A dental appliance having increased or decreased thickness between an upper shell and a lower shell in combination with a hinging mechanism and a system and a method for treating malocclusions are provided. The dental appliance may have an upper shell and a lower shell which receive upper teeth and lower teeth, respectively, of a user. The upper shell and the lower shell may be attached at a hinge. The dental appliance may have an increased thickness between the upper shell and the lower shell as well as an increased thickness of the hinge. In an embodiment, the dental appliance may have a decreased vertical thickness and an insertable hinging mechanism. The dental appliance may then extend treatment of malocclusions to the rear teeth of the user and may correct a dental condition, such as, for example, overbite, overjet, open bite, crowding, rotations, spacing, cross-bites, gummy smiles and temporomandibular joint problems.