**Cause of Death Revealed for 9-Year-Old Following Dental Anesthesia**

Tragic Death of 9-Year-Old Silvanna Moreno After Dental Procedure in Vista, California

A 9-year-old girl from Vista, California, tragically passed away on March 18, 2025, following a dental procedure at Dreamtime Dentistry.

The San Diego County Medical Examiner’s Office confirmed that her death was caused by methemoglobinemia, a rare condition associated with excessive nitrous oxide exposure, which impairs the blood’s ability to carry oxygen.

Details of the Procedure and Aftermath

Silvanna Moreno, a third-grade student, underwent a three-hour dental surgery under general anesthesia. She was monitored throughout the procedure and showed no signs of complications. After the surgery, she was discharged in stable condition. However, during the car ride home, she fell asleep and remained unresponsive upon arrival. Despite efforts to revive her, she was pronounced dead at Rady Children’s Hospital in San Diego. 

Investigation and Medical Insights

Dr. Ryan Watkins, the dentist responsible for the procedure, stated that methemoglobinemia is an extremely rare condition and emphasized that standard protocols were followed. The condition typically presents with low oxygen saturation levels, but Silvanna maintained normal readings throughout her treatment. The dental office is conducting an internal review to understand the incident better. 

Background on Methemoglobinemia

Methemoglobinemia is a condition where hemoglobin is oxidized, reducing its ability to carry oxygen. While nitrous oxide is commonly used in dental procedures, it can cause this condition in rare cases. Symptoms may not be immediately apparent, making it challenging to diagnose during routine monitoring. 

Family’s Request for Privacy

The Moreno family has requested privacy as they grieve the loss of their daughter. They have expressed their desire for a thorough investigation into the circumstances surrounding Silvanna’s death.

Conclusion

Silvanna Moreno’s untimely death serves as a poignant reminder of the potential risks associated with anesthesia in pediatric dental procedures. It underscores the importance of vigilance and adherence to safety protocols to prevent such tragic incidents.