dental , fingerprint and dna comparisons are probably the most common techniques used in this context , allowing fast and secure identification processes .
however , in certain circumstances related to the scene of the crime , these techniques might be unavailable , so there is still an increasing need for reliable alternative methods of establishing identity .
the grooves present on the human lips are unique to each person and can be used to determine identity of the individual .
the study of these grooves or furrows present on the red part or the vermilion border of the human lips is known as cheiloscopy .
teeth are extremely durable even at high temperature and may be identified even when the rest of the body has undergone decomposition .
mandibular canines are found to exhibit the greatest sexual dimorphism amongst all teeth.[57 ]  sexual dimorphism  refers to those differences in size , stature , and appearance between male and female that can be applied to dental identification because no two mouths are alike .
the authors developed an index , which they named mandibular canine index ( mci ) .
the purpose of the study was to investigate the accuracy with which gender can be differentiated by using cheiloscopy and mci .
a study sample comprised 60 students of teerthanker mahaveer dental college and research centre , 30 males and 30 females aged between 20 and 25 years .
cheiloscopy and mci both were performed in each student to investigate the accuracy of both the sex determination parameters .
lips free from any pathologyabsolutely normal transition zone between the mucosa and the skinindividuals with known hypersensitivity to lipstick were not included in this study 
  lips free from any pathology absolutely normal transition zone between the mucosa and the skin individuals with known hypersensitivity to lipstick were not included in this study a dark colored lipstick was applied with the single stock , evenly on the vermillion border .
the subject was asked to rub both the lips , to spread the lipstick evenly .
after 2 mins , lip impressions were made , on a strip of cellophane tape on glued portion , which was then stuck to a white bond paper .
the lip prints were classified ( tsuchihashi 's classification ) in the year 1974 into six types , according to the shape and course of grooves : type i : clear - cut grooves running vertically across the lip type i ' : the grooves are straight but disappear half - way instead of covering the entire breadth of the lip .
type ii : the grooves fork in their course type iii : the grooves are branched type iv : the grooves are of criss crossed pattern and reticular type v : the grooves do not fall into any of the types i to iv and can not be differentiated morphologically subjects with following status of teeth were included in the study . 

healthy state of gingiva and periodontiumcaries free teethnormal over - jet and overbiteabsence of spacing in the anterior teethnormal molar and canine relationship 
  healthy state of gingiva and periodontium normal over - jet and overbite absence of spacing in the anterior teeth normal molar and canine relationship impressions were made by alginate and study models were prepared in dental stone .
the following measurements were taken for all the subjects using a digital vernier 's callipers .
mandibular canine width was measured as the greatest mesiodistal dimension of mandibular canine on either side of the jaw using a vernier calliper , and the average of this was taken .
the intercanine distance was measured as the linear distance between the cusp tips of right and left mandibular canine . the observed mandibular canine index ( mcio )
was calculated using the formula below : the standard mci value is used as a cut- off point to differentiate males from females , which is obtained from the measurements taken from the samples by applying the following formula : the observed mci was compared with the observed mci value obtained in this study and correlated with previous studies like reddy lvk , rao et al .
a study sample comprised 60 students of teerthanker mahaveer dental college and research centre , 30 males and 30 females aged between 20 and 25 years .
cheiloscopy and mci both were performed in each student to investigate the accuracy of both the sex determination parameters .

 lips free from any pathologyabsolutely normal transition zone between the mucosa and the skinindividuals with known hypersensitivity to lipstick were not included in this study 
  lips free from any pathology absolutely normal transition zone between the mucosa and the skin individuals with known hypersensitivity to lipstick were not included in this study a dark colored lipstick was applied with the single stock , evenly on the vermillion border .
the subject was asked to rub both the lips , to spread the lipstick evenly .
after 2 mins , lip impressions were made , on a strip of cellophane tape on glued portion , which was then stuck to a white bond paper .
the lip prints were classified ( tsuchihashi 's classification ) in the year 1974 into six types , according to the shape and course of grooves : type i : clear - cut grooves running vertically across the lip type i ' : the grooves are straight but disappear half - way instead of covering the entire breadth of the lip .
