How can a tmj disc displaced anteriourly, be repositioned and put into place? is an open surgery is needed for that or can it succeed by a tmj arthroscopy?

Orthotic appliance ?: Has your dentist attempted an orthotic bite appliance yet ? Tmj arthroscopy is being done with some success, the appliance would be less invasive and possibly worth a try first. Your dentist or oral surgeon appears to be informing well. Good luck.

Caution: There are ways to reposition an anteriorly displaced TMJ disc ranging from oral occlusal orthotics (mouth guards) to surgical correction. Any treatment undertaken is done with the goal of improving function and reducing pain (rather than to reposition the disc). Most treatments tend to be less aggressive and still can be very effective; i would caution against jumping on the surgical option.

Many causes: A TMJ disc can be displaced anteriorly by many causes, including: trauma, whiplash, wide yawning, heredity, missing teeth combined with an imbalanced occlusion, not wearing retainers after braces, grinding of teeth at night, clenching during the day... The disc can be repositioned (recaptured) but it will also be prone to occurring again. Surgery should be considered the last option.

Conservative Rx 1st: If you can get the disc in place (recapture) and keep it there with an orthotic, then treat it to this stable position. If you need surgery you are only treating the damage that has occurred, not why the damage occurred. Surgery must be followed with finding the best functional joint position and then maintaining that relationship with restoring the bite to that position.

Usually open surgery: Some can suture the disk with the scope. Most with open surgery. Arthroscopy can be quite successful without suturing the disk.