Dear Ms. XXXX, [he spelled my last name wrong too, stupid asshole]
I'm so sorry to hear about Asa's mother, and your sister, and your mother's daughter. I'm sure that this is very difficult time for all of you. You are all in my prayers.
I apoligize if his dental appointment increased your stress at this time. In the future, please let us know in advance if Asa or Valentina are going through difficult times in their life before we bring them back. It helps us give them extra care. We can certainly make sure that Asa and Valentina see our more experienced assistants for their next cleanings. We have made notes in their record to that effect.
Again we wish you the best in the difficult season in your life.