You deserve a beautiful smile! Fixing your teeth is an investment in yourself. It is very important to have straight teeth for esthetic reasons as well as for your overall health. Crowded teeth are difficult to clean, and can harbor bacteria that can cause decay and periodontal disease. Bacteria in your mouth can spread into the rest of your body and cause problems such as heart disease and lung infections. I'm glad that you are seeking advice on treatment. The shape of your teeth is very nice and I can envision with the proper treatment sequence that you can have an amazing smile. The problem I see, is that your upper and lower jaws are very narrow and your teeth are collapsed inward, so your teeth do not have enough room to line up next to each other. Room for your teeth can be made by different methods including jaw surgery to widen the jaws, extraction of a few teeth on upper and lower, IPR or inter proximal reduction which means carefully filing the sides of multiple teeth, or orthodontically tipping your teeth outward. Due to your severe crowding you will likely need a combination of these methods. Usually with severe crowding you will have difficulty cleaning your teeth and can develop early periodontal disease, decay and bad breath. Your first appointment should be with a general dentist to get a good cleaning and check for cavities. Looking at the pictures, I think you may have a cavity on your lower front tooth and some on your lower molars. Once your mouth is healthy, you will be ready for your staightening phase. Your treatment modality will depend out what you desire as an outcome. If you want perfectly aligned teeth no matter the cost or invasiveness, you might expect a treatment plan to consist of jaw surgery and traditional braces. If you're goal is an improved, nice smile, with no surgical down time and no sign that you are being treated, then Invisalign could offer you quite a bit of improvement, and be comfortable and invisible. I have treated some crowded cases with Invisalign with great success. Very crowded cases, like yours, may need some camouflaging restorations like with bonding or veneers to make the result look even better. Make sure you are very clear with your dentist as to what are your goals and limitations for treatment and outcome. Your treatment will likely take a few years, but you will will have the rest of your life to enjoy have an amazing smile and better health. Good Luck To You!