Content uploaded by Márcio De Menezes
Author content
All content in this area was uploaded by Márcio De Menezes on Jun 20, 2016
Content may be subject to copyright.
611
V.R. Preedy (ed.), Handbook of Anthropometry: Physical Measures
of Human Form in Health and Disease, DOI 10.1007/978-1-4419-1788-1_32,
© Springer Science+Business Media, LLC 2012
Abstract Several basic and clinical disciplines are interested in the quantitative assessment of the
dimensions of human facial soft-tissue structures (eyes, nose, mouth and lips, chin, ears), and of their
reciprocal spatial positions and relative proportions. Anatomical and anthropometric descriptions,
medical evaluations (genetics; maxillo-facial, plastic and esthetic surgery; dentistry), forensic medi-
cine, they all need reference three-dimensional data collected on healthy, normal individuals selected
for sex, age, ethnic group, to be compared to those obtained on the single patient. Data collection
should be made non-invasively, rapidly, simply, directly on the subjects using low-cost instruments.
All data should be digital, thus entering computerized data bases that can be used to visualize and
simulate treatment. Currently, in clinical investigations and research classic direct anthropometry is
being replaced with various three-dimensional image analyzers. Optical, non-contact digitizers
(mainly, laser scanners and stereophotogrammetric devices) perform a fast digitization of the face,
providing a detailed analysis of the soft-tissue surface. Contact instruments (electromagnetic and
electromechanic digitizers) digitize discrete soft-tissue facial landmarks. Subsequently, landmark
coordinates are used into mathematical and geometric models of the face, and angles, distances and
ratios similar to those measured in conventional anthropometry can be obtained. Additionally, mul-
tivariate methods of analysis, obtained either from geometric morphometry or from other analytical
methods, could be used. Overall, computerized instruments seem suffi ciently reliable, simple and
fast to be used also within clinical contexts, thus providing useful quantitative information to allow
a better patient care, without submitting the subjects to potentially harmful procedures.
Abbreviations
3D Three-dimensional
SD Standard deviation
CAD Computer aided design
CAM Computer aided machinery
Chapter 32
Three-Dimensional Facial Morphometry:
From Anthropometry to Digital Morphology
Chiarella Sforza , Claudia Dellavia , Marcio De Menezes , Riccardo Rosati , and Virgilio F. Ferrario
C. Sforza ()
Functional Anatomy Research Center (FARC), Laboratorio di Anatomia Funzionale dell’Apparato
Stomatognatico (LAFAS), Dipartimento di Morfologia Umana e Scienze Biomediche “Città Studi,”
Facoltà di Medicina e Chirurgia, Università degli Studi di Milano , via Mangiagalli 31 ,
I-20133 Milano , Italy
e-mail: chiarella.sforza@unimi.it
612 C. Sforza et al.
32.1 Introduction
In man, the head is the most complex structure of the body. It accommodates the central nervous
system, the eyes and ear structures, and the fi rst parts of the digestive and respiratory apparatuses. It
is characterized by the face. Communication and interaction with the environment, as well as per-
sonal identifi cation, all depend on the face (Sforza and Ferrario 2006 ; DeAngelis et al. 2009 ) .
Anthroposcopy (observation) and anthropometry (measurement) are currently used to analyze
facial morphology in several basic and applied fi elds that cover a wide range of life and medical
sciences (Sforza and Ferrario 2006 ) . Both play an important role in the diagnosis of several dys-
morphic syndromes, especially for the assessment of borderline patients (Douglas et al. 2003 ;
Hammond et al. 2004 ; Dellavia et al. 2008 ; Maal et al. 2008 ; Fang et al. 2008 ; Schwenzer-Zimmerer
et al. 2008 ) .
Apart from expert observation of facial characteristics, quantitative assessments of the dimen-
sions of facial soft-tissue structures (such as eyes, nose, mouth and lips, chin, and ears), their recipro-
cal spatial positions and relative proportions are important components in the clinical analysis of
patients with facial alterations and deformities, as well as in treatment planning, and in the fi nal
evaluation of results (Yamada et al.
2002 ; Hajeer et al. 2004 ; Hammond et al. 2004 ; White et al.
