PORTLAND (AP) — An autopsy on a senior at a Portland high school who died days after having routine oral surgery did not reveal the cause of his death, and additional tests are needed.

The unexpected death of 18-year-old Benjamin LaMontagne of Long Island last week shook Cheverus High School.

The state medical examiner’s examined the body on Monday, but a spokesman for the attorney general’s office says further tests are needed to determine why the teenager died. It could be week before those results are back.

Authorities have told the Portland Press Herald (http://bit.ly/1ft2tgn) there does not appear to be anything suspicious about the death.

LaMontagne’s parents have said they believe their son died of complications from oral surgery he had Feb. 19 for impacted wisdom teeth.