Hello and thankyou for approaching DoctorSpring with your query.
I have gone thorough you case, and understand your concern.
When you say the suture came out prematurely, what do you mean? was it soon after he put the suture? few hours later or few days later?

Ideally sutures can be put on a clean wound upto 18 hours of the trauma and within 24 hours if it is on the face if there are no chances of infection and if the patient is healthy.
Sutures are not put if it has crossed that time limit as there are chances of infection. If there are chances that the wound would be infected, if it is a non cosmetic wound, or if it has crossed this time limit it is better to let the wound heal by leaving it open and doing dressings.
One has to be careful as once the wound is sutured and if infection occurs,it has to be reopened again.

In your case now it is too late to put a suture. You need to take care to keep the wound clean.
Continue putting the antibiotic cream. If it has already been a several days, apply the cream and leave it open when you are at home as it will heal faster.
If you are going out or when there is a chance of the wound coming in contact with dirt or dust cover it with a sterile bandage.

I hope this has helped.
Feel free to follow up with any queries.
Thankyou