After completing his orthodontic training at the University of Minnesota, Dr. Hang joined the faculty there to teach orthodontics. He later established an orthodontic practice in rural Vermont. After practicing traditional orthodontics for 7 years, he saw serious limitations in esthetics and function with the traditional approach to orthodontics.

In 1981 Dr. Hang embarked on a continuing education odyssey which has so far taken him to 50 states and over 30 foreign countries in a quest for a better way to do orthodontics. In the process he moved to Southern California and developed a truly unique orthodontic practice with strong emphasis on facial esthetics achieved with innovative early treatment and adult treatment. Approximately 15 years ago he became aware of the significant positive affect some of his treatments were having on the airway. This opened up a whole new aspect of orthodontics - maximizing the airway for ALL orthodontic patients and specifically treating patients with SDB (sleep disordered breathing) or OSA (obstructive sleep apnea).

Dr. Hang recently trademarked the term Extraction Retraction Regret Syndrome™ or E.R.R.S.™ which describes a symptom pattern common to many dental patients in virtually all dental practices. It is his treatment of E.R.R.S.™ and specifically reopening extraction spaces that has brought patients from more than 20 states and several foreign countries to his practice. He is lecturing internationally about the new era of non-retractive orthodontics which represents a 180 degree paradigm shift for the orthodontic profession.