I had delayed replacing a crown for several years until I found a dentist I could trust. I finally found that with Dr. Carstensen and his staff. They did a wonderful job and the procedure was the best dental experience I have ever had (and completely painless)!
Serene, of course no diagnosis can be made from just a few photos, but in general, extractions are more common in adults with crowded arches. Kids who are growing can be influenced to grow more; adults can't. What has to be planned well is what will your smile look like and how stable will your bite be after braces - if the front teeth are 'brought back' then will they just be too straight up and down or will they slant forward a bit, which is more natural and makes your lips look right. The bite has to match how your jaws move and how your jaw joints work, so there isn't a real simple answer. Taking out your wisdom teeth won't affect much of anything - that's a different decision. Please keep interviewing orthodontists until you meet the one who will talk about how everything works together and begins with how it's going to be when you are finished.
When the adult canine teeth don't come in right, it is usually because the jaw didn't grow big enough to make room for all the teeth. At 18, you still may have a chance to help correct that and make room not only for teeth but for your tongue and breathing as well. Just getting the baby teeth out of there won't solve the problem - something prevented the natural course of things so that has to be found and fixed. The danger in waiting is kind of technical: the roots of the adult teeth take time to completely form but once they do the teeth don't really move all that much. If you wait too long, even orthodontics (braces) won't be able to move the teeth and treatment gets really complicated and expensive. The best thing for you is to see an orthodontist right away and discover why those teeth didn't erupt correctly, and investigate what treatment options you have now. This is important for many reasons for you to have a comfortable, healthy and good-looking smile for the rest of your life - maybe 90 years! Don't delay finding out about treatment choices!
You mention 'retainers' - this device is made to advance the lower jaw to open the airway for breathing disorders like snoring and sleep apnea. It's not a retainer to hold the teeth in place after orthodontic treatment. Your dentist can have her/his laboratory fabricate an all-metal retainer if that is what you are looking for - no reason to advance the lower jaw if you don't need that. I can't find anywhere on the website if FDA has cleared the Somnowell for sale in the US. The mechanism to advance the mandible is well-proven. Having a metal framework will give it the durability you seek, as long as the teeth are stable - plastic can be adjusted where metal usually cannot. Chrome cobalt is safe except for those with nickle allergies. Plastic can be kept fresh using UV sanitizers. Hope this helps!
There is a great chance you can get by with a filling on the chipped tooth. There sure are a lot of things to consider, but the key is to check with a dentist and ask about choices. Your area might have a Dental Health Center (a federally funded clinic), a dental school, a dental assisting school, or a high volume, low-cost private clinic. All of these are possibilities for getting a filling to close the gap with low cost. You can also call the local dental society - sometimes dentists get together to learn a new technique and need patients to use for teaching cases. Sounds a bit scary, but you will be treated by an expert while others watch and learn. Many people really enjoy being part of the learning cycle. Of course, you might choose to use limited funds to get a higher level of care, like a better filling or one of the very exciting new porcelain options. This investment will be higher at first but will last much longer. The best dentists often have payment plans to help your budget while being able to give you high value care. By far, the most expensive choice is to do nothing - that chip, if it is decay, will eventually destroy your tooth and you will spend way more money with fewer choices. Seek out a dentist soon and get some information so you can make the best choice for you. Best of luck to you.
E, this is a complicated question, and your dilemma about getting two opinions is a common one - so don't feel alone! Expansion works great for growing people - so if you were 7, or 9, or 12, this is what most orthodontists would do. Unfortunately, at 23, your jaw just can't grow like it did back then, so if the teeth are pushed sideways with that expander, they tend to tip sideways - not make your jaw bigger. This will create big troubles later. On the other hand, taking teeth out will not help you have that big, wide smile that a lot of people find most attractive. I can't see your whole face, so I don't know if this would be a great match for your body shape, but it is for a lot of folks. So what to do? There is yet a third alternative, that sounds very invasive but it is actually not so much. The oral surgeon, working closely with your orthodontist, goes under the skin on the roof of your mouth and separates the bone right where it used to grow. Then your jaw can be expanded and the bone fills in the gap. This sounds scary, but patients get through this just fine. With this option, you get to keep all those beautiful teeth and you can have a nice wide smile. There are a lot of details that have to be considered. I think you should keep looking until you find an orthodontist willing to discuss this option with you - they will have a surgeon that they are used to working with that can help you get the information you need to make the best choice for you.