Aim: To determine whether there is sexual dimorphism of lip prints’ morphological features in the Croatian population and to provide a scoping review for the accuracy of sex estimation on lip prints.
Methods: The study on the Croatian population included 88 male and 88 female (median age 25, range 18 - 50) participants. Lip prints were analyzed by quadrant, and then the predominant pattern on the entire lip was observed. A systematic search of the relevant bibliographical databases was conducted, including Medline, Scopus, Web of Science Core Collection (WoSCC), and Cinahl (October 23rd, 2020). OpenGrey, Open Science Framework, and Science.gov databases were searched for grey literature. Findings were reported in the narrative form in accordance with the PRISMA Extension for Scoping Reviews (PRISMA-ScR) checklist. A total of 80 studies were included.
Results: The study of sexual dimorphism of lip prints in the Croatian population showed that there were no statistically significant differences between males and females; and when all quadrants were considered together (χ2 = 3.625, P = 0.459), sex could be estimated for only 55.7% of persons. Twenty-nine studies (36.3%) did not find differences between males and females, and 34 (42.5%) found sexual dimorphism only in some of the lip parts and some quadrants. The assessment of examined studies showed that only six studies met all quality criteria.
Conclusion: There is no forensically significant sexual dimorphism in lip prints in the Croatian population. The scoping review showed that sex estimation using lip prints should not be used as evidence in court as the present methodology is not reliable and the potential rate of error is unknown.