Anthropometry And Its Role In Restoring The Natural Hairlines
Anthropometry refers to the measurement of the physical properties of the human body and racial differences.
Today, anthropometry plays an important role in industrial design, clothing design, ergonomics and architecture where statistical data about the distribution of body dimensions in the population are used to optimize products.
The art of Hairline Restoration is the single most important factor for creating the natural looking hair transplant. No one can tell the difference between transplanted or non-transplanted hair if hairline looks natural.
To understand the hairline, one must have reviewed 100s of natural non-receded hairlines. One should also have complete knowledge of different racial hairlines and know the reasoning why they are racially so unique.
The underlying differences in facial bony structures and facial features in different races, determine the unique shape of the hairlines.
Knowledge Of The Facial Hight And Widths ( Anthropometry ) And Its Role In Restoring The Receded Or Lost Hairlines
Vertical Facial Dimensions
The face generally divided into three parts. The lower part of the face is the largest in all the races and the upper part is the smallest.
- Upper part
- Middle part
- Lower part
The upper part of the face is between hairline and the eyebrows. The height of the upper part is smallest of all the three facial heights. In Caucasians and Asians, the height of the upper part is almost same, averages about 5.70 cm. In Afro, it’s 0.5 cm more than the Caucasians and Asians and on an average its 6.20 cm. As the upper part of the face in afro has more height, so does the hairline. On an average Afro hairline is 0.5 cm higher than Caucasians and Asians.
The middle part of the face is between eyebrows and the lower base of the nose. The height of the middle part of the face is almost same in all three races, it’s an average 6.25 cm.
The lower part is between the lower base of the nose and the chin. The height of the lower part of the face is largest of all the three facial heights in all the races. In Caucasians and Asians, the height of the lower part is almost same, averages 7 cm. In Afro, the height of the lower part is 0.5 cm more than the Caucasians and Asians with an average of 7.50 cm.
Horizontal Facial Dimensions
In horizontal facial dimensions, four measurements are important.
- Width of the head
- Width of the eyes
- Width of the mandible
- Width of the jaw
Generally, for every race, the head is the widest, mandible is less wide than the head and jaw is the less wide than mandible. In Asians, Head, Mandible and Jaw widths are the largest among all three races. In Afro, Head, Mandible and Jaw widths are smallest among all three races. In Caucasians, Head, Mandible and Jaw widths are in the mid range, among all the three races.
The only width of the eyes is widest of all the races for Africans, while head, mandible and jaw widths are smallest of all the race for Africans. The width of the eyes is smallest for Caucasians. The Width of eyes is in mid range for Asians among all the races.
Widths of The Head, Mandible and Jaw Are Responsible for Different Facial Shapes
Square Facial Shape among African
In Africans, the width of the head, mandible and jaw are smallest among all the races. The width of the head averages at 15 cm. The mandible width in Africans is an average 14.5 cm, 0.5 less than the width of the head. The width of the jaw is 10.5 cm, 4 cm less than the mandible. The general appearance of Africans face looks like a square due to the smallest head width and relatively minimum reductions in widths from head to the mandible and mandible to the jaw, among all the races.
Triangular Facial Shape for Asians
In Asians, the width of the head, mandible and jaw are the widest among all the races. The width of the head averages at 16 cm. The mandible width is 15.35, an average 0.65 cm less than the head width. The width of the jaw is 10.85, an average 4.5 less than the mandible. The general appearance of the face in Asians look like triangular due to the widest head width and increased reduction in the width of mandible and jaw relative to the head.
Elliptical Facial Shape for Caucasians
In Caucasians, the width of the head, mandible and jaw are in the mid range, among all the races The head width on an average is 15.25 cm. The mandible width is 14.75 an average 0.5 cm less than the head width. The width of the jaw is 10.65, an average 4.10 cm less than the mandible. The general appearance of the face looks like elliptical due to a less drastic reduction of mandible and jaw width relative to the head in comparison to Asians and more than Africans.
