The Beginning of Facial Reconstruction
You have started a process to reconstruct a skull. The first step is to look at the previous page and try to determine as much as possible regarding the skull; their approximate age, their sex at birth and hopefully a ballpark of their ancestry information. Once you have a good idea of those variables, it's time to figure out how to surface the face so that it will look like the human that owned it.
Tissue Depth Markers
When a forensic artist needs to accurately reconstruct the soft tissue of a skull, it is important to follow some guidelines, otherwise the skull will look really scary, and nothing like a person. Over 19500 skulls were studied and measured to come up with these tissue depth averages.
The easiest way for a forensic artist to reconstruct a skull is to 3D print a scanned copy of that skull (like we are doing!) and glue tissue depth markers directly onto the skull. These depth markers can be made of wood or plastic. They guide the thickness and placement of facial features like skin and muscle, taking into consideration a particular age, sex, and ancestry.
Nowadays, you can also use 3D computer software to create your reconstructions without the mess!
Here's a front and profile view of the marker landmarks:
The easiest way for a forensic artist to reconstruct a skull is to 3D print a scanned copy of that skull (like we are doing!) and glue tissue depth markers directly onto the skull. These depth markers can be made of wood or plastic. They guide the thickness and placement of facial features like skin and muscle, taking into consideration a particular age, sex, and ancestry.
Nowadays, you can also use 3D computer software to create your reconstructions without the mess!
Here's a front and profile view of the marker landmarks:
Midline (only one needed)
1. Supraglabella - 4.25
2. Glabella - 5.25
3. Nasion - 6.50
4. End of nasal bones - 3.00
5. Mid-Philtrum - 10.00
6. Upper lip margin - 9.75
7. Lower lip margin - 11.00
8. Chin/lip fold - 10.75
9. Mental eminence - 11.25
10. Beneath chin - 7.25
2. Glabella - 5.25
3. Nasion - 6.50
4. End of nasal bones - 3.00
5. Mid-Philtrum - 10.00
6. Upper lip margin - 9.75
7. Lower lip margin - 11.00
8. Chin/lip fold - 10.75
9. Mental eminence - 11.25
10. Beneath chin - 7.25
Bilateral (two needed)
11. Frontal Eminence: 4.25
12. Supraorbital: 8.25
13. Suborbital: 5.75
14. Inferior malar: 13.25
15. Lateral Orbit: 10.00
16. Zygomatic arch, halfway: 7.25
17. Supraglenoid: 8.25
18. Gonion: 11.50
19. Supra 2nd molar: 19.50
20. Occlusal line: 18.25
21. Sub 2nd molar: 16.00
12. Supraorbital: 8.25
13. Suborbital: 5.75
14. Inferior malar: 13.25
15. Lateral Orbit: 10.00
16. Zygomatic arch, halfway: 7.25
17. Supraglenoid: 8.25
18. Gonion: 11.50
19. Supra 2nd molar: 19.50
20. Occlusal line: 18.25
21. Sub 2nd molar: 16.00
But our skull is smaller than it should be!
To find out how big your tissue markers should be, pleaseuse the following formula:
To find out how big your tissue markers should be, pleaseuse the following formula:
(measurement) X 2 : 3
Once you place all your markers, let's go forward with the main facial features.
The Rynn Method of defining the Nose
Rynn, Wilkinson & Peters (2010) wanted a way to predict the position and size of the nose tip (pronasale) from the skull in a reproducible way for facial reconstruction. Their method uses a few simple bone measurements and then regression equations to predict:
From the profile, these are the landmarks we will use:
- how far down from the nasion the nose tip sits
- how far forward the tip sticks out
- how deep the tip is below the subspinale
- plus some guidance for nose width and base position
From the profile, these are the landmarks we will use:
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- Nasion (N) – the little dip between the eyes at the top of the nose.
- Rhinion (Rhi) – bottom end of the nasal bones along the midline.
- Subspinale (A / SSn / point A) – a point just under the nasal opening where the upper jaw curves in
- Acanthion (Ac / ANS) – the tip of the anterior nasal spine at the base of the nose opening
- Prosthion (Pr) – the most forward point of the upper front teeth area (alveolar bone, not the teeth).
