihashi in 1970 devised a new classification of lip grooves as : 
 type i  a clear cut groove running vertically across the liptype i  partial length groove of type itype ii  a branched groovetype iii 
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  undetermined .
the intercommissural distance ( icd ) in relaxed state is measured between the corners of the mouth .
it corresponds to the width of maxillary anterior teeth and can be used as a guide for the selection of maxillary dental prosthesis .
icd could be utilized in forensic odontology for the identification of a person , if he / she was a denture wearer .
the inter labial gap during relaxed state , can be used to assess the lip competency .
the lip competency records in human beings could be matched with past facial profile photographs or lateral cephalogram records for identification in mass disaster .
thus a dental surgeon has to actively play his role in personal identification and criminal investigation , as his evidence would be very much useful in law and justice .
this study will investigate the correlation of lip print pattern to gender , abo blood groups , and icd in sriganganagar , rajasthan .
the study was conducted on 208 randomly selected students of surendera dental college and research institute , sriganganagar , rajasthan , out of which 123 were females and 85 were males , aged between 18 and 25 years from october 2012 to march2013 .
all the subjects were briefed about the purpose of the study and a written informed consent was obtained .
the subjects undergoing orthodontic treatment , presence of congenital lip abnormalities , inflammation or trauma of lips , hypersensitivity to lipsticks were excluded from the study .
red flamed lip stick , lip brush , cellophane tape ( 45 mm width ) , white a4 bond paper , electronic digital calipers , magnifying glass ( 10 cm diameter ) , anti - a sera , anti - b sera , and anti - rh sera for abo blood group testing .
the lips of the subjects were cleaned and a red lipstick was applied evenly with a single stroke using lip brush over the vermillion border and the subjects were asked to rub both the lips to spread the applied lipstick uniformly .
after 2 minutes , the glued portion of the cellophane tape was placed over the lipstick .
the lip prints were taken in the normal rest position by dabbing in the center first and then pressing it comfortably toward the corners of the lips .
the cellophane strip was then stuck to the white bond paper for a permanent record .
the lip prints were then analyzed following tsuchihashi classification using a magnifying glass by two forensic experts independently [ figure 1 ] .
each lip was divided into six areas starting from right upper area to right lower area ( a1a6 ) .
the type of lip print was assessed in all the six areas and the type , which was repeated the maximum number of times , was considered as described by rajendran and sivapathasundram .
the short upper lip and proclined upper anterior teeth with interlabial gap in relaxed position was noted clinically to record the competency of lips .
the icd ( in cm ) for each subject was recorded at rest position using electronic digital calipers .
type i - vertical groove across the lip , type i-partial length groove , type ii - branched groove , type iii - intersected groove , type iv - reticular pattern , type v - undetermined the blood group of the subjects were identified by placing a drop of blood on the slide and treated with anti - a , anti - b , and then on anti - rh sera .
positive agglutination of the blood on treating with anti - a is considered as blood group a , positive reaction with anti - b is considered as blood group b , if no agglutination is produced then the blood group is o and if agglutination is seen with both antisera then blood group ab is considered .
similarly positive agglutination reaction with rh antigen is considered rh+ or otherwise rh. the results were analyzed using spss 20.0(microsoft corporation inc . , chicago , il , usa ) statistical software .
red flamed lip stick , lip brush , cellophane tape ( 45 mm width ) , white a4 bond paper , electronic digital calipers , magnifying glass ( 10 cm diameter ) , anti - a sera , anti - b sera , and anti - rh sera for abo blood group testing .
the lips of the subjects were cleaned and a red lipstick was applied evenly with a single stroke using lip brush over the vermillion border and the subjects were asked to rub both the lips to spread the applied lipstick uniformly .
after 2 minutes , the glued portion of the cellophane tape was placed over the lipstick .
the lip prints were taken in the normal rest position by dabbing in the center first and then pressing it comfortably toward the corners of the lips .
the cellophane strip was then stuck to the white bond paper for a permanent record .
the lip prints were then analyzed following tsuchihashi classification using a magnifying glass by two forensic experts independently [ figure 1 ] .
each lip was divided into six areas starting from right upper area to right lower area ( a1a6 ) .
the type of lip print was assessed in all the six areas and the type , which was repeated the maximum number of times , was considered as described by rajendran and sivapathasundram .
the short upper lip and proclined upper anterior teeth with interlabial gap in relaxed position was noted clinically to record the competency of lips .
the icd ( in cm ) for each subject was recorded at rest position using electronic digital calipers .
