Abstract: Objective To study the clinical therapeutic effects of plane plate on Class Ⅱ division 2 malocclusion patients with temporomandibular disorders (TMD).Methods 20 outpatients who had Class Ⅱ division 2 malocclusion with temporomandibular joint disorders from January 2013 to December 2014 at Jiangsu Provincial Stomatological Hospital of Orthodontics and TMJ Branch were selected in this study.All were treated by the plane plates and used United States Myotronics K7 (Neuromuscular Dentistry analysis system) was used to record their changes of condylar trajectory and vibration frequency before and after using the flat-screen guide appliance.Results ①After being treated by plane plate,maximum mouth opening,protrusion and lateral movement all had little changes compared with the previous treatment (P> 0.05).②The style of mouth opening was changed after treatment (P<0.05).③Joint vibrations were statistically changed compared with those before treatment (P<0.05).Conclusions The plane plant can lead to open bite on deep overbite patients,improve jaw movement patterns,and relieve related symptoms of temporomandibular diseases,thus providing guidance for clinical treatment.

Key words: Angle classⅡ2, temporomandibular joint disorder, mandibular movement, joint vibration