Abstract— Denture retention by atmospheric pressure is discussed. A potential space which is enclosed by a salivary meniscus exists between a denture base and the oral mucosa. When the denture is dislodged, this space is forced to expand and the meniscus recedes, but the recession is impeded by the viscosity of the saliva and a negative pressure is generated under the denture. During a momentary eccentric contact, the meniscus will not have moved far enough across the ridge to cause tilting on the balancing side and denture displacement can be considered to be essentially displacement of the meniscus.