The Effects Of Pendulum Appliance On The Anchor Teeth And The Outcome At The Completion Of The Orthodontic Treatment

Objective: The purpose of this study was to determine the effects of the pendulum appliance on distal movement of maxillary molars and reciprocal effects on premolars and maxillary incisors before and after orthodontic treatment.Methods: The study was carried out on 12 patients. The pendulum appliance applying 200 to 250 g of force to the molars, followed by fixed orthodontic appliance therapy, mean age for the study group was 13.52±1.54 years. Dentally all the patients had Angle II molar relationship on both sides. The patients were in permanent dentition, second molars were erupted, and lateral cephalograms were taken andanalyzed before and after the total treatment.Results: The cephalometric results of longitudinal assessment (initial to completion of orthodontic treatment) of 12 patients showed the following. Maxillary first molars were positioned distally by an average of 1.1 ± 1.4 mm, tipped distally 1.1 ±2.2° , and intruded 0.4± 0.9 mm. The maxillary second molars were also positioned distally an average of 0.3 ± 0.9 mm, tipped distally 1.3 ± 1.4° , and intruded an average of 0.3 ± 0.8 mm after the total treatment. The mean reciprocal mesial movement of the first premolars was 0.3 ± 1.0mm, with a mesial tipping of 0.3 ± 1.5° and extrusion of 0.2 ± 0.6 mm. The maxillary incisors to SN angle increased by 2.2 ± 2.3 , and extruded 0.8 ± 1.0mm. There was a minimal effect on the palatal plane, occlusal planes, both of them slightly decreased, while the Frankfort mandibular plane angle (FMA) and The lower anterior face height increased by 1.0 ± 1.3 mm and 2.4 ±1.8 mm respectively. In terms of facial esthetics, the upper lip to Ricketts E-plane decreased by 1.4 ± 2.2mmand the lower lip to E-plane decreased by 0.9 ± 2.2 mm. The study showed insignifisant change in the craniofacial skeletal base.Conclusions: The pendulum appliance is an effective and reliable method for distalizing maxillary molars. Its major advantages are minimal dependence on patient compliance, ease of fabrication, adjustment of the springs if necessary to correct minor transverse and vertical molar positions and patient acceptance. This study shows the pendulum appliance still having minimal effects on the anchor teeth, minimal increase in mandibular plane angle and lower anterior face height even after the comprehensive treatment and correction of class Ⅱ malocclusion.