The use of exogenous pulsed electromagnetic fields (PEMF) to stimulate the healing of nonunions and other long bone defects is common in medicine. This investigation used the dog model and image analysis of standardized radiographs to assess loss of residual ridge height following extractions. It demonstrates the effectiveness of intermittent PEMF to reduce the rate of residual ridge resorption. It further suggests there may be a causal relationship between residual ridge resorption and the alteration of endogenous bioelectric signals caused by the loss of teeth.