Width Of Eyes Are Generally Responsible For The General Shape Of The Hairline
Broder Wide Relatively Flat Hairline In Africans
The width of the eyes is widest of all the races for Africans, 10 cm. Part lines almost always correspond with the eyes width. The widest part of eyes are medically referred as outer Canthus and part Lines are medically referred as outer canthal plane. As the eyes width is the widest for African, it leads to wider broader hairline.
Round Hairline For Asians
The width of eyes in Asians is in the mid-range among all the three races, 9.5 cm. As the width of eyes is more than Caucasians and less the African, it mostly transforms the hairline into a round shape.
Oval Hairline For Caucasians
The width of the eyes is smallest in Caucasians among all the races, 9 cm. The corresponding part line in Caucasians gives a relatively oval shape to the hairline.
Skull Shape Role In Hairline Aesthetics
First of all, a horizontal level is established at the level of eyebrows on the front, top of the ears on the sides and posterior pole of the skull on the back. Skull moves straight upward circumferentially from this level for an average 5-6 cm with 15 degrees inward inclination. Above the vertical part, Skull is Dome shaped and this part is called calvarium. An average height of the calvarium is 3-4 cm. Where the vertical part of the Skull end, it curves inward for an average 1 cm, this part is called lower transition zone of the calvarium. After the transition zone, calvarium part of the Skull moves up 2-2.5 cm at an average 45 degree, at this point skull again curves inward to create an upper transition zone and become flat at the top.
Anthropometric studies found, the normal average 3-4 cm height of the calvarium adds to the natural attractiveness of the face if especially the hairline starts at the beginning of calvarium, it gives the natural bounce to the hair.
If the restored hairline starts in the middle of the calvarium or even further higher, it makes the hair looks flat. Hairline restoration is and should restore the lost aesthetic proportion of the face and should add to individual attractiveness rather just adding the hair.
Hairline Creation Based on Bony Facial Dimensions
To create frontal hairline inconsistent with person racial features does not look natural. Knowledge of differences among the underlying facial bony structure and their measurements are extremely important to restore the unique individual hairlines.
Hairline is based on two important points.
- Frontal Midpoint
- Part-line of the hair
There are two criteria based on Facial Dimensions to mark the Frontal Midpoint.
First Criteria for Marking the Frontal Midpoint
The Average height of the vertical part of the forehead is 5.70 cm in Asians and Caucasians. In Africans, it’s 0.50 cm higher. The Vertical part of the forehead moves up from eyebrows at average negative 15 degree angle and ends into lower transition zone of the calvarium. The height of lower transition zone of calvarium is an average 1 cm. Frontal Midpoint is marked in the middle of this transition zone. These general measurements give an idea about the height of the frontal hairline from the eyebrows. Based upon the above general measurements average height of the frontal hairline in Caucasian and Chinese is at an average 6.0 cm and in Africans is at an average 6.5 cm high from the eyebrows.
Second Criteria for Marking the Frontal Midpoint
Facial height is measured from eyebrows to the chin, if it’s 13 cm, take half of that, 6.5 cm, to mark the frontal midpoint.
Part-Line Of The Hair
The role of outer bony rims of the eyes in locating Part-Line Of The Hair
The width of the eyes plays very important role. A vertical line is drawn at the outer bony rim of the eyes, join this vertical line with another line at 90 degrees tangential line running from front to back. Drop this tangential line at right angle to the vertical line. Where this tangential line touches the skull, it’s the part line of the hair, also called outer canthal plane. Once the part line is located, next is to mark the individually unique aesthetically attractive joining point at part line, to the frontal midpoint.
How To Establish Aesthetically Attractive Front Hairline Joining Point On Part Line
A vertical line is drawn in front of the ear, where this line intersects with the part line, it is marked. From this marked point, mark another point 2 cm in front of it on the same level. Join the frontal midpoint to this point to restore the lost frontal hairline. It creates a shape of a semicircle. The average length of the hairline semicircle is 14 cm. The average length of half of this semicircle from the frontal midpoint to the point marked on hair part line is 7 cm, If this length ranges between 6 to 8 cm, the front hairline aesthetically looks extremely pleasing. Depending on different racial head widths, it creates an Oval hairline for Caucasians, round for Asians and broad flat hairline for Africans. The part line joining point can be fine tuned based on unique individual facial features.
