Q:

To what degree can a person's age be accurately determined from images alone?

This question has generated a good bit of discussion and controversy recently, mostly centered around the original context in which it was placed. After some rather extended discussion in chat, it seems the OP has agreed to a proper overhaul of the question so that it can achieve its original goals, remain on-topic, and stay reasonably inoffensive to a global audience.
Unfortunately, a proper overhaul would render the existing answer fairly irrelevant. So, how should we proceed with regards to the question?

Unlock and overhaul the question in-place. The existing answer would also have to be overhauld by the answerer, or it may even be better off deleted.
Create a new question, based on the proposed overhaul. This way the old Q&A are retained for historical reference, while the re-written question may get a proper answer and provide value to the community.
Don't bother changing anything. Q&A remain locked and unmodified, and we all just move on.

For reference, here's a rough first draft of the new answer based on what was discussed in chat. (Chat discussion ends around here.)

To what degree can a person's age be accurately determined from images alone?
Let's say you have pictures, or a video, of a person. This media includes views of the person's naked body from practically every angle, from a range of about 3-6 feet. This may include some shots of the person's open mouth and/or exposed genital regions.
Assume that the video and/or pictures are the only information you have. Nothing is known of the subject's medical history or family medical history, and neither the subject nor the family are available for interview, direct physical examination, or testing.
Given that subjects' ages may range from 0 to around 32 years, how accurately can their age be determined from these images alone? Is it possible to achieve accuracy to within one year or less for any or all of these possible ages? What sort of factors would one use to perform such a determination?

A:

I know that you have put a lot of effort into this question and have tried to help, but I think that the answer is that even the edit you are proposing will result in opinion-based-answers. 
I did the following Google scholar search for Human Age Determination and most everything comes up that you would have to physically exam the person. Either look at dental roots, or growth plates, or possibly through blood tests. 
None of those would be possible without access to the subject, and at that point, if there was access to the subject, then the video would only be able to represent the age of the person if something like the metadata accurately showed when it was made.
So maybe we can tell a 2 year old from a 4 year old, and we can definitely tell a 2 year old from a ten year old, but we might have a difficulty determining a 16 year old from a 17 year old, or even a 15 year old from an 18 year old. See where I am going with this... At certain stages of life, especially when there is a great degree of change, such as through puberty, not everybody ages in exactly the same way. I remember some boys with full, thick beards at 14 and some who didn't even show the beginning signs of a beard at graduation.

