Dispatcher reported a B767 flight crew received a gear disagree message after takeoff. After unsuccessfully attempting to manually extend the landing gear the flight crew returned to departure airport where they landed the aircraft safely and awaited tow off runway.

Narrative

Gear disagree EICAS MSG after takeoff. [Priority handling requested]/returning to ZZZ. Initially overweight landing by 15000lb. During configuration for landing no green indication. For the R main gear after extension. Manual extension attempted and was unsuccessful. It is in question whether the aircraft gear is down and locked.R side brace EICAS MSG illuminated; gear door EICAS MSG illuminated; & gear disagree MSG extinguishedA conference via SATCOM was initiated with Maintenance Control and Chief Pilot. Attempts were made by Chief Pilot to have Boeing tech join the patch; however this was not successful. G force maneuvers were recommended by Maintenance Control yet unsuccessful yielding any changes in the above EICAS messages.Switching EICAS displays as recommended by Maintenance Control unsuccessful. Recycling gear was not recommended by Maintenance Control due to the possibility of inducing further damage.Re lamping also not recommended by Maintenance Control due to potential electrical issues.Next course of action was initiating a fly-by to ZZZ Tower to confirm gear status.ZZZ Tower confirms gear down however we had no confirmation on whether it was locked.Fuel on board at this time is now 40;000 lb and the aircraft is now below max landing weight. Captain and Dispatch concurred with plan to burn down another 10000lb-12000lb (45 min) for safety margin and prep cabin for an approach into ZZZ. Partial or gear up landing procedure was briefed.There was inquiry about checklist item for R side brace MSG and selecting all fuel pumps off at pattern altitude. Maintenance Control confirms suction feed will initiate. Tug and gear pins arranged for arrival on runway to mitigate gear collapse. Aircraft landed without incident XXL. Holding position on runway for inspection and tow.During debrief Captain had mentioned a loud pop sound upon touchdown which sounded like the brace locking into place.I had been relieved of my dispatch duties at XA30 which was 11.5 hours of dispatch duty. The event occurred just prior to turnover time and I had been requested to stay on duty until safe landing of the aircraft.