Fig.8 (upper occlusal mirror view): A diastema is found between the upper right 1st molar and the 2nd bicuspid (<).  It appears to be caused by the distal shifting of the former, which in turn is due to traumatic occlusion.  The diastema is confirmed in a bitewing and in model.

If the nature can cause the distal shifting because of missing 2nd molar, a proper anchorage should be able to distalize the 1st molar more efficiently, e.g., a mini-implant.  Where to place it?  How much should the distalization occur?  Model surgery is necessary.

Crowding

Xin Wei, DDS, PhD, MS 1st edition 02/22/2015, last revision 02/22/2015