Analysis of rapid maxillary molar distal movement without patient cooperation.

The purpose of this investigation was to evaluate the treatment effects of an intraoral appliance used for rapid distal movement of the maxillary molars. The appliance studied, the Jones jig, is designed to deliver a distalizing force to the maxillary molar against an intraoral anchorage unit thereby eliminating the need for patient compliance. A retrospective study was performed comparing before and after lateral cephalometric radiographs on 13 patients who were treated for an average of 26 weeks with the Jones jig. The cephalometric radiographs were evaluated to determine if there were significant differences between pretreatment and posttreatment variables that included skeletal, dental and soft tissue relationships. Differences between the pretreatment and posttreatment means were significant for mesial angulation of the premolar anchorage unit (P <.001), distal movement of the maxillary molars (P <.01), mesial movement of the premolar anchorage unit (P <. 01), mesial movement of the maxillary incisors (P <.001), and increased lower anterior facial height (P <.01). The anchorage loss, flared maxillary incisors, and increased facial height are negative treatment effects that should be expected when using this or similar appliance design.