Temporomandibular Joint Disc Displacement, With Reduction

The goal of this clinical trial is to evaluate the long-term outcome of surgical intervention (arthroscopy or discectomy) due to the diagnoses temporomandibular joint disc displacement with or without displacement. The main questions it aims to answer are: * Does the surgical outcome recorded at the earlier 6-month follow up persist at the long-term follow up approximately 10 years postoperatively? * How does the radiologically determined degree of joint degeneration change with time in patients that have had joint surgery? Researchers will compare the six-month surgical outcome to the ten-year outcome to see if temporomandibular joint surgery results are stable over time. Participants with an earlier performed joint surgery will: * Have a clinical examination approximately ten years postoperatively. * Have a temporomandibular joint x-ray scan performed (cone-beam computed tomography).

The goal of this clinical trial is to compare the intervention arthroscopic lysis and lavage to the intervention operative arthroscopy in treating disabling and painful temporomandibular joint disc displacement with reduction. The main questions it aims to answer are: * Which surgical method that best improves mouth opening capacity, TMJ pain, and TMJ disability? * If any pre- or peri-operative variable/-s could be identified as a predictor for surgical outcome? Researchers will compare arthroscopic lysis and lavage to operative arthroscopy to see if operative arthroscopy works better to treat temporomandibular joint disc displacement. Participants will: * Have one of the two interventions under general anesthesia, not knowing which intervention. * Visit an external clinic for regular checkups at 1, 3, 6, 12, and 24 months after surgery. * Answer three different quality of life surveys at the checkups.