type ii : the grooves fork in their course type iii : the grooves are branched type iv : the grooves are of criss crossed pattern and reticular type v : the grooves do not fall into any of the types i to iv and can not be differentiated morphologically

 lips free from any pathologyabsolutely normal transition zone between the mucosa and the skinindividuals with known hypersensitivity to lipstick were not included in this study 
  lips free from any pathology absolutely normal transition zone between the mucosa and the skin individuals with known hypersensitivity to lipstick were not included in this study a dark colored lipstick was applied with the single stock , evenly on the vermillion border .
the subject was asked to rub both the lips , to spread the lipstick evenly .
after 2 mins , lip impressions were made , on a strip of cellophane tape on glued portion , which was then stuck to a white bond paper .
the lip prints were classified ( tsuchihashi 's classification ) in the year 1974 into six types , according to the shape and course of grooves : type i : clear - cut grooves running vertically across the lip type i ' : the grooves are straight but disappear half - way instead of covering the entire breadth of the lip .
type ii : the grooves fork in their course type iii : the grooves are branched type iv : the grooves are of criss crossed pattern and reticular type v : the grooves do not fall into any of the types i to iv and can not be differentiated morphologically
healthy state of gingiva and periodontiumcaries free teethnormal over - jet and overbiteabsence of spacing in the anterior teethnormal molar and canine relationship 
  healthy state of gingiva and periodontium normal over - jet and overbite absence of spacing in the anterior teeth normal molar and canine relationship impressions were made by alginate and study models were prepared in dental stone .
the following measurements were taken for all the subjects using a digital vernier 's callipers .
mandibular canine width was measured as the greatest mesiodistal dimension of mandibular canine on either side of the jaw using a vernier calliper , and the average of this was taken .
the intercanine distance was measured as the linear distance between the cusp tips of right and left mandibular canine . the observed mandibular canine index ( mcio )
was calculated using the formula below : the standard mci value is used as a cut- off point to differentiate males from females , which is obtained from the measurements taken from the samples by applying the following formula : the observed mci was compared with the observed mci value obtained in this study and correlated with previous studies like reddy lvk , rao et al .
healthy state of gingiva and periodontiumcaries free teethnormal over - jet and overbiteabsence of spacing in the anterior teethnormal molar and canine relationship 
  healthy state of gingiva and periodontium normal over - jet and overbite absence of spacing in the anterior teeth normal molar and canine relationship impressions were made by alginate and study models were prepared in dental stone .
the following measurements were taken for all the subjects using a digital vernier 's callipers .
mandibular canine width was measured as the greatest mesiodistal dimension of mandibular canine on either side of the jaw using a vernier calliper , and the average of this was taken .
the intercanine distance was measured as the linear distance between the cusp tips of right and left mandibular canine . the observed mandibular canine index ( mcio )
was calculated using the formula below : the standard mci value is used as a cut- off point to differentiate males from females , which is obtained from the measurements taken from the samples by applying the following formula : the observed mci was compared with the observed mci value obtained in this study and correlated with previous studies like reddy lvk , rao et al .
the table 1 shows that the overall mesio - distal width of mandibular canine was found to be 6.57  0.29 mm among the study group in which males had a more mesio - distal width in both right ( 6.79  0.29 ) and left ( 6.78  0.30 ) mandibular canines when compared to females and was found to be significant ( p = 0.000 , hs ) .
the observation was similar for the mandibular inter - canine distance also with maximum intercanine distance ( 32.89  1.29 ) in males which was found to be significant ( p = 0.000 , hs ) when compared to females ( 30.6  1.39 ) .
there is no variation in mci of males and females and was found to be not significant in the present study group .
overall mesio - distal width table 2 shows that type i ( 46.7% ) lip print was most commonly seen in females followed by type ii ( 30.0% ) , type iv ( 16.7 ) , type iii ( 3.3% ) , and type v ( 3.3% ) , respectively .
type iii ( 43.3% ) was seen most commonly in males followed by type iv ( 30.0% ) , type ii ( 13.3% ) , and type i ( 6.7% ) , and v ( 6.7% ) , respectively .
this relation of gender propensity to type of lip print distribution was found to be significant with a likelihood ratio of 25.8 .
distribution and comparison of lip print with gender table 3 reveals that right mandibular canine shows more sexual dimorphism as compared to mandibular left canine .
