PROBLEM TO BE SOLVED: To provide an oral hygiene device which can contribute to an increase in workability of coupling and separation of a device body and a functional part.SOLUTION: An oral hygiene device includes: a toothbrush attachment 50 which is a functional part; a toothbrush body which is a device body including a body case 11 and a gripping case 70; and a toothbrush coupling structure including an outer side fitting part and a toothbrush side fitting part. The body case 11 includes an inner case 30 and an outer case 20. The toothbrush attachment 50 is attachable to an upper part coupling part 21 of the outer case 20 and includes a rotational coupling structure which can be coupled to and separated from a second outer case having a different structure from the outer case 20. The rotational coupling structure enables the coupling and separation of the toothbrush attachment 50 and the second outer case by relatively rotating them about a rotational axis in a longitudinal direction of the toothbrush attachment 50.SELECTED DRAWING: Figure 3
