Front Tires

What causes a small dent or dip in the front tires. Do I need a front wheel alignment?

You mean like cupping? Where there are little 'bowls' in the tread?

Look at your control arm bushings, and also your tie rod ends.

I can also see an improper caster alignment causing this.

do I need a front wheel alignment?

Probably, but first, have the front end components checked for wear before you do so :2cents:

What causes a small dent or dip in the front tires. Do I need a front wheel alignment?

you talking about the side wall ? the belts can cause a bulge or indentation when the tire hits a hole ..

if the tread has even wear across the face of the tread alignment is correct.

any side wall bulges best take to tire shop..