My daughter, 9, died after a routine trip to the dentist triggered deadly blood condition

By Admin

17 Jun, 2025

What began as a standard dental procedure ended in unimaginable heartbreak for a San Diego family. Silvanna Moreno, a vibrant nine-year-old girl, tragically lost her life following a routine visit to the dentist after what was later determined to be a fatal case of methemoglobinemia, a rare blood condition often triggered by exposure to nitrous oxide, commonly known as laughing gas.

Silvanna was undergoing a root canal, several fillings, and other dental work at Dreamtime Dentistry in Vista, California, when the incident occurred. The procedure appeared to go smoothly, with no immediate complications reported. After the procedure, she was wheeled to the recovery room and later escorted to her mother’s car.

However, what seemed like post-anesthetic drowsiness on the ride home quickly took a darker turn. Her mother described her as “out of it” and snoring loudly. When the snoring began to fade, her mother rushed to call 911. Silvanna was taken to the hospital in critical condition after her heart stopped. Despite doctors’ best efforts, she could not be revived.

A report from the San Diego Medical Examiner’s Office later revealed the cause of death: methemoglobinemia a condition in which hemoglobin, the protein in red blood cells responsible for transporting oxygen, is unable to carry it efficiently due to chemical alterations. In Silvanna’s case, the condition was likely triggered by the nitrous oxide used during her dental treatment.

According to a 2024 Toxicology Reports study, nitrous oxide is the second most common cause of methemoglobinemia when used as medical therapy, especially in children. Though rare, this condition can escalate quickly, and blood methemoglobin levels above 70 percent can be fatal. Silvanna’s levels were recorded at 75 percent during the autopsy, although these may have increased post-mortem.

Warning signs include bluish lips, labored breathing, and extreme fatigue but tragically, Silvanna reportedly exhibited none of these before leaving the clinic. Her dentist, Dr. Ryan Watkins, who has 20 years of experience, said in a statement that her oxygen levels remained normal throughout and her medical history presented no red flags.

Dreamtime Dentistry has previously been involved in another serious incident in 2016, when a patient went into cardiac arrest under anesthetic. The dentist was placed on probation in 2020 but continued to practice under increased supervision.

The day before her procedure, Silvanna had a mild fever, which had been treated with Tylenol. On the morning of her dental work, she also complained of a headache, though she appeared otherwise well. The dental team later stated that had they been informed of these symptoms, the procedure would have been postponed.

Dr. Watkins expressed sorrow over the event:

"We are committed to learning from this tragic event and will implement any additional safety measures that may help prevent such occurrences in the future. We extend our deepest condolences to Silvanna's family and ask for continued respect for their privacy during this time of grief."

This devastating story serves as a grim reminder that even the most routine procedures can carry risks. Silvanna’s death is not only a personal tragedy for her family but also a cautionary tale for healthcare providers and parents alike to remain vigilant even when everything seems routine.