This script will help you to clean polygonal meshes from the useless vertex, for example after the Boolean operations. Script will find vertexes with 2 egdes only and, depending from angle between edges (treshhold you can control), will clean it. So you can leave a corner vertexes and clean vertexes on straight lines.
1) Download script
2) Run it via menu "MaxScript - Run Script" or DragAndDrop it on 3dsmax viewport
3) Choose "Customize - Customize user interface" and add script to Keyboard shotcut or in Menus, Toolbars or, like on image, in to the quad. You will find it in Category: Shiva Tools.