it is not possible to surgically straighten teeth.  One way that I create the illusion of straght teeth is to placed veneers on the front surfaces of the teeth. This does require a large amount of tooth removal and can meen the nerves of the teeth need treatment.  The ideal treatment would be to have braces ( such as Inman aligner) to move the teeth into a better position before veneering as this would mean minimal preparation of the tooth and greatly reduce the chances of root canal treatment.  Inman aligners can often move teeth into a better position within 3 months.