An orthodontist is a specialist type of dental professional, working on the alignment and positioning of teeth. They will be able to offer treatments like braces to help with the alignment of teeth, helping to improve the cosmetic appearance and also helping rectify issues such as an overbite. Becoming an orthodontist takes many years of specialist training, so if you have an orthodontist that works at your dental surgery, you are already at an advantage if you need corrective dental treatment.
For some types of treatment, you might need to have a referral from a dentist. This might be the case if a child is going to have braces on the NHS. For private treatments, you can simply book in with an orthodontist. This means you can have orthodontic treatment as an adult as well but it will be at a cost to you. There will be more aesthetically pleasing options available this way, like Invisalign.