A dental appliance for treating sleep apnea is disclosed. The appliance may include upper and lower portions and at least one biasing member. The upper portion may comprise a first base and a first feature. The first base may engage the upper teeth of a patient. The first feature may secure to an anterior area of the first base and comprise a concave surface forming a concavity. The lower portion may comprise a second base and a second feature. The second base may engage the lower teeth of the patient. The second feature may secure to an anterior area of the second base and comprise a protrusion. As the patient bites down, the protrusion may contact the concave surface at a point of contact that is a sole or initial contact between the upper and lower portions. Thus, the interaction of the protrusion and concave surface may control certain mandibular loadings and motions of the patient. The biasing member connect the upper portion to the lower portion and urge the lower portion toward the upper portion and in an anterior direction, which may tend to open an airway of the patient.