type i - vertical groove across the lip , type i-partial length groove , type ii - branched groove , type iii - intersected groove , type iv - reticular pattern , type v - undetermined the blood group of the subjects were identified by placing a drop of blood on the slide and treated with anti - a , anti - b , and then on anti - rh sera .
positive agglutination of the blood on treating with anti - a is considered as blood group a , positive reaction with anti - b is considered as blood group b , if no agglutination is produced then the blood group is o and if agglutination is seen with both antisera then blood group ab is considered . similarly positive agglutination reaction with rh antigen is considered rh+ or otherwise rh. the results were analyzed using spss 20.0(microsoft corporation inc . , chicago , il , usa ) statistical software .
b positive ,  followed by 29.8% of  o positive ,  about 14.4% of  a positive , 
2.8%b negative ,  and  ab negative ,   a negative  being 0.9% , respectively [ table 1 ] .
gender distribution of blood groups and lip print patterns the results of the two observers were analyzed for lip patterns by wilcoxon signed - rank test showing insignificant inter - observer bias [ figure 2 ] .
frequency of lip print pattern by two observers the general distribution of lip prints in the given population was in the order of branched type ( 47.6% ) followed by intersecting ( 23.1% ) , vertical , partial length groove , reticular , and undetermined type [ table 1 ] .
frequency of type i , type i , typeii and type iii lip prints was more among the b+ group .
distribution of type iv lip prints was equal among a+ and o+ while type v showed increased expression among individuals with a+ blood group [ table 2 ] .
distribution of lip prints with blood groups the correlation was calculated between lip prints and blood groups and also lip prints with gender , both were found insignificant [ table 3 ] .
correlation of lip prints with gender and blood groups out of the total 208 , 198 ( 95.2% ) subjects were having competent lips while 10 ( 4.8% ) were having incompetent lips .
the type ii lip pattern was more common in competent lips while type ii and type iii was more among incompetent lips .
the mean icd of the sample was 4.96 cm , which was more in males ( 5.17 cm ) than females ( 4.83 cm ) .
the mean icd is noted highest among type ii lip pattern subjects [ table 4 ] .
the present study was conducted among 208 randomly selected subjects among which 57.5% were female and 42.5% were male .
the lip pattern of the sample was studied independently by two forensic experts in six areas , that is , a1-a6 , to find out any inter observer bias which was found insignificant by statistical analysis
. the results showed that type ii was the dominant pattern in male and female population .
this was followed by type iii pattern in both gender ( 22.4% in males and 45.5% in females ) .
the results were in accordance with previous studies by sivapathasundram et al . , and manipady .
augustine et al . , stated that the minimum number of type v patterns should be seen in tsuchihashi classification , as in the present study where no type v pattern was seen in female population , while only two male subjects showed the same pattern .
the results revealed no significant correlation between distribution of lip print patterns and abo blood group ( p = 0.71 ) .
there is no statistically observed difference between males and females in individual lip print types ( p = 0.629 ) as was seen in study conducted by neo et al .
the mean icd was found largest among branched lip pattern ( type ii ) subjects while overall mean icd was more among males than females as reported by temitope et al .
the competent lips were noted in 95% of the study population while incompetency of lips was seen only in 5% .
the type ii lip pattern subjects showed maximum competent lips while incompetent lips were equally seen among type ii and type iii lip print pattern subjects .
the study confirmed the distinctiveness of cheiloscopy but disproves any statistical correlation of lip print pattern with gender , abo blood groups , or icd .
 background : in forensics , the mouth allows for a myriad of possibilities . 
 lip print on glass or cigarette butt found at crime scenes may link to a suspect . 
 hence , a dentist has to actively play his role in personal identification and criminal investigation.aims:to investigate the uniqueness of the lip print patterns in relation to gender , abo blood groups and intercommissural distance ( icd).materials and methods : the study was conducted on 208 randomly selected students . 
 the lip print of each subject was obtained and pattern was analyzed according to tsuchihashi classification . 
 the blood group and icd at rest position was recorded for each.results:the study showed that type ii ( branched ) lip pattern to be most prominent . 
 the b+ blood group was the most common in both genders and the icd is higher in males . the lip print pattern does not show any correlation between abo blood groups , gender , and icd.conclusions:the lip print pattern shows no correlation with gender , abo blood groups , or icd . further studies with larger samples are required to obtain statistical significance of this correlation . 
Introduction
Materials and Methods
Study materials
Technique
Results
Discussion
Conclusion