9-year-old girl dies after dental procedure in California, autopsy confirms cause
Medical examiner rules death of Silvanna Moreno accidental, linked to rare reaction from anesthesia gas
What began as a routine dental visit ended in tragedy when 9-year-old Silvanna Moreno died just hours after undergoing treatment at Dreamtime Dentistry in Vista, California. More than two months later, the San Diego County Medical Examiner has confirmed her death was accidental, caused by a rare blood condition triggered by anesthesia.
According to the official autopsy report, Silvanna died from methemoglobinemia following exposure to nitrous oxide during the procedure. The condition reduces the ability of red blood cells to carry oxygen, leading to dangerously low oxygen levels in the body.
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
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The Cleveland Clinic explains that symptoms can vary widely—from blue or purple skin, lips, or nails, to no visible signs at all—making it difficult to detect in some cases.
Silvanna had undergone a three-hour procedure on March 18, which included a root canal, extractions of several baby teeth, and the removal of one decayed permanent tooth. Her family said she had been given children’s Tylenol the day before to treat a fever.
What happened after the dental visit?
Dreamtime Dentistry’s anesthesiologist, Dr. Ryan Watkins, stated that Silvanna had been considered healthy and “an appropriate candidate for outpatient general anesthesia.” She was moved to a recovery room after surgery, where her mother recalled that she appeared groggy, occasionally opening her eyes and mumbling.
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
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On the drive home, she remained asleep and continued sleeping once home. Roughly 30 minutes later, her breathing slowed, and her family was unable to wake her. Emergency services were called, but she was pronounced dead at the hospital.
This is not the first time Dr. Watkins has faced investigation. In 2016, he was linked to another case in which a 54-year-old patient nearly died under anesthesia. Regulators later determined one of the drugs administered should not have been used, and Watkins was placed on probation from 2020 to 2023.
Following Silvanna’s death, he released a statement saying, “We are profoundly saddened by the loss of Silvanna Moreno, and our hearts continue to go out to her family during this incredibly difficult time.”
Silvanna’s death has raised questions for many families about the safety of dental anesthesia for children. A GoFundMe was launched to support her family in the days after her passing.
Her case now serves as a sobering reminder of the risks—however rare—associated with anesthesia during dental and medical procedures.
