Objectives: TMJ pain and limited mouth opening are main symptoms caused by TMJ disk displacement without reduction (DDw/oR). It is important that these conditions are effectively managed to relieve the symptoms in a shorter period as compared to its natural remission. We developed a mouth-opening exercise (MOE)-based treatment algorithm for TMJ pain and trismus caused by DDw/oR. This algorithm consists of four phases. The first phase involves MOE and nonsteroidal anti-inflammatory drugs (NSAIDs) when pain is intolerable for 1 week. When symptoms persist, the treatment progresses to the second phase which involves MOE and continuous use of NSAIDs for 2 weeks. The third phase involves arthrocentesis followed by MOE and continuous use of NSAIDs for an additional 2 weeks, followed by use of NSAIDs as needed up to 3 months. The fourth phase involves arthroscopic surgery. It is followed by MOE with NSAIDs when the maximal mouth opening is still <35 mm after the third phase. In patients with TMJ pain, MOE under NSAIDs are applied. The total treatment duration is limited to <1 year.

Methods: Eighty patients with DDw/oR were registered in this tretment algorithm and followed up for 1 year. The inclusion criteria are both VAS pain score of >34 (range, 0–100) and maximal mouth opening of <35 mm. When there is no improvement in both inclusion criteria, treatment is elevated to the next phase.

Results: Seventy of 80 patients with DDw/oR underwent the treatment algorithm described. The improvement rates of the first, second, third, and fourth phases were 29%, 61%, 41%, and 100%, respectively. Ten of 80 registered patients were dropped out from this study and classified as unimproved cases. The total improvement rate for 1 year was 88%.

Conclusions: This treatment algorithm is recommended because of its high improvement rate.