Abstract: An improved manual oral cavity expansion device comprising a fixing element with one end connected with a first holding element, and another end forming an accommodating portion protrudingly disposed with a pivoting portion; at least one linkage element disposed on the fixing element; a rotating element accommodated in an accommodating space of the accommodating portion and sleeved on the pivoting portion; a movable element with one end connected with a second holding element, and another end forming a movable portion correspondingly disposed in the accommodating space and sleeved on the pivoting portion; and an expansion unit. An outer circumference of the rotating element is arranged with a plurality of tooth elements in a row, and one end of the linkage element contacts the tooth elements. The expansion unit has a first expansion arm connected to the accommodating portion and a second expansion arm connected to the movable portion.

Abstract: An improved manual oral cavity expansion device comprising a fixing element with one end connected with a first holding element, and another end forming an accommodating portion protrudingly disposed with a pivoting portion; at least one linkage element disposed on the fixing element; a rotating element accommodated in an accommodating space of the accommodating portion and sleeved on the pivoting portion; a movable element with one end connected with a second holding element, and another end forming a movable portion correspondingly disposed in the accommodating space and sleeved on the pivoting portion; and an expansion unit. An outer circumference of the rotating element is arranged with a plurality of tooth elements in a row, and one end of the linkage element contacts the tooth elements. The expansion unit has a first expansion arm connected to the accommodating portion and a second expansion arm connected to the movable portion.

Abstract: An improved hand tool with molar as resistance point comprises a holding unit, a pivoting unit, an expansion unit and a clean jacket. The holding unit has a first end and a second end. The first end is provided for holding by a user, and the pivoting unit is pivotally connected to the second end correspondingly. A butt end and a connection end are respectively formed at two ends of the expansion unit, the butt end correspondingly butts a plurality of molars of the user, the connection end is pivotally connected to the pivoting unit correspondingly, and the clean jacket is correspondingly sleeved on the expansion unit.