What can I do too fix the dent in my lips? (photos)

Thank you for your question. You are asking about an indentation in your lips which you noticed a few years ago, and were hoping would even out.
I can help guide you with this issue, in the absence of a physical exam. I’m Dr. Amiya Prasad. I’m a Board Certified Cosmetic Surgeon and Fellowship Trained Oculoplastic Surgeon. I’ve been in practice in Manhattan and Long Island for over 20 years. I often treat the lips and lip area for volume correction, uneven smiles using Botox, and lines and wrinkles around the mouth.
With the close up pictures you provided, I can see a slight indentation. You may be noticing this indentation when you look closely at the mirror, but I think others will not likely notice it. We tend to focus and obsess about small details of our face, but in reality other people look at our face as a whole. I don’t think others will likely notice this, even from up close, so I advise you to consider not doing any treatment at all.
If you really want treatment, you can consider a soft hyaluronic acid filler like Restylane or Restylane Silk  to even out your lip volume. It will be a small correction as there isn’t much unevenness there. Softer hyaluronic acid fillers last about 6 months before they are safely metabolized by the body, so this will require maintenance. I don’t advise semi permanent or permanent fillers as there are too many risks associated with them, and may need surgical removal as your face changes with age. Again, to avoid maintenance for a very minor issue, I would encourage you to consider not having treatment.
There is a high likelihood that your lip will even out. The lips do lose volume with age, and this can cause some evening of your upper lip. As volume diminishes with age, you can consider applying conservative amount of lip filler to achieve more fullness, but without looking overdone. It is always easier to add more with enhancement, than it is to subtract if they are overdone.If you do decide to go ahead with treatment, look for doctors who can do lip enhancement with a minimum amount of pokes into the lips. I perform lip augmentation using blunt cannulas instead of needles, which minimizes trauma and swelling after the procedure. I also minimize the entry points in the lips to avoid issues like temporary bumps and bruising. Again, I do suggest you appreciate your full lips as they are now, and not worry about unnoticeable imperfections. You will have plenty of time to enhance your lips when you are older. I hope you found this information helpful. Thank you for your question.

Lip augmentations with fillers is a great option to improve the fullness, suppleness and symmetry of the lips. Results can be very natural-looking and will feel very natural. I prefer to use a micro cannula to inject the lips to prevent bruising. Look for a cosmetic dermatologist or plastic surgeon who is an expert in fillers to discuss your desired results and concerns and go over the cost of your procedure. 
I hope this helps.

Olivia.   It appears from the photograph that the lump may be secondary to scar tissue after inadvertently biting your lip, perhaps while sleeping. Since your lips are quite full and attractive, direct excision of the lump alone is probably all you need. It can be done in the office under local and the anesthesia.  Fillers are temporary and your lips are attractive and full enough.  Costs vary from city to city, and would run between $1000-$3000 in New York City.  Be certain to consult with a board-certified plastic surgeon. Good luck !