Using these markers, Rhynn imagined a plane or a wall, which would cross both the nasion and the prosthion; he called this the nasion-prosthion plane. The whole deal with the size of the nose comes down to -- how far down in the plane is the tip of the nose, and how far out does it project?
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Two Problems, Two Solutions
For this calculation, measure and write down:
a = the distance from nasion to acanthion.
b = the distance from rhinion to subspinale.
First, let's find out how far from the nasion the nose tip will sit.
This distance uses the formula: a X 0.9 - 2mm
But because our skull is 2/3 of the size, we use the following calculation: a X 0.9 - 1.33 mm
Now, you have a range of where the nose tip should be:
a = the distance from nasion to acanthion.
b = the distance from rhinion to subspinale.
First, let's find out how far from the nasion the nose tip will sit.
This distance uses the formula: a X 0.9 - 2mm
But because our skull is 2/3 of the size, we use the following calculation: a X 0.9 - 1.33 mm
Now, you have a range of where the nose tip should be:
Draw this shape, well measured, on card paper.
You will be cutting your nose profile to add to your skull!
You will be cutting your nose profile to add to your skull!
The second calculation tells you how high the tip will be. With both of them together, you will have the beginning of a nose profile!
The regular skull measurement is b X 0.83 - 3.5 mm
But we use a different calculation to match our proportions!
Our formula will be: b X 0.83 - 2.33 mm
This shows how far forward the nose tip will be, considering the original plane we made between nasion and prosthion!
We have to find what is the most forward point between the nasion and the prosthion, which for us is the rhinion. Imagine a line that goes on the X axis, horizontally, as far away from the rhinion as our second calculation, then add a line vertically on the Y axis until it reaches the curved line from before.
This is how you find the nose tip!
The regular skull measurement is b X 0.83 - 3.5 mm
But we use a different calculation to match our proportions!
Our formula will be: b X 0.83 - 2.33 mm
This shows how far forward the nose tip will be, considering the original plane we made between nasion and prosthion!
We have to find what is the most forward point between the nasion and the prosthion, which for us is the rhinion. Imagine a line that goes on the X axis, horizontally, as far away from the rhinion as our second calculation, then add a line vertically on the Y axis until it reaches the curved line from before.
This is how you find the nose tip!
Nasal Tip Orientation
You are almost done with your paper shape!
The only thing you need is, how is the actual look of your nose? Does it point up, down, of is it flat?
The feature you have to look at is the nasal spine. The nasal spine is that whole pyramid shape right nder the nose, with the acanthium on the tip. The nasal spine acts like a tiny “direction indicator” for the nose:
The only thing you need is, how is the actual look of your nose? Does it point up, down, of is it flat?
The feature you have to look at is the nasal spine. The nasal spine is that whole pyramid shape right nder the nose, with the acanthium on the tip. The nasal spine acts like a tiny “direction indicator” for the nose:
✔ Long or downturned nasal spine → nose points DOWN
Stronger, longer spine = hooked or downward-tilting tip.
✔ Short or upturned nasal spine → nose points STRAIGHT or UP
Tiny, stubby spine = upturned or flat tip.
✔ Medium or straight nasal spine → “neutral” tip
Neither upturned nor downturned.
✔ Blunt or very short spine → Flat or softly upturned nose
✔ Sharp, thin spine → Narrow bridge, defined projection
Now, you are ready to cut a basic shape from the paper. Make sure you place it at the right distance in the very centre of the nose, and secure it with clay.
Width of Nose
Now that you have your paper shape secured, you have to figure out how wide is the nose.
The simplest way is this one -- it is used by many forensic artists worldwide:
Soft-tissue nose width ≈ 1.6–1.7 × the bony nasal aperture.
The simplest way is this one -- it is used by many forensic artists worldwide:
Soft-tissue nose width ≈ 1.6–1.7 × the bony nasal aperture.
But if you want to get really specific, there is a more advanced formula you can use:
WN = 15.28 + (1.012 × maximum width of the nasal aperture)
For us with our tiny dude, this calculation would be:
WN = 10.18 + (1.012 X maximum width of the nasal aperture)
Choose either of these to figure out the width of the nose!
