Welcome to HCM
I would like to ask you whether you have any pus discharge from that swelling??
That bump shows there is abscess
formation in that teeth.It can be due to infection in last tooth or may be due to impacted wisdom tooth
.For getting proper treatment you need to get it properly ruled out by getting an IOPAR done of that region.
Meanwhile you can start with Zerodol-SP thrice a day along with Novaclox-LB twice a day for three days.
Also do warm saline rinses twice a day.