A dental coupling member attached to upper and lower oral appliances to couple the upper and lower oral appliances, and to regulate displacement of the lower oral appliance to rear side when a mouth is closed or opened, comprising: an outer having a cylindrical portion which is a cylindrical member having a through hole, wherein the outer can be attached to one oral appliance of the upper and lower oral appliances; an inner having a rod-shaped insertion portion to be inserted into an interior of the cylindrical portion and slidably held by the outer, wherein the inner can be attached to the other oral appliance of the upper and lower oral appliances; and a stopper adjustably positioned inside the cylindrical portion, wherein the stopper serves to limit a slide width of the rod-shaped insertion portion inside the cylindrical portion by adjustment of its position along the axial direction of the cylindrical portion, and a cylindrical sleeve slidably inserted into an interior of the cylindrical portion, wherein the rod-shaped insertion portion of the inner is slidably inserted into the interior of the cylindrical sleeve thereby held by the outer, wherein the cylindrical portion has small diameter portion in which an opening diameter of through hole is reduced at the insertion side end portion, the cylindrical sleeve has an increased diameter portion, and the increased diameter portion restricts sliding of the cylindrical sleeve by abutting the small diameter portion of the cylindrical portion, and thereby inhibits detachment of the cylindrical sleeve from the outer; wherein the cylindrical sleeve has a small diameter portion, the rod-shaped insertion portion of the inner has a protrusion, and the protrusion restricts sliding of the inner by abutting the small diameter portion of the cylindrical sleeve, and thereby inhibits detachment of the inner from the cylindrical sleeve; and wherein the inner has an attachment portion which is attached to the other oral appliance, and the attachment portion is disposed in the same straight line as the direction in which the rod-shaped insertion portion extends; wherein the position of the stopper inside the cylindrical portion is adjustable and serves to limit the slide width of the rod-shaped insertion portion by limiting the slide width of the cylindrical sleeve inside the cylindrical portion. an outer having a cylindrical portion which is a cylindrical member having a through hole, wherein the outer can be attached to one oral appliance of the upper and lower oral appliances; an inner having a rod-shaped insertion portion to be inserted into an interior of the cylindrical portion and slidably held by the outer, wherein the inner can be attached to the other oral appliance of the upper and lower oral appliances; and a stopper adjustably positioned inside the cylindrical portion, wherein the stopper serves to limit a slide width of the rod-shaped insertion portion inside the cylindrical portion by adjustment of its position along the axial direction of the cylindrical portion, and a cylindrical sleeve slidably inserted into an interior of the cylindrical portion, wherein the rod-shaped insertion portion of the inner is slidably inserted into the interior of the cylindrical sleeve thereby held by the outer, wherein the cylindrical portion has small diameter portion in which an opening diameter of through hole is reduced at the insertion side end portion, the cylindrical sleeve has an increased diameter portion, and the increased diameter portion restricts sliding of the cylindrical sleeve by abutting the small diameter portion of the cylindrical portion, and thereby inhibits detachment of the cylindrical sleeve from the outer; wherein the cylindrical sleeve has a small diameter portion, the rod-shaped insertion portion of the inner has a protrusion, and the protrusion restricts sliding of the inner by abutting the small diameter portion of the cylindrical sleeve, and thereby inhibits detachment of the inner from the cylindrical sleeve; and wherein the inner has an attachment portion which is attached to the other oral appliance, and the attachment portion is disposed in the same straight line as the direction in which the rod-shaped insertion portion extends; wherein the position of the stopper inside the cylindrical portion is adjustable and serves to limit the slide width of the rod-shaped insertion portion by limiting the slide width of the cylindrical sleeve inside the cylindrical portion.