Nose holes vary depending on background. European descent usually has narrow nose holes and a longer, higher bridge; African descent has rounder, larger holes, and a wider bridge. People of Southern and Eastern Asian will have a variation and a mixture somewhere in between these two, and people with a more diverse background will also have nosed that vary greatly. Fun fact: Like other physical characteristics, the holes changed as people adapted to different climates, so that in cold weathers they would protect the sinuses and keep the heat in, while in very hot weathers they would allow for better cooling and add more moisture to the air before it hits the lungs.
Attention -- The above measurements are based on a person of European ancestry, like our scanned skull; for the width of African populations, multiply by 1.8; for the projection, lower it by 2 or 3 mm. For Asian ancestry, multiply by 1.55 for the width, and lower the projection by 1 to 1.5 mm. Indian populations should be multiplied by 1.65 for the width, but the projection should remain the same as the Erupoean projection. The Turkish population is well-studied and quite different: the projection should be: 0.8x(Rhi-SSn) - 2mm, while the width should be multiplied by 1.7.
WN = 15.28 + (1.012 × maximum width of the nasal aperture)
For us with our tiny dude, this calculation would be:
WN = 10.18 + (1.012 X maximum width of the nasal aperture)
Choose either of these to figure out the width of the nose!
Nose holes vary depending on background. European descent usually has narrow nose holes and a longer, higher bridge; African descent has rounder, larger holes, and a wider bridge. People of Southern and Eastern Asian will have a variation and a mixture somewhere in between these two, and people with a more diverse background will also have nosed that vary greatly. Fun fact: Like other physical characteristics, the holes changed as people adapted to different climates, so that in cold weathers they would protect the sinuses and keep the heat in, while in very hot weathers they would allow for better cooling and add more moisture to the air before it hits the lungs.
Attention -- The above measurements are based on a person of European ancestry, like our scanned skull; for the width of African populations, multiply by 1.8; for the projection, lower it by 2 or 3 mm. For Asian ancestry, multiply by 1.55 for the width, and lower the projection by 1 to 1.5 mm. Indian populations should be multiplied by 1.65 for the width, but the projection should remain the same as the Erupoean projection. The Turkish population is well-studied and quite different: the projection should be: 0.8x(Rhi-SSn) - 2mm, while the width should be multiplied by 1.7.
Mouth Width and Lip Thickness
(Using the Stephan / Wilkerson / Gerasimov measurements)
These are the soft-tissue regressions regularly used in forensic facial reconstruction worldwide.
There are two questions we answer:
To find the indented middle of the lips (Stomion), find the subnasale on your skull, then the prosthion; the stomion will be around halfway between those two.
Stomion height = 45–55% of this distance.
For females: usually closer to 55% downward.
For males: closer to 50%.
This is true across all backgrounds and populations!
These are the soft-tissue regressions regularly used in forensic facial reconstruction worldwide.
There are two questions we answer:
- Where does the mouth sit vertically?
- How thick are the lips?
To find the indented middle of the lips (Stomion), find the subnasale on your skull, then the prosthion; the stomion will be around halfway between those two.
Stomion height = 45–55% of this distance.
For females: usually closer to 55% downward.
For males: closer to 50%.
This is true across all backgrounds and populations!
To find the location of the outer edges, we have to look at a couple new landmarks:
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Bottom edge of upper lip: between prosthion and incisal edge of the maxillary incisors (bitey part of front teeth)
Bottom edge of lower lip: between the infradentale and the supramentale. |
The thickness of each lip will be usually:
Upper lip: about 13–15 mm on males, 12–14 mm on females
Lower lip: about 15–17 mm on males, 14–16 mm on females
* The thickness is different for different backgrounds:
African ancestry: 2 to 4 mm thicker on both upper and lower
Asian: 1 to 2 mm thicker upper lip, 1 mm thinner lower lip
Finally, the width of the mouth usually lines up with the centre of the pupils in the eye. If the pupil location is hard to define, you can measure the distance between the two canines and multiply by 1.3, which would give you a good measurement. For people with African descent, the mouth will be a little wider, while for people with Asian descent, the mouth will be a little narrower on average.