Restoring The Temporal Hairline.
In the temple area the non-receded temporal hairline start at the part line, an average 3 cm in front of the pretragal vertical line, the temporal hairline extend down and forward at 45 to 60 degree angle and stops an averages 2.5 cm above the outer limit of eyebrows, this part is medically referred as temporal peak, from this point temple hairline extend down and backward at 45 to 60 degree angle and continue with the front part of sideburns.
Temple hairline also recedes in hair loss. Temporal hairline recedes backward in Class 2-5 hair loss. In Class 6 to 7 hair loss, temporal hairline also recedes downward from the part line.
Restoring the temporal hairline compliment the frontal hairline. If the donor area allows, this lost temporal hairline can be restored. Draw a vertical line just in front of the ear, where this vertical line intersects the part line area, mark that point, mark another point 2 cm in front of it. Connect the receded temporal hairline to this point.
To restore the temporal peaks, first, try to find the traces of temporal peak, and restore it.
If there is no trace of the temporal peak, mark the new temporal peak. The average height of the temporal peak is 2.5 cm above the eyebrow level. Draw a first vertical line from the outer bony rim of the eye. Draw another second vertical line 2cm behind the first drawn vertical line. On the second line average 2.5 cm above the eyebrows level is place to restore the lost temporal peaks.
Once the hairline is drawn based on individual facial features and utilizing the anthropometric knowledge of the underlying bony structure of the skull and face, the marked hairline rather just adding the hair, adds attractiveness to the existing features.
This marked hairline is reviewed in the mirror first by standing behind the client and then standing on each side of the client. The hairline has subtle natural irregularities and is still even and symmetrical when viewed from the front and sides. From side view hairline should look horizontal and with very little forward lower inclination. The Part line meeting point should never be lower than the Frontal midpoint on profile view. Front, three-quarter and side profile pictures of the drawn hairline are taken and reviewed with the client. Client previous pictures without hair loss are also reviewed. Minor Adjustments are made on the request of the client if needed
Once the final hairline is decided after the discussion with the client. Transition zones of a gradual increase in the density are marked. A line is marked 3-4 mm behind the decided hairline, single hair follicular units are planted in this zone in an irregular pattern. An average low density of 20 single hair follicular units per cm square is achieved. Another line is drawn 3-4 mm behind the single follicular units. An average density of 30-40 single follicular units per cm square is achieved in this zone. In these two zones of single hair follicular units, perpendicular sites at 10-20 degree angle with forward natural fans out direction are made, as the hair naturally move away from frontal midpoint toward the part line. Another 1 cm deep zone is drawn behind these two zones of single hair follicular units, in this zone, two hair follicular units are used in perpendicular sites at an average 15-30 degree angle. Behind the two hair follicular units zone combinations of two and three hair follicular units are used. As this zone move back from frontal area to mid-scalp area, the angles of the sites gradually increase from 30 to 60 degree.
Symmetrical irregularities are created just like the frontal hairline. Perpendicular sites at 0-10 degree angle are created in down and backward direction. Temple hairline is restored by single hair follicular units.
Hair Restoration For Different Classes Of Hair Loss Based On Anthropometry
Number 1, hair restoration on illustrations are more proportionate and utilize the anthropometry knowledge to restore aesthetically pleasing hair restoration and restore the lost natural facial proportions.
Number 2, hair restoration on illustrations are at higher levels and does not take the advantage of calvarium height to provide aesthetically pleasing results.
Number 3, Most Common Mistake In Hair Restoration
Front hairline should not chase the receded temple hairline, below the part line. Most common aesthetically bad hairlines can all together can be avoided, if the frontal hairline simply stays circumferentially horizontal at part line level.
Anthropometry knowledge gives the insight about the uniqueness of hairline in different races and allows the hair transplant surgeon to restore individuality unique hairlines and provides aesthetically pleasing results.