2004 ; Dellavia et al. 2008 ; Maal et al. 2008 ) .
Indeed, a global, three-dimensional, quantitative assessment of craniofacial characteristics may
help in clinical diagnosis. This analysis should consider both the hard- and the soft-tissue structures.
Clinical assessments for surgical (maxillo-facial, plastic, and esthetic) or dental (orthodontics and
prostheses) treatments should combine the conventional radiographic analyses of the skeleton with
evaluations of the soft-tissue structures, thus providing a complete evaluation of any patient. At all
occasions, patient data should be compared to those of healthy subjects of the same age, sex, race,
and ethnic group.
Classic direct anthropometry has greatly helped clinicians in the past (Farkas, 1994 ) , but, pres-
ently, the advent of digital techniques for the imaging of the facial skeleton should be combined by
some new methods for soft-tissue facial imaging and measurement (Table 32.1 ).
Currently, in clinical investigations and research, classic direct anthropometry is being coupled
and even replaced with various three-dimensional image analyzers. These instruments can be divided
into two main categories: optical, non-contact digitizers, and contact instruments. In the current
chapter, classic anthropometry will be reviewed, and advantages and limitations of the modern facial
digitizers will be presented and discussed.
Table 32.1 Key points: conventional anthropometry versus digital instruments
Digital instruments
Conventional
anthropometry Optical Contact
Cost Negligible Expensive (8–10 times higher than
contact instruments)
Limited
Patient time Long Negligible Limited
Off-line operator time Negligible Long Negligible
Setting Everywhere Often laboratory or clinic only Easy transport
Information content Low High Medium to low
Adding new measurements,
correcting errors
Impossible Easy Diffi cult
Assessment of anatomical
landmarks
Direct (inspection/
palpation)
Digital (inspection only) Direct (inspection/
palpation)
The main differences between conventional anthropometry and digital instruments are listed
61332 Three-Dimensional Facial Morphometry: From Anthropometry to Digital Morphology
32.2 Direct Facial Anthropometry
Direct anthropometry has been the fi rst method for the in vivo, quantitative, three-dimensional
assessment of the human face, and it still continues to be used in several basic and applied fi elds that
cover a wide range of life and medical sciences (Farkas 1994 ) . Conventional, direct anthropometry
is currently considered the gold standard for in vivo assessments: it is simple and low cost; it is non-
invasive; and it does not require complex instrumentation (Farkas 1994 ; Zankl et al. 2002 ) .
A further advantage of conventional anthropometry is the existence of normal databases for
almost all craniofacial measurements, at least for white Caucasians (Farkas 1994 ; Zankl et al. 2002 ) ,
whereas norms for other ethnicities are more scanty (Farkas 1994 ; Farkas et al. 2005 ) .
At the same time, direct anthropometry is time consuming, it necessitates very well trained and
experienced examiners, and it is very demanding for both the clinician and the patient (Douglas et al.
2003 ; White et al. 2004 ) . Each facial measurement (linear distance or angle) is taken individually, a
long procedure prone to error (Aldridge et al. 2005 ) , and no permanent record of the facial arrange-
ment is maintained. Therefore, missing values, miscalculations, or reading errors cannot be cor-
rected once the subject has been released.
Furthermore, direct anthropometry does not provide digital coordinate data that could be used to
measure new features, or to extract more complex calculations (surface and volume estimations,
analyses of symmetry, and form and shape quantifi cation) (Shaner et al. 2000 ; Douglas et al. 2003 ;
Ferrario et al. 2003 ; Hammond et al. 2004 ; White et al. 2004 ; Mori et al. 2005 ; Fang et al. 2008 ;
Schwenzer-Zimmerer et al. 2008 ) .
