How do forensic reconstructors know what noses (and lips) looked like?
May 3, 2013 12:44 PM   Subscribe

Noses come in many shapes and sizes. Skulls have no nose bones. Are forensic reconstructions of noses (and lips and ears for that matter) based on something we non-specialists are missing, or are the modelers just guessing? If not guessing, how do they do it?
posted by IndigoJones to Science & Nature (9 answers total) 6 users marked this as a favorite
Never really thought about it before, and definitely no expert here....but I have read that subtle variations in skull shape can be found between difference ethnic groups - which usually correlates to different shapes/sizes of noses, ears, eyes, lips, etc. I would further assume that markings or shaping of the skull and jaw might indicate differences in facial musculature, which impacts shape and size of mouth and lips.

So just like a sketch artist takes a few basic details about a person and fills a lot more in based on their knowledge and experience with these correlations, so might a 3D reconstruction modeler. Plus I imagine that they are trying, at least subconsciously, to create at least a somewhat attractive image using a bit of their imagination, especially if they have no other reference material.
posted by trivia genius at 1:01 PM on May 3, 2013

Did you come to this question from this front-page post? Seems like that story might help you a bit if you haven't seen it.
posted by dlugoczaj at 1:03 PM on May 3, 2013

It's possible to examine fossilized bones and see where cartilage was originally attached. In the case of a nose, that's going to vary some as a function of the size and shape of the nose, and I assume they have worked it all out long since by examining cadavers.
posted by Chocolate Pickle at 1:46 PM on May 3, 2013

Although I'm not sure if this is the method used any more, at one time they had numerical average flesh depth based on race/age/gender. Essentially they'd take the skull, add things that looked like pencil erasers to all the landmark points, sculpt clay onto the skull until all of those were covered, and then try to make it look like an average human that matched that profile. I think these days they do it with 3D modeling, but the principle's the same.

Google found me this paper on how the FBI did nose reconstructions circa a decade ago.
posted by tautological at 1:50 PM on May 3, 2013 [1 favorite]

Yes, they use numerical average flesh depth based on studies of males and females of different ancestral groups. See here.
posted by gudrun at 2:11 PM on May 3, 2013 [1 favorite]

Besides things like where the cartilage was attached, it's the shape of the bones plus yeah, a little inspired guesswork.

With noses, the opening in the skull will vary in width, plus there's a little bit of bone (can't think of the name of it, sorry) sticking down from the top of the nasal opening; combined they'll tell you how wide the person's nose is, how long, and how high the bridge. Lips are based on both how wide the mouth is, plus the person's race and gender.

And those pencil erasers tautological mentions them using for skin depth? What measurements they use are based on race an gender, of course, but also the era and the location the person lived in.

Finally, with some things they just flat-out guess: that reconstruction of a 14-year-old girl that was just unveiled at Jamestown? There's no way they can know her eye or hair color, so they just gave her the most common colors for her age, sex and era.
posted by easily confused at 4:01 PM on May 3, 2013 [1 favorite]

Response by poster: Good enough, I suppose, and thank you.

What would be interesting would be to see how different practitioners deal with the exact same skull. Could be enlightening whichever way it turned out.
posted by IndigoJones at 7:22 AM on May 4, 2013 [2 favorites]

Oh, and I forgot this yesterday: that TV show Bones, where she takes one glance and right away states the sex, race and age of a skeleton? Um, no, sorry: that's just on television.

Sex is derived from things like the brow ridges (heavier in adult males) and pelvic structures (wider in adult females); I understand for prepubesents, it's almost impossible to tell. Age can be guessed from the skull (sutures closing at known rates); ditto for vertabrae, and how the long bones in legs and arms close off 'growth caps'. All in all, because of individual-human variations, it can take a while to tell, not the TV-trope swift glance.
posted by easily confused at 7:24 AM on May 4, 2013

Response by poster: Never seen it. I guess now I don't have to.

Or maybe I do.

Do I?
posted by IndigoJones at 6:09 PM on May 4, 2013

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