"He took a pretty good blunt trauma to the face," said Dr. Paul Marks, Raptors medical director.
Bosh had a displaced nasal fracture repaired Wednesday in an operation performed by Dr. Frank Papay at the Cleveland Clinic. He will remain in the hospital overnight, and is scheduled to return to Canada Thursday.
The Raptors have a one-game lead over Chicago for the final spot in the Eastern Conference playoffs with five games left, including Wednesday night's game against Boston, and aren't likely to get Bosh back before the end of the regular season.
"It's not a fracture that would require screws or plates or anything like that," Marks said. "It's just a small flap of bone, per se, that's been put back in the right position so that it maintains that structural integrity. This would be in the time frame of weeks, perhaps, to set in place and to be healed."
Toronto's leading scorer sustained a "maxilla and nasal fracture to the right side of his face" when he was accidentally struck by the Cavaliers' forward in the opening minutes of Tuesday night's 113-101 loss to Cleveland.
"It's disappointing for him because he'd been playing very well and it's disappointing for us as a team," coach Jay Triano said. "We wish him all the best and hopefully he gets healthy."
Bosh was coming across the foul lane when he was hit by Jamison's flailing left arm. Bosh immediately dropped to the floor and grabbed his head in anguish as blood streamed from his face. He was taken to the Cleveland Clinic, where a CT scan revealed the fractures.
Marks said Bosh was checked by an ophthalmologist, who said there were no vision problems. The maxilla fracture was non-displaced, and did not require surgery, but the decision was made to repair the nasal fracture.
After hosting the Celtics, the Raptors play at Atlanta on Friday before hosting the Bulls on Sunday. They'll play at Detroit on Monday before ending the regular season with a home game against the New York Knicks.
"We have five games left to solidify this season and make it worth something," Raptors swingman Antoine Wright said.
The Raptors have lost 15 of 22 and are 3-4 without Bosh this season.
"When something like this happens it's time to rally, it's not time to fold the tents," Triano said.
Bosh, who is eligible for free agency after this season, is averaging 24.3 points and 11 rebounds per game, both career highs.