What began as a routine dental appointment turned into a heartbreaking tragedy for the family of 9-year-old Silvanna Moreno, who died on March 18, 2025, just hours after undergoing treatment at Dreamtime Dentistry in Vista, California.
According to the San Diego County Medical Examiner, Silvanna’s death was accidental. The official cause was methemoglobinemia, a rare condition that affects the blood’s ability to carry oxygen, brought on by the administration of nitrous oxide during the procedure.
Silvanna had been given children’s Tylenol the day before her three-hour appointment, during which she underwent a root canal and multiple tooth extractions, including the removal of a decayed permanent tooth. Dreamtime Dentistry said she was a new patient, referred for extensive treatment.
Dr. Ryan Watkins, the anesthesiologist overseeing her case, said Silvanna had no known health issues and was deemed suitable for outpatient general anesthesia.
Following the procedure, Silvanna was moved to recovery. Her mother reported she seemed unusually drowsy, only occasionally opening her eyes and mumbling. Once home, she continued to sleep. Roughly 30 minutes later, her breathing slowed. When her family couldn’t wake her, they called emergency services. She was transported to the hospital, where she was later pronounced dead.
“We are profoundly saddened by the tragic loss of Silvanna Moreno, and our hearts continue to go out to her family,” Dr. Watkins said in a statement.
Silvanna’s death sheds light on the rare but serious risks associated with sedation in pediatric dental care.
