Some four months after the tragic death of a Harlingen boy who stopped breathing during a dental procedure, the autopsy has been released. 

The death of 10-year-old Marcos Tirado has been ruled an accident caused by a pre-existing medical condition.

Tirado suffered from Treacher-Collins Syndrome, a hereditary medical condition which causes deformities to the face and complicates common medical and dental procedures.

An autopsy obtained by Action 4 News shows that Tirado suffered cardiorespiratory arrest during a dental procedure.

Tirado was at the Harlingen Family Dentistry Children’s Dental Clinic for dental work back in September.

The autopsy shows he was administered nitrous oxide with his father by his side.

Reportedly, on two or three occasions, Tirado appeared to hold his breath, but was otherwise normal.

When the procedure was done, Tirado was not breathing.

Paramedics were called in and the child was rushed to the hospital where he died two days later.

The Cameron County forensic pathologist released the findings today. 

Tirado was a student at Lamar Elementary in Harlingen.

TIMELINE

Dental Visit on Monday, September 3rd, 2012:

2:40 pm                 Administered nitrous oxide and oxygen
2:45 pm                 Treatment initiated
3:07 pm                 911 Call Made & Resuscitation efforts begin
3:11 pm                 EMS arrives to find him unresponsive
3:28 pm                 Transported to V alley Baptist Medical Center
4:08 pm                 Cardiac rhythm restored

Pronounced dead on Wednesday, September 5th, 2012.

SOURCE: Cameron County Forensic Pathologist Autopsy