Buccal fat removal incision turned into a hole - 10 days post-op. (Photos)

Buccal fat removal requires making an incision inside the mouth close to the upper back teeth. Most surgeons close the incisions with dissolvable incisions. Other surgeons don't place sutures therefore leaving the "hole" (incision) open to heal by itself.
Some times the dissolvable stitches come out spontaneously or accidentally before the incision ( "hole" ) is healed. In my practice if a patient's buccal fat incision opens up, the incision is allowed to be healed by itself. However, my patient has to come for a follow up to double check the incision is not infected. 

It does not look like an infection at this time, just delayed healing.  That being said, you have to take utmost care to ensure this area stays clean and heals properly over the following days. Salt water rinses before and after every meal, etc.  This will help speed up the healing process.  It should close up within a week, however, keep your operating surgeon aware of what changes you are seeing.  

Looking at the pictures you have provided it's doesn't appear to be an infection. It maybe just a little delayed healing. I would suggest doing salt water mouth rinses and peridex mouth rinses to speed up the healing process.  If you are not completely healed within another week or two discuss with your surgeon