A contour-adjustable toothbrush is a device that provides a more thorough brushing experience while eliminating the need to remove the device from the mouth during brushing. A first brushing assembly and a second brushing assembly are slidably engaged into a housing handle that may be grasped by the user. The first brushing assembly and the second brushing assembly each include a flexible brush head with a concave surface. The concave surface of the first brushing assembly is oriented away from the concave surface of the second brushing assembly, enabling the first brushing assembly and the second brushing assembly to clean the upper teeth and lower teeth simultaneously. The first brushing assembly and the second brushing assembly are independently adjustable in order to adjust the length of the device. An electronic variant of the device includes a power supply and at least one actuator.
