"The number of patients in ICU remain the same," Adinun Kittiratanapaibool, Director of Bangkok's Samitivej Srinakarin Hospital told reporters, referring to the medical facility's intensive care unit.
"The meaning of those in ICU are those that need close attention," he said, and added that currently there were no life-threatening cases.
Of the 40 people on the flight still under treatment, 22 patients have spinal cord injuries and six have brain and skull injuries, he said.
The oldest patient at the hospital is 83 years old and the youngest a two-year-old child who suffered a concussion, he added.
Adinun had said 41 people were still under treatment, but later said one person had been discharged.
Ten British, nine Australian, seven Malaysian and four Philippine citizens were among the 41 people, according to a presentation made by Adinun.
He did not provide any breakdown of passengers and crew under treatment.One passenger died of a suspected heart attack and dozens were injured after Singapore Airlines flight SQ321 encountered what the airline described as sudden, extreme turbulence while flying over Myanmar.
More than 140 passengers and crew from the flight reached Singapore on Wednesday.
