An intra-oral device used for people that snore or have sleep apnea is designed to move a users lower jaw forward relative to the users immovable upper jaw and to prevent the users mouth from inadvertently opening while sleeping. The device includes upper and lower appliances fitted to the users respective upper and lower dental arches. The lower appliance possesses a partially embedded bracket. An adjustment element is integrated into the upper portion of the bracket. With the users mouth closed and the upper and lower appliances positioned over the users respective dental arches, the adjustment element is moved rearward by worm action into load bearing contact against the forward facing immovable vertical contact wall of the upper appliance. This action moves the lower appliance forward, and thus, the users lower jaw with its anatomically attached tongue are also moved forward relative to the mouth which in turn opens the users airway. Also, a forward facing horizontal shoulder positioned at the lowest portion of the vertical contact wall acts against the adjustment element to prevent the users mouth from opening while sleeping.
