[The effect of the local anesthesia to the posterior ramus of the mandible in patients with temporomandibular joint problems].

Some clinicians in North America use anesthetic injections to differentiate the symptoms such as pain and stiffness in the facial area and neck in patients with TMJ problems. However, the effects and area which is influenced have not been studied. The purpose of this study was to study procedures and changes following administration of local anesthesia to the posterior ramus of the mandible. Twenty four patients with TMJ problems were used in this study. 0.5ml of 2% Lidocaine (epirenamine included) was injected into the most painful site upon palpation. The pain upon palpation test (following Krogh-Poulsen's method) was compared before and after 50 minutes. Results of this experiment were: 1) decrease of pain upon palpation was found not only in the site. In many cases subjective pain in the head and neck area was also reduced. 2) A significant reduction was found in the pain upon palpation test in the neck area. A highly significant reduction was seen in the Sterunoclydmastoid muscle only in the injected side. In the masticatory muscles. Also, reduction of pain upon palpation was seen in both lateral, medial pterygoid and digastric muscles in the injected side. 3) Contra side lateral pterygoid muscle and trapezius muscle also registered decreased pain upon palpation. 4) The mean values for the injected site were 5.7mm (S.D. 5.9) below the earlobe and the mean depth from the skin surface to the bony surface were 16.6 mm (S.D. 2.7mm). 5) The peak of the subjective effect were seen in one group in 20 minute later injection (early type) and in the 2nd group the peak were seen after 40 minutes (slowly type). 6) We did not experienced any paralysis of the facial nerve in this study.