前伸咬合对可复性关节盘移位患者关节振动的作用

目的:研究前伸咬合对可复性关节盘移位患者颞下颌关节振动的影响。方法:30例可复性关节盘前移位者分别作正常开闭口运动(正中颌位开始的最大开闭口运动)以及前伸开闭口运动(下颌前伸至切对切开始的最大开闭口运动),运用关节振动分析仪收集2种下颌运动方式下的关节振动信号,结合Joint-3D技术记录并分析开口度、开口型的变化,并对数据结果进行统计分析。结果:前伸开闭口组关节振动的振动总能量TI、频率小于300 Hz的振动能量A、频率大于300 Hz的振动能量B、峰振幅PA明显小于正中颌位最大开闭口运动组(P<0.01)。2种运动产生振动的峰频率PF以及频率大于300 Hz的振动能量与频率小于300 Hz的振动能量之比B/A 没有差异。2种运动方式下,开口度无明显变化,而37.4%的可复性关节盘移位患者前伸开闭口的下颌偏离中线距离比正常开闭口运动小。结论:下颌前伸至切对切可降低可复性关节盘移位患者的颞下颌关节区振动的强度但不改变其频率特性,部分患者可以改善开口型。本研究从定量化的角度为调整下颌前伸的再定位咬合板治疗可复性关节盘移位的可行性及有效性提供了佐证。

Influence of Mandibular Protrusion on Joint Vibration Recorded from Temporomandibular Joint Reducible Disc Displacement

Objective: To assess the impact of mandibular protrusion on joint vibration recorded from the temporomandibular joint (TMJ) reducible disc displacement. Methods: The vibrations of the TMJ were recorded bilaterally from 30 subjects with reducible disc displacement by joint vibration analysis (JVA) in two movement patterns (1.open/close cycle from the intercuspal position; 2. open/close cycle from edge-to-edge position). Mandibular opening and its pattens were recorded and analyzed by Joint-3D technique. Results: The values of total integral and peak amplitude (P<0.01) in movement 2 were lower than that in movement 1. The wave patterns of the power-frequency spectra for all participants were qualitatively similar unimodal spectrum in two types of movement but with lower amplitude in movement 2. There was no significant difference between 2 movement patterns for peak frequency (P=0.705) and the ratio of >300 Hz/<300 Hz (P=0.386). Conclusion: Edge-to-edge open/close movement can reduce the intensity of joint vibration compared to the open/close cycle from the intercuspal position. The electronic recording of vibrations in TMJ can provide a quantitatively analysis and reliable evidence for repositioning splint through mandibular protrusion.