1. Causes
   1. Mesiodens
   1. High frenal attachment 
   2. Tooth are procline
   3. Tooth material arch length discrepancy 
   4. Midline pathology 

1. How to correct midline diastema?
   1. Composite restoration
   2. Finger springs = draw
   3. Fixed appliance = keychain 
   4. Permanent retention