"Flabby" maxillary ridges and "atrophied or flat" mandibular ridges pose significant problems for the provision of stable and retentive dental prostheses for affected patients. Problems arise during the act of impression making, and stability of the lower denture is rather difficult to achieve. The purpose of this paper is to review the impression techniques that can be used to optimize the treatment of edentulous patients with resorbed and unresorbed mandibular ridges, especially for those where the stability of the lower denture is the decisive factor between success and failure.