Abstract: PURPOSE: To evaluate the clinical efficacy of small needle knife therapy combined with exercise therapy in the treatment of anterior disk displacement without reduction of temporomandibular joint (TMJ). Methods: Thirty-two patients with anterior disk displacement without reduction of TMJ were randomly divided into the experimental group (n=16) and the control group (n=16). Patients in both groups received health guidance, manual reduction, exercise training. Patients in the experimental group were given small needle knife treatment at the same time. Visual analogue score (VAS), maximum mouth opening (MMO), Fricton TMJ index of the two groups were compared and analyzed before treatment, 3 months and 6 months after treatment. MRI examination was performed to observe the reduction of TMJ of the two groups. The measurement data were analyzed with SPSS 19.0 software package. Results: The average MMO of the control group was 25.95 mm before treatment, increased to 38.71 mm after treatment, and the average MMO was 38.94 mm and 38.94 mm at 3 and 6 months of follow-up, respectively. The MMO of the experimental group was 26.3 mm before treatment, increased to 41.06 mm after treatment, 41.04 mm and 41.19 mm at 3 and 6 months of follow -up, respectively. VAS scores in the control group were 3.93 before treatment, 1.60 after treatment, 3 and 6 months after treatment decreased to 1.18 and 0.62, respectively; while in the control group were 4.063 before treatment, 0.80 after treatment, 3 months and 6 months after treatment decreased to 0.375 and 0.25, respectively. Fricton TMJ index significantly improved 3 months and 6 months after treatment, and the treatment effect was significantly different before, after treatment and between the two groups (P<0.05). MRI examination suggested both groups were diagnosed as anterior disc displacement without reduction before treatment. In the control group, 3 months after treatment, 6 of the 16 patients were diagnosed as reducible anterior disc displacement; 6 months after treatment, 3 patients relapsed into anterior disc displacement without reduction.In the experimental group, 3 months after treatment, 5 of the 16 patients were diagnosed as reducible anterior disc displacement; 6 months after treatment, 2 patients relapsed into anterior disc displacement without reduction.The disc-condylar relationship of TMJ in both groups was significantly improved compared with that before treatment (P>0.05). There was no significant difference in therapeutic effect between the two groups after treatment (P>0.05). Conclusions: Small needle knife combined with exercise therapy is more effective than simple exercise therapy in the treatment of irreversible anterior disc displacement of TMJ.

Key words: Small needle knife, Exercise therapy, Temporomandibular joint disc, Manual reduction, Temporomandibular joint disc displacement without reduction