A denture that shifts easily in response to latterally applied forces can cause a disruption in the border seal or prevent the denture base from Correctly relating to the supporting tissue. The factors that Contribute to stability include ridge height and conformation, base adaptation, residual ridge relationships, occlusion harmony, and Muscle control. These factors can be condensed into the following categories; 1. The relationship of the denture base to the underlying tissue. 2. The relationship of occlusal harmony. 3. The relationship of the denture surface and border to the surrounding muscle. 4. The location of artificial tooth.