Basically, a dentist and an orthodontist are not the same. Most people interchange them, orthodontists are a specialist of dental problems.
What is their difference?
A dentist is a physician whose area of focus involves the mouth, jaw, teeth, gums, and nerves. An orthodontist specializes the teeth, they diagnose and repair overcrowded mouths, misaligned teeth and jaws, occlusions, and overbites.
The orthodontist should complete first a regular dental training of about four years, after that, they should take another two to three years of specialized training.
What does orthodontist do?
Orthodontist underwent a special training to repair misaligned teeth, they identify the issues with your mouth and teeth. Diastema is a gap between your teeth, it should be corrected for the structure of the mouth needs a tight alignment between the mouth and gums. Thus, to correct the issue the teeth should be pulled together.
The most famous teeth alignment tool orthodontist use is the braces, it has bands and brackets that are connected through a wire to pull the teeth into an upright alignment. Some use an aligner, it does not use a metal wire or bracket, and others use a palate expander.