The Maxillary Skeletal Expander is an innovative novelty TAD supported expander (MARPE, SARPE). MSE was invented by Dr. Won Moon of UCLA. His accolades from MSE in orthodontics have made a renowned impact on how we perceive the advancement of patients. MSE is considered a transverse parallel bone-bone expansion through bi-cortical engagement from the cortical bone. Success cases vary from unilateral/ bilateral crossbites, Class III to Class I, and even OSAS. Innovations in orthodontics from MSE inventor Dr. Won Moon is why this specialty appliance is one of a kind.