Based on your history and assuming that you cannot assess medical advice due to corona virus lockdown, I am giving you my opinion.
Swelling without pain and that too without history of trauma is almost always worrisome . He will have to get examined and investigated initially with an X-ray first and then a proper treatment plan can be given.
Next Steps
If swelling is persistent or is increasing since last 2 week then immediate medical advice should be sought. However if swelling is decreasing and there are no other symptoms then you can try ICE Application ( Take ice in a cloth) 2 to 3 times a day. Tab Phlogam twice a day before meals can be taken to reduce swelling. I wouldn't advice any pain killers as there is no pain