Tongue activity constitutes a helpful factor in using complete dentures. It has not however been identified, to what extent the force of the tongue can directly stabilize the denture during the occurrence of biting forces. Dislodgement force of the denture held by the patients tongue shows a significant dependence on the tongue strength efficiency, however only few patients are able to analyze the mechanisms of using their tongues to stabilize the denture. The results of the FEM analysis show that the tongue has a strong advantageous influence on denture lateral stability during chewing and also during biting, and a slightly lower ability of counteracting the denture destabilization towards the front. The role played by the tongue in denture retention is not only that it locates the denture by means of tactile sensation but also that it supports the forces counteracting denture dislodgement.