A sore is natural after any sort of viral infection however a detailed history is needed.

Maybe?? Go for xray to determine the cause of pain

If your brother had been hospitalised and given steroids, this might be a post covid symptom. Given the current aoccurances of mucormycosis, it is advisable to get it properly checked by nearby dentist. Besides that, he can start using an antiseptic mouthwash or salt water rinse.

Attach picture. There is possibility.

Hi, yes it’s a common oral manifestation seen in people with covid..just maintain your routine oral hygiene. Brush twice a day with a fluoridated toothpaste. Salt and Warm water gargles everyday. Eat vitamin c rich foods like lemon, potato, tomato, kiwi, orange etc and take a good care of your health. Eat well. Stay healthy and safe

Hello yeah may be cause after covid patients are very weak immunocompromised, due to which they r not able to maintain oral hygiene. Maintaining oral as well as PERSONAL hygiene is important .I will request you to consult a dentist online .