Upper guards do not 'retain/secure' the lower jaw from being driven back into its sockets at the base of the skull. The lower teeth slide on the smooth underside of upper mouth guards or are easily jarred free in an instant from any additional materials added underneath.  Upper guards lack lower channel walls which stabilize the jaw from injurious lateral displacement impacts and helmet focused chin-cup forces.  Brain-Pad's patented Dual-arch technology positions, secures, & cushions the otherwise vulnerable jaw, its vital sockets, and most importantly the immediately adjacent regions of the base of the skull.  Upper guards are inferior to dual-arch jaw-joint protection.

The jaw sockets did not evolve to defend against modern day, repetitive focused strikes from punches, kicks, and helmet to helmet, or helmet impacts.  These socket walls are only 1/16 of an inch thick(the thickness of a potato chip). 4 main nerve trunks that serve the body are attached to the back of the socket walls.  Impacts can crack and elongate these thin socket walls which put permanent pressure on, and impede nerve effectiveness.  Impaction of the sockets can transmit the impact energy across the sockets into the base of the skull.  Adjacent vital processes to the jaw-joints are the intricate ear bones, arteries that supply blood to the skull, as well as the entire base of skull region.

No helmet currently mentions jaw-joint protective, nor lower jaw protective features or benefits.  The helmet secures to the head via the chin-cup.  Impacts to the face mask are transmitted to the chin-cup.  All helmets are secured to a movable bone of the body(the jaw) AND this bone is socket'ed to the head at the base of the skull.  The good news is that a Brain-Pad worn in conjunction with a quality helmet creates the most complete safety system for the head, jaw, and base of the skull.  Plus Brain-Pads allow constant breathing even while clenching!