Cheiloscopy is recognized as a tool for personal identification due to its strength in criminalistics. In this study, the lip print of Malaysian Chinese population in Klang Valley was used for gender determination using lipstick-cellophane technique. 412 subjects (203 males and 209 females) were selected conveniently. Lipstick was first applied on the lips and the lip print was lifted using cellophane tape prior to pasting them onto a plain A4 paper and analysis using magnifying glass. Six topography areas of lip prints were classified using Suzuki and Tsuchihashi’s classification, including upper left, upper middle, upper right, lower right, lower middle and lower left. Chi-square test showed that all lip sections were significantly different from each other (p < 0.05). Type II was the dominant pattern in four lip sections for both genders: upper left (male 81.3%, female 57.4%), upper right (male 71.9%, female 42.9%), lower left (male 98.0%, female 90.0%) and lower right (male 96.1%, female 86.1%). Type IV was the dominant pattern for both middle part of the lips; upper middle (male 56.2%, female 50.7%) and lower middle (male 62.6%, female 50.2%). The results showed that gender can be differentiated based on lip print patterns. This finding suggested that cheiloscopy could be used in aiding personal identification for forensic investigation.
Individual identification is an important and challenging task in forensic investigation. Lip print on drinking glass or cigarette butt found at crime scenes may link to a suspect. The aim of this study was to determine the differences in lip print between sexes or races, differences in lip measurement between sexes or races and determine a way to estimate sex and race by using lip print or lip measurements for main races in Malaysia. A total of 134 subjects (67 males and 67 females) of Malay, Chinese and India were recruited from Universiti Kebangsaan Malaysia Campus Kuala Lumpur (UKMKKL), Malaysia. Lip prints were taken by using a lipstick and a transparent cellophane tape. Lip measurements were taken by using electronic digital callipers. Lip prints were classified according to Tsuchihashi classification. Statistical analysis indicated that there was a significant difference in lip print between sexes (p < 0.001) but not in races (p > 0.05). Width of oral opening and the height of lower lip both indicated significant differences between sexes (p < 0.001) while the height of upper lip and lower lip each indicated significant differences between races (p < 0.05). However, there was no significant interaction between sexes and races for all lip measurements. Formulae for sex and race determination were calculated with Classification Tree when there was significant difference between every comparison. Tables of accuracy percentage and performance evaluation for method in categorizing sex or race by using lip print or lip measurement were made. For validation of method in sex determination based on the formulae formed, accuracy in females is 90% and 65% in males. Therefore, overall percentage of accuracy in sex determination was 77.5%. This study can provide a preliminary idea about the use of lip prints in sex or race determination among Malaysian population.