The “memory theory of oral psychosomatic disorder （PSD）”2, 3） proposed by the author in 2016 conjectures that the subjective symptom of oral PSD is the retrieved memory of the original dental disease experienced in the past. This article reconsiders the theory through abduction, one of the inferences. Based on this theory, the following suppositions are made: 1） The memory of the subjective symptom of the original dental disease is stored as an engram in the cerebral cortex and retrieved upon activation of the engram. 2） The symptom is reinforced and conditioned with aversion experiences （such as trouble with family, work-related problems, complaints about dental treatment, and so on）. 3） The chronicity of the symptom is explained as long-term memory. 4） The effects of psychological and antidepressant therapy are based on overwriting of the aversion memory with new information and reinforcement thereof. 5） Oral PSD is a single disease and its type is only a label without entity.