Fine thing. 
At the beginning of my work with three.js I wanted to see the arrangement of the vertices and faces, so I did something similar, but simpler with THREE.Line.
function vertexFaceNumbersHelper( mesh, mode, size, color ) {
// mode: 0 nothing, 1 vertex, 2 face, 3 vertex & face
Memorized there:
for BufferGeometry
Addon to create special / extended geometries Magic Sphere, Magic Box
for Geometry
[SOLVED] Are segments in a side selectable? - #3 by Frustrated-Programmer
Code also on GitHub