Strange geometry showing on model only in rendered view

Basically, I’ve modeled a human head and all seems well except for in one place, one of the faces did not show up in the solid, textured, or render display.

DETAILS: Modeled half the head with a mirror modifier that is filling in the other half. There is also a subsurf modifier that is smoothing everything out except for that lower lip!

I’m very new to blender, so I checked online and found that it was a normals problem, I flipped the normal and it looked good. Until I changed to render display, where the strange angular geometry can be seen.

I screencapped the whole screen in case there is valuable info that I don’t know I should tell you. Those images are attached.

Thanks in advance for any info you can provide!

it looks likes it’s set to solid shading instead of smooth on those faces. there’s a button to make it smooth over on the tool shelf on the left. but it also looks like there might be some z-fighting, indicating the presence of doubles, which can be fixed with ‘remove doubles’ also on the tool shelf. also your topology could be improved a bit. now that you have a basic head shape, you could create a new mesh over it, with optimal topology, using the retopo / surface snapping tools.
(edit) also, it looks like you have some n-gons ( faces with more than four edges ) which will lead to bad subsurfacing, and make it impossible to animate properly. it’s best to avoid those.