Upper lip: about 13–15 mm on males, 12–14 mm on females
Lower lip: about 15–17 mm on males, 14–16 mm on females
* The thickness is different for different backgrounds:
African ancestry: 2 to 4 mm thicker on both upper and lower
Asian: 1 to 2 mm thicker upper lip, 1 mm thinner lower lip
Finally, the width of the mouth usually lines up with the centre of the pupils in the eye. If the pupil location is hard to define, you can measure the distance between the two canines and multiply by 1.3, which would give you a good measurement. For people with African descent, the mouth will be a little wider, while for people with Asian descent, the mouth will be a little narrower on average.
Shove the Eyeball In
Imagine a ball in a bowl of cereal. This ball is smaller than the cereal bowl, so it will rest a bit on one of the sides; but it is big enough to stick above the rim a bit.
This is how our eyeballs are. The eye is super precious, so it leans against the two stronger parts of the orbital cavity, which are the top (frontal) and the lateral (zygomatic). The bottom and the inner part are fragile and tend to get damaged easily, so the eye sits away from them.
Positioning the iris is interesting. The iris will sit exactly above the horizontal middle line of the opening. We don't have irises in our model, so that's easy. The pupil should look forward parallel to the Frankfort Plane, which is an imaginary plane crossing the top of the ear canal to the lowest part of the orbital cavity. The Frankfort Plane is a plane created to position the skull in a natural way; you will probably have yours looking up, which is OK. :)
The eye is actually suspended in the orbit cavity. Only about 3 to 4 mm stick out when looked at sideways -- or, 2 to 2.5 mm on our skull.
Summary of Positioning:
Eyeball (Globe) Size:
Eyeball Position:
Soft Tissue Variation
This is how our eyeballs are. The eye is super precious, so it leans against the two stronger parts of the orbital cavity, which are the top (frontal) and the lateral (zygomatic). The bottom and the inner part are fragile and tend to get damaged easily, so the eye sits away from them.
Positioning the iris is interesting. The iris will sit exactly above the horizontal middle line of the opening. We don't have irises in our model, so that's easy. The pupil should look forward parallel to the Frankfort Plane, which is an imaginary plane crossing the top of the ear canal to the lowest part of the orbital cavity. The Frankfort Plane is a plane created to position the skull in a natural way; you will probably have yours looking up, which is OK. :)
The eye is actually suspended in the orbit cavity. Only about 3 to 4 mm stick out when looked at sideways -- or, 2 to 2.5 mm on our skull.
Summary of Positioning:
Eyeball (Globe) Size:
- Standard: 24 mm diameter
- Same across sex, age (after childhood), and ancestry
- For 2/3-scale prints: 16 mm (that's why it's tiny)
Eyeball Position:
- The center of the eyeball sits behind the midpoint of the orbital opening, and above the orbital midline
- The globe touches:
- optic canal (back)
- orbital roof
- lateral wall
- The globe should project 3–4 mm beyond orbital rim (≈ 2–2.5 mm on your printed skulls)
Soft Tissue Variation
- Differences in eyelids, fat pads, and folds
- Eyeball size does not vary between populations
Reconstructing the Skull
PHEW. Now that you have all these different measurements and information, it's time to reconstruct our skull.
Start adding flat and thin pieces of clay, working around the markers and building up to them, just until the markers disappear. Try not to move the markers. Fill in the nose carefully.
When making the mouth, be careful not to cover the landmarks before adding the lips. A good idea is to mark the middle of the lips, the top edge and the bottom edge, as well as the width, with a pencil.
Last tip -- when you have everything sorted out, pull some pictures of people on your phone to use as reference.
Start adding flat and thin pieces of clay, working around the markers and building up to them, just until the markers disappear. Try not to move the markers. Fill in the nose carefully.
When making the mouth, be careful not to cover the landmarks before adding the lips. A good idea is to mark the middle of the lips, the top edge and the bottom edge, as well as the width, with a pencil.
Last tip -- when you have everything sorted out, pull some pictures of people on your phone to use as reference.
