The 23-year-old suffered the double fracture in the game at Harlequins earlier this month, but has made a speedy recovery and hopes to be back in action within the next two weeks.
Itoje admits the injury is the most painful he has ever experienced but will put it behind him and return stronger than before.
"All in all it's looking good, I'll be back on the pitch soon," Itoje revealed. "When I first broke it they told me potentially up to three months out, and now I am well within my timeframe of four to six weeks.
"I'm not quite there yet - and still have a couple of weeks to go."
Itoje, whose hectic schedule in 2017 included a British and Irish Lions tour of New Zealand, is stepping up his training and is feeling better for it.
"I had a week of downtime after the operation to let the jaw settle a bit, and started training last week," he said. "I'm starting to feel sharp again, and hopefully when I come back I will be a little bit stronger and a little bit quicker, and ready to go."