tight teeth frenulum remedies?

My boy’s bottom lip frenulum is tight. He’s been complaining about it hurting and it bleeds sometimes, and it’s made a gap between his teeth. He’s 6. He doesn’t seem to have problems with the upper one, but his tongue frenulum was also too tight when he was born. He had a hard time nursing, and they did a quick little…slice?...at it when he was just a day or two old. That one has been fine, but the one by his lower teeth has problems. Tonight he asked me to look online for things we can do to help.

Is there anything we can do that will help it stretch? I’m looking on google and just see frenectomy surgeries. They didn’t have to remove his tongue one, so why would they need such a big surgery for this one?