According to Atwood residual ridge classification order V denotes:
High-Yield Explanation
Order I – Pre-extraction-alveolus bearing tooth
Order II – Post-extraction-alveolus after extraction
Order III – High, well rounded-high alveolar process
Order IV – Knife-edge-High, narrow alveolar process
Order V – Low, well-rounded-rounded flat alveolar process
Order VI – Depressed-concave flat alveolar process.