Aim: to compare dento-alveolar effects resulting from use of two molar distalization appliance,Pendulum and Fast-Back in treatment of class II malocclusion.
Materials and Methods: 20 patients for each appliance was studied,12 at the end of distalizationand and 8 from the start to the end of comprhensive treatment.The medium of the patients was 12,4 for Pendulum and 14,9 for Fast-Back.The subjects were compared analysing model and lateral cephalograms at 3 observation time.Results were compared each other to assess if the two appliances are able to obtain molar distalization in class II and which are the differences in dentoalveolar effects.
Results and Discussion: the time for obtaining molar distalization was on average 8 months for Pendulum and 9 for Fast-Back,the period of treatment with fixed appliance was on average 19 months with the first and 20 for the second.During molar distalization the pendulum showed more distal molar movement and less anchorage loss than the Fast-Back.Pendulum and Fast-Back were equal to obtain distal molar movement and overcorrection of molar relationship at the end of distalization but the second more bodily.At the end of comprehensive treatment the maxillary first molars were on average mesial to their original position in the Fast-Back and little distal for the Pendulum,compared to stable basicranial reference.Both appliance were equally effective in obtaining class I relationship.
Conclusion: the results,in relation to different dento-alveolar effects found,can give a hypothesis for using Pendulum or Fast-Back with specific indications for the treatment of class II malocclusion compared to dento-alveoalr and skeletal pattern or aesthetic caratheristics of orthodontic patients.