Proximal portion of the matrix forms the superior aspect of the nail plate, and the distal matrix contributes to the inferior portion of the plate… 
  
Pits: 
| • | evidence of pinpoint damage to the matrix |  
 | • | represent loci where tiny clusters of parakeratotic cells have been shed from the surface of the nail plate |  
   
White spots (leukonychia): 
| • | result from damage to the distal matrix  (vs. pits) |  
 | • | represent parakeratotic cells in the deeper portion of the nail plate |  
   
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