Abstract: Introduction: There has been increase in number of TMD cases which may go undiagnosed and progress in severe form. There are various options for treating TMD one of them is ALF appliance .It delivers light and continuous forces when fitted in arches. This appliance mainly uses functional force for its working. ALF can improve position and function of tongue, airway dimensions, sleep due to clear airway, it facilitates breathing through nose and sinus drainage improving overall balance of facial bone. The use of ALF appliance has also been suggested in deprogramming the TMJ and help preventing aggregation of TMD symptoms in patients taking orthodontic treatment. But no such studies has been carried out to see its effect on TMD. Hence, a study is planned evaluating TMD’s in moderate group described by Helkimo index and comparing the symptoms pre and postoperatively with ALF appliance. Materials and method: Patients seeking orthodontic treatment will be checked for any TMD’s. Helkimo’s index will be recorded. Mild to moderate cases as per Helkimo’s index will be selected cases for study. Appliance is fabricated using flexible and resilient 0.025 elgiloy wire. Helkimo index will be obtained at different intervals for evaluating any changes in TMD symptoms. Conclusion: No such studies has been carried out to see its effect on TMD. Hence, a study is planned evaluating TMD’s in moderate group described by Helkimo index and comparing the symptoms pre and postoperatively with ALF appliance.