I am having swollen lip and found a cyst in the gum below front teeth. i checked with the dentist and he said swollen lips is not because of the theet?

Swollen lip: your dentist or oral surgeon should be able to tell you why your lip is swollen. Follow up with them.

See an oral surgeon: Could be a mucocele, but really cannot tell over the internet.

See Oral Surgeon: Who diagnosed lesion as a cyst, you or a Dentist? May or may not be related to swollen lip. If your Dentist has not been able to establish cause of swelling or appropriate treatment, see an Oral Surgeon.