Rough Dentogram ( clustering based on segment distance )

    L 70  78  
   !  
   8-- L 60  69  
   !     
   !      E 58  59  
   !     !  
   !     6-- E 12  13  
   !     !     
   !     5----- L 52  57  
   !     !        
   !     !         L 42  51  
   !     !        !  
   !     1--------4-- L 14  22  
   !     !              
   7-----2-------------- L 23  32  
   !                       
   3----------------------- L 33  41  
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