Clinical and MRI study of patients with conservative treatment for TMJ anterior disc displacement *
Purpose:The aim of this study was to investigate the relationship between the clinical symptoms（maximum mouth opening: MMO, visual analog scale of TMJ pain:VAS）and magnetic resonance images（disc displacement, joint effusion: JE, fibrosis of the retrodiscal tissue: FRDT）in internal derangement（ID）of the temporomandibular joint（TMJ）. Patients and Methods:We evaluated 27 joints（22 right and 5 left）in 27 patients（19 women and 8 men）with ID in this study. The average age of the patients was 40.6 years（13 to76 year old）. MRI showed that 12 joints with ID had anterior disc displacement with reduction group Ⅲa）and that 15 joints with ID had anterior disc displacement without reduction（groupⅢb）. All patients underwent conservative treatment with stabilization splints and nonsteroidal anti-inflammatory drugs. Results:After a mean time of 3.9 months, the average maximum mouth opening showed a statistically significant increase from 36.8mm to 45.6mm in group Ⅲa and had statistically significant increase from 31.6mm to 40.6mm in group Ⅲb（P＜.05）. The average VAS of TMJ pain was significantly reduced from 28.5 to 4.9 in group Ⅲa and from 39.0 to 7.1 in group Ⅲb（P＜.05）. The conservative treatment success rate for the 27 patients was 85.2％（23/27）. Among the 4 unsuccessful cases, there were 3 in group Ⅲa and 1 was in group Ⅲb. The degree of JE indicated by a high signal intensity of T2-weighted images was divided into four grades. FRDT, indicated by low signal intensity on proton density and also low signal intensity on T2-weighted images, was seen in only four cases in group Ⅲa. Conclusions:There were no correlations between MMO at first examination and the VAS of TMJ pain at first examination or between MMO at the final examination and the VAS of TMJ pain at the final examination. Neither was there any significant correlation of MMO or the VAS of TMJ pain with magnetic resonance images JE, FRDT）. (Accepted on December ３，2005)
