Although crowded teeth have been treated for over 100 years, nearly all treatment has been empirical rather than based on science and the teeth have tended to re-crowd afterwards even if some have been extracted to make room. Unfortunately there is little research showing that Orthodontic treatment is of significant long-term benefit for the patient.
On the other hand there is extensive research to show Orthotropic treatment has provided stable correction of irregular teeth and unattractive faces. This includes a comparison of Identical twins treated by either Orthodontics or Orthotropics, a comparison of children with severe overjets treated by the two methods and another comparing excellent results obtained by Orthodontics and Orthotropics. In this last case both the public and dentists thought the Orthotropic results were highly significantly better.