Combined Therapy With Modified Pendulum And Fixed Appliance In The Complex Malocclusion

Objective:The purpose of this study was to modify the traditional pendulum and combinedly use it in the complex malocclusion,and to analyze if the pendulum can provide enough molar distalization and contribute to severe malocclusion correction.Methods:A total of 25 patients,who visited our department(the department of Orthodontic,the 2^nd hospital of Hebei Medical University)from July 2014 to June 2017 with complex malocclusions,were involved in this study.Each patient had an abnormal mesial moved upper first molar and their main symptoms expressed as at least one of the severe crowding,multiple impacted teeth,open bite,hypodontia and skeletal class?malocclusion.1.Modified pendulum has been made according to symptoms of patients and used with fixed appliance to correct molar relationship and others severe malocclusion.2.All the patients were asked to make study models to measure parameters such as the length of palate and overjet to evaluate the effect of molar diastalization.3.Skeletal malocclusions were taken lateral cephalometric radiographs to analyze the relation between maxillary and the mandible,and meanwhile to assess the changes of the profile.Results:1.Modified pendulum appliance can expand maxillary arch to create sufficient space for leveling and aligning misplaced teeth and efficiently improve molar relationship.A variety of severe malocclusion symptoms can be corrected,and ideal occlusal relationship can be achieved by non-extraction.2.Among the 25 patients:4 patients have completed treatment.21 patients have finished molar diastalization.2.1 The modified pendulum appliances showed diastalization of 3.67mm per molar,the average movement is?0.57±0.09?mm per month.average time of modified pendulum appliance was 6.7 months.2.2 The degree of congestion to average reduced?8.08±1.87?mm?P<0.001?.2.3 The overjet changed from a large difference?+8.21mm--5.12mm?to standard values.3.The obvious changes in sagittal position relation between maxilla and mandible has been found in skeletal Class?malocclusion?no statistical analysis?,The facial profile of some patients was improved.Conclusions:1.The modified pendulum appliance can enhance and utilize the anchorage and can be used in different treatment stages to meet the needs of different symptoms.2.Patients with maxillary molars which need to be distalized can be effectively attained,relieve crowding and serious malocclusion symptom.Reaching stable relationship between cusp fossa staggered while aligning and restoring anterior teeth to get normal overbite.3.The modified pendulum appliance combined with the application of other orthodontic appliance also greatly improved the appearance of some patients with skeletal malocclusion.4.In this study all the first molars reached the clinical requirements.For some cases of severe crowding,it is necessary to further observe the interaction between the second and the third molars and the long-term stability of therapy.