Nine-year-old Silvanna Moreno passed away on March 18, 2025, just hours after undergoing a dental procedure at Dreamtime Dentistry in Vista, California, turning what should have been a routine dental visit into a tragedy.
The San Diego County Medical Examiner’s Office has now declared her death to be an accident, more than two months after her untimely death.
“Methemoglobinemia in the setting of recent nitrous oxide administration” was listed as the cause of death.
According to the Cleveland Clinic, MetHb occurs when nitrous oxide affects hemoglobin, reducing oxygen transport to tissues and causing hypoxia.
AUTOPSY REPORT OUT
Authorities have revealed what caused the sudden death of 9-year-old Silvanna Moreno after a dental surgery. READ: https://t.co/53qkgYDkeu pic.twitter.com/mZjUqV01GS
— PhilSTAR L!fe (@philstarlife) May 30, 2025
Red blood cells’ ability to carry oxygen throughout the body is impacted by this rare blood disorder. Some people have blue or purple lips, skin, or nails as a symptom, while others show no symptoms at all.
People claims that the day before the three-hour procedure, Silvanna was given children’s Tylenol because she had a fever.
The girl was referred to the dentist’s office for a root canal on a molar, and they reported that she was a new patient.
Several baby teeth and one permanent decayed tooth were extracted during the dental procedure that resulted in the 9-year-old’s death.
The office’s licensed anesthesiologist, Dr. Ryan Watkins, reportedly told NBC News in a statement that “Silvanna was a healthy 9-year-old with a history of regular medical checkups.” She was “an appropriate candidate for outpatient general anesthesia,” he continued, after completing the office’s routine preoperative evaluation.
Silvanna Moreno, 9, dies after dental surgery under anesthesia at Dreamtime Dentistry on March 18. After being discharged and sleeping all the way home, she went to bed only to be found unresponsive later.https://t.co/lJLxvhGpq3 pic.twitter.com/9dLMbpF5fY
— Lipstick Alley (@lipstickalley) April 1, 2025
The girl was transferred to a “recovery room” after the procedure, according to the Medical Examiner’s summary report. Investigators were informed by Silvanna’s mother that her daughter was “out of it while intermittently opening her eyes and incomprehensibly mumbling,” the report added.
She was asleep both on the way home and when they got there. Her breathing slowed about thirty minutes later. Following their unsuccessful attempt to rouse her, they dialed 911.
After being taken to the hospital, Silvanna was declared dead.
“Our hearts continue to go out to her family during this extremely difficult time, and we are deeply saddened by the tragic loss of Silvanna Moreno,” Watkins stated.
In 2016, Watkins was investigated for the death of a 54-year-old man who nearly died while under general anaesthesia. It was determined at the time by the Dental Board of California that one of the drugs he received shouldn’t have been given to him in the first place because it caused his heart to stop.
Watkins was put on probation from 2020 to 2023, according to a decision order.
