The Clinical Effect Of Treating Acute Anterior Disc Displacement Without Eduction By Pivot Splint

Objective:Patients with acute anterior disc displacement without reduction were chosen and treated by pivot splint. Before and after treatment, EMG and clinical examination were taken in order to analyze the improvement of maxillofacial muscle functional status, so as to investigate the effect of pivot splint in these patients.Methods:According to the indication of acute disc displacement without reduction and X-ray, 6 cases were chosen from the patients whose chief complaints were pain in maxillofacial region, sudden limited mouth opening and the opening-type abnomality in our hospital. They were treated by pivot splint The changes of the value of visual analogue scale, joints clicking and the opening-type were observed, and the EMG activities of the maxillofacial muscle was recorded before and after the treatment, so as to discuss the clinical effect of pivot splint in these patients.Results:1.After the treatment, the patients' clinical symptoms improved. The pain in maxillofacial region reduced or disappeared, the opening-type changed, and the TMJ moved freely. 3 cases'joints clicking appeared again, while others did not.2. All the cases' value of VAS decreased significantly after the treatment.3.EMG①After being treated with pivot splint, all the cases' MPP electrical activity of bilateral TA and MM was significantly reduced (P<0.05) . The ICP electrical activity of MM at the affect side was significantly increased (P<0.05) . The ICP electrical activity of TA at the affect side and the ICP electrical activity of TA and MM at the non-affected side were not changed significantly.②After being treated with pivot splint, both masticatory muscle total asymmetry (Astot) and masseter muscle asymmetry (ASMM) decreased significantly (P<0.05) . Anterior temporalis asymmetry (ASTA) had no significant changes.4.After the treatment, the Schüller X-ray showed that 2 cases' condylar process had returned to normal position, 3 cases' anterior space was larger than posterior space, but the movement of condyla process recovered, while 1 case had no significant change.Conclusions:1. The pivot splint was effective in treating patients with acute anterior disc displacement without reduction. After the treatment, the patients' articular disc may return to normal physiological position, or they change into anterior displacement with reduction. The position of the disc and process was adjusted, the muscular function was improved and the clinical symptoms were relieved, so as to prevent the disease prolonging to chronic phase.2. After the treatment, the EMG results showed that the EMG activities of the patients' maxillofacial muscle improved partly. It needed further long-term observation.