Routine Dental Visit Ends in Tragedy for 9-Year-Old California Girl

What began as a standard dental procedure turned tragic when 9-year-old Silvanna Moreno died hours after treatment at Dreamtime Dentistry in Vista, California, on March 18, 2025. The San Diego County Medical Examiner ruled her death an accident caused by methemoglobinemia, a rare condition triggered by nitrous oxide, which interferes with oxygen delivery in the blood.

Silvanna, who had a fever the day before the visit, underwent a root canal, multiple tooth extractions, and received general anesthesia. Following the procedure, she appeared unresponsive and lethargic. Her condition worsened at home, and she was later pronounced dead at the hospital.

Dr. Ryan Watkins, the anesthesiologist, expressed deep sorrow. Watkins has a past disciplinary record: he was on probation from 2020 to 2023 after a prior anesthesia-related incident in 2016.

The case has raised public concerns about pediatric dental anesthesia safety and oversight in outpatient clinics.