The researchers believe that tool use could have helped to alter considerably how the ancient members of the human family tree ate and survived, Discovery News reported.
The ancient hominid jaws have also suggested it as over experienced toothpicking, possibly leading to swelling and infection.
Ann Margvelashvili, a paleoanthropologist at the University of Zurich's Anthropological Institute and Museum in Switzerland, said fossil findings in human evolution are often represented by mandibles, because typically they are better preserved than any other parts of the skeleton except teeth during fossilization processes.
Scientists, who analyzed how jawbones from modern hunter-gatherers from Australia and Greenland could vary, compared them with Dmanisi teeth and jaws.
Margvelashvili said that Dmanisi hominids show the first clear case of overusing the toothpick, which led to infection.