My sheltie girl had retained all four of the baby canines and the adult ones all out at 5,5 months. Plus the lower canines were growing very narrow and straight up at the gums.
She had an operation because they said otherwise she will need to have her adult canines pulled out or cut in half so they don't grow in the gums. She had lots of stitches but she recovered well. Only problem is that she absolutely hates the tables and vets now. We went at a dog show later on and she freaked out when the man judge came to the table. At the show as a 5 months old puppy she was so cool and licked the judge. He said it was rare to meet such a sweet and open sheltie. Her fear after the operation is my only regret because in the other scenario she would have needed many more scary operations..