sexual dimorphism in mandibular canines in table 4 , there was not much of difference in the mesio - distal width of mandibular canines on both right and left side among different types of lip print patterns and was found to be significant and the variation was present between type 1 and type 3 lip print pattern as confirmed by the bonferroni 's post hoc test ( 0.025 , s ) where in the type 1 ( 6.43  0.26 ) and type 3 ( 6.82  0.33 ) lip print pattern subjects had a varied mesio - distal distance .
however , the mean mci and inter canine distance with lip print patterns were found to be non - significant and their mean values did not vary much among different type of lip prints .
human identification has always been of paramount importance to society . noting , as providing an additional tool for personal identification is the series of studies on the morphology of the lips and the pattern produced when they are impressed onto a variety of surfaces .
the lip prints were classified using the classification proposed by suzuki and tsuchihashi in 1974 , also known as tsuchihashi 's classification .
it was found to have a clear description of nearly all of the commonly encountered lip patterns and was easy to interpret .
the fact that a minimum number of type v patterns were observed in the present study was evidence to the complete coverage of patterns in this classification . in our study , the upper lip showed a predominance of type i pattern ( 26.7% ) followed in order by type iii ( 23.3% ) and type iv ( 23.3 ) , type ii ( 21.7% ) and type v ( 5.0% ) .
( 2001 ) stated that the uniqueness of patterns depended on the way the lip muscles relaxed to produce a particular pattern .
lvque and goubanova ( 2004 ) suggested that the furrows and grooves on the lips seemed to be privileged routes for saliva to spread over the lips and maintain good hydration .
the variations in pattern between the upper and lower lip may be attributed to these factors and might have a functional significance .
lvque and goubanova also noted that some continuity appeared to exist between the lips and adjacent skin lines and suggested a common origin .
as early as 1950 , snyder suggested that the normal lines and fissures of the lips were an individual characteristic , much the same as finger ridges.[81216 ] since then , numerous studies give evidence to the fact that lip prints are unique and characteristic of an individual .
however , at the initial classification stage , as in the case of fingerprints , there are similarities among the broadly classified groups of lip prints .
these differences are probably related to their function , which is different on an evolutionary basis from other teeth .
although canine sex differences and enhanced canine survival are not related to each other , both are probably related to the need for successful use of canines as weapons for total body survival .
the present study establishes the existence of a definite statistically significant sexual dimorphism in mandibular canines .
this is consistent with the findings of hashim and murshid who conducted a study on 720 saudi males and females in the age group of 13 - 20 years .
similar findings were given by lew and keng in their study on an ethnic chinese population with normal occlusions .
a study by kaushal et al . found a statistically significant dimorphism in the mandibular canines in 60 subjects in a north indian population , where the mandibular left canine was seen to exhibit greater sexual dimorphism .
they also concluded that if the width of the canine is greater than 7 mm , the probability of the sex of the person under consideration being male was 100% .
the emerging field of forensic odontology in india relies a lot on inexpensive and easy means of identification of persons from fragmented jaws and dental remains .
it is in such situations that the dentist can be called upon to render expertise in forensic science .
the present study establishes the existence of a definite , statistically significant , sexual dimorphism in mandibular canines as well as cheiloscopy .
we conclude that the standard mci is a quick and easy method for sex identification .
this is of particular significance when more advanced methods for sex determination are not readily available . however , as the accuracy of mci in identification of sex has never exceeded 87.5% , it can only be used as a supplemental tool .
 introduction : establishment of a person 's individuality is important for legal as well as humanitarian purpose and gender determination is an essential step in identifying an individual . in forensic odontology 
 the sum total of all the characteristics of teeth and their associated structures provide a unique totality and forms the basis for personal identification.aims and objectives : to investigate the accuracy of various methods employed in sex determination such as cheiloscopy and mandibular canine index ( mci).materials and methods : the study group comprises adults between 20 and 25 years of age , who were assessed for gender identification using lip prints and mci . 
 the results were subjected to statistical analysis.results:mci and lip prints were found to be accurate and specific for sex determination.conclusion:there is scope for use of these methods in criminal investigations , personal identification , and genetic studies . 
 thus , dental tissues make good witnesses although they speak softly , they never lie and they never forget . 
Introduction
Materials and Methods
Study sample
For cheiloscopy
Inclusion/Exclusion criteria
For Mandibular Canine Index
Inclusion criteria
Results
Discussion
Conclusion