Dentistry is a field of medicine that focuses on the diagnosis, prevention, and treatment of diseases and conditions of the oral cavity. Ortho, which has five letters, is short for orthodontics, which is a branch of dentistry that specializes in the diagnosis, prevention, and treatment of malocclusions, or misalignments of the teeth and jaws. Orals, also with five letters, is short for oral surgery, which is a branch of dentistry that focuses on the surgical treatment of diseases, injuries, and defects of the mouth, jaw, and face. Lastly, periodontal, with eleven letters, is a branch of dentistry that focuses on the prevention, diagnosis, and treatment of diseases of the gums and other structures that support the teeth.