Morphometric Analysis of Tongue in Individuals of European and African Ancestry

The maxillary dental arch is generally preserved due to its relatively protected location, as well as due to the strength of the teeth because of cadaveric spasm. However, when the victim is edentulous, or when there are not enough comparative data to effectively analyze the dental arches, human identification information based on forensic dentistry methods is very limited. Therefore, since the tongue is an organ of easy access and presents resistance to decomposition and carbonization because it is located in a humid closed cavity, it has become an important organ in post-mortem evaluation. The objective of study was to compare the human tongue dimensions and collagen percentage according to ancestry, gender and age groups. Forty-five tongues were removed during autopsy performed between 1 and 8 hours after death and immediately fixed in formaldehyde in order to avoid decomposition. The tongue length, width and thickness of autopsied individuals were analyzed. Collagen percentage was determined using AxioVision software on slides stained with Picrosirius. The subjects were classified according to gender, age, and ancestry.The tongues length of African ancestry individuals were significantly longer than European ancestry tongues (p = 0.02). The European descendants showed significantly higher collagen percentage than the African descendants (p = 0.01). There was no significant difference regarding collagen percentage between gender groups or age groups. There were also no significant differences in tongue thickness and width according to the ancestry, gender or age groups. This study is the first to compare the size and collagen percentage of the human tongue between different gender, ethnic and age groups. In conclusion the African ancestry individuals were significantly longer and the European ancestry tongues had a higher collagen percentage. Therefore we suggested that tongue length and collagen percentage analysis could be used as additional parameter for human identification, especially in cases of quartering or even in high-impact accidents where isolated parts of the human body can be found far from the site of the murder or accident. However, further research are needed to confirm these findings.