Unilateral Maxillary Molar Distalization Appliance Using an Expansion Screw

Objectives: An appliance to correct unilateral Class II molar relationship was described, the clinical and laboratory procedures for the construction of the appliance were explained. The clinical application for the unilateral molar distalization was illustrated by a case report. Other methods of distalizaton were reviewed and compared with the present appliance. The advantages and disadvantages of the appliance were presented. Methods and Materials: The appliance is attached to the maxillary dentition through the bands of the maxillary molars and premolars. The anchor molar and premolar bands are connected to each other by 0.9 mm stainless steel wire that was soldered to the lingual surface of the bands. The wire from the anchor teeth was then soldered to the wire of the expansion screw. The expansion screw was also soldered to the molar band that need distalization. An acrylic button was added to the wire crossing the palatal slope above the rougae for more anchorage Results: The clinical application showed a unilateral class H molar and canine relationships were corrected by the appliance. The posttreatment panoramic radiograph showed that the roots of the teeth were fairly parallel, and the maxillary left lateral incisor was positioned into the arch. The supporting tissues appeared healthy. The posttreatment cephalometric radiograph and superimposed tracing showed no significant changes in the skeletal measurements after treatment, as expected, with no orthopedic treatment. Conclusion: The appliance was found to be effective in correcting unilateral molar Class H, and therefore it is recommended for clinical use on cases indicated for its use.