Therapeutic effect of TENS on post-IMF trismus and pain

The study set out to investigate the therapeutic effect of Transcutaneous Electrical Nerve Stimulation (TENS) in the alleviation of pain and post-IMF trismus, in patients undergoing jaw exercises to hasten mouth opening after being treated for fractures of the mandible. Two groups of patients, with 10 patients in each group, were used for the study. The groups were the experimental and the control groups. They were all treated for mandibular fractures, and had their jaws immobilized for 6 weeks, immediately after which they were started on jaw exercises. The Inter-incisal distances and number of acceptable wooden spatulae that the jaws could accommodate were noted and recorded. The experimental group was then placed on the TENS therapy for 20 minutes, after which the new inter-incisal distances and the number of acceptable wooden spatulae were recorded. The control group had no TENS therapy; the patients only waited for 20 minutes without any stimulation, before the new inter-incisal distances and the number of acceptable wooden spatulae were measured and recorded. It was observed that the inter-incisal distance and the number of acceptable wooden spatulae significantly increased in patients in the experimental group compared to the control group. It was concluded that TENS could be useful in relieving the pain associated with forced mouth-opening exercises aimed at overcoming trismus caused by muscle spasm, which is associated with prolonged immobilization of the jaws for the treatment of facial fractures.