An ideal method for the quantitative evaluation of the patients should combine:
Non-invasive, low-cost instruments that could directly be carried off-site to meet the patients •
A fast, simple, data-collection technique that provides three-dimensional digital data and a per-•
manent record of the facial morphology
Computerized reference databases collected from healthy, normal individuals of same sex, age, •
and ethnic group as the patients
The use of computerized techniques for visualization, simulation, and quantitative assessment of •
the treatment
Most of these requirements are currently met by digital, computerized anthropometry. At the
same time, several investigations performed both in vivo and on inanimate models also compare
conventional and computerized anthropometric data to assess if they could be, at least in part,
exchanged, thus opening new possibilities to basic researchers and clinicians (Sforza and Ferrario
2006 ) . Good results have been obtained for both global facial analyses, and for the assessment of
selected parts of the face (e.g., soft-tissue orbital features, facial profi le measurements, and mouth
and nasal dimensions) (Sforza and Ferrario 2006 ; Weinberg et al. 2006 ; Ghoddousi et al. 2007 ;
Wong et al.
2008 ; Ozsoy et al. 2009 ; Plooij et al. 2009 ) . Overall, the conventional anthropometric
and digital data seem suffi ciently interchangeable, at least from a practical, clinical point of view.
32.3 Instruments for Three-Dimensional Digital Morphometry
Two main groups of instruments can currently be used for computerized, soft-tissue three-dimensional
facial anthropometry: optical, non-contact instruments (laser scanners, three-dimensional range
cameras, optoelectronic instruments, stereophotogrammetry, and Moiré topography) and contact
instruments (electromagnetic and electromechanical digitizers and ultrasound probes).
614 C. Sforza et al.
All these instruments are non-invasive, not potentially harmful (apart from some limitations for
laser light, but that seem to have been overcome in the last generation of laser scanners), and do not
provoke pain or discomfort to the subjects.
Both kinds of instruments have advantages and limitations that should be considered according to
the investigated problem and the human resources (Table 32.2 ).
32.3.1 Optical Instruments
The most used instruments of this category are laser scanners and stereophotogrammetric systems.
Laser scanners illuminate the face with a laser light source, and digital cameras capture the refl ected
light; the depth information is obtained by triangulation geometry (Majid et al. 2005 ; Hennessy et al.
2006 ; Schwenzer-Zimmerer et al. 2008 ) . During data acquisition, either the face (with a rotating
stool) or the laser light moves to scan the entire surface. In the fi rst scanners, the laser light was not
safe for the eyes, but current instruments are stated to be not dangerous. Accuracy and resolution are
reported between 0.5 and 1 mm, and approximately 10 s are necessary for a complete scan. Critical
parts of the face are the ears, the nostrils, and the chin. Shadows, local facial characteristics (hairs
and nevi), and a dark complexion may hamper the digitization (Majid et al. 2005 ) .
Stereophotogrammetry uses a light source (either patterned or conventional) to illuminate the face,
and two or more coordinated cameras record images from different points of view (Fig. 32.1 ) (Majid
et al. 2005 ; Ghoddousi et al. 2007 ; Sawyer et al. 2009 ; Wong et al. 2008 ; Plooij et al. 2009 ) . A previ-
ous calibration, made with objects with known geometric characteristics, supplies the mathematical
information to obtain a stereoscopic reconstruction of the face (Fig. 32.2 ). The system can also record
facial texture, and combines the three-dimensional information with an accurate reproduction of all
facial characteristics (Fig. 32.3 ). Accuracy and resolution are around 0.5 mm, and 2 ms can be suffi -
cient for a facial scan. Surface artifacts, limited lateral coverage, and shadows effects are limitations
that stereophotogrammetry shares with laser scanning, but they seem of relatively less importance.
Figure 32.4 shows an example of facial reconstruction by stereophotogrammetry. The fi ner the
mesh is the better is the reconstruction. Some artifacts (low-resolution scan) can be found under the
chin and the ear, and inside the nostrils.
Both these methods supply a wealth of data for each face (typically, laser scanning can describe
the face with approximately 80,000 points, Hennessy et al. 2006 , whereas stereophotogrammetry
can obtain 300,000–450,000 surface points, Weinberg et al. 2004 ) , thus allowing a complete assess-
ment of both qualitative and quantitative features that are permanently recorded into the computer.
Also, the time necessary to obtain a complete facial scan is negligible, thus reducing or abolishing
motion artifacts, a feature particularly important for the assessment of children and disabled persons.
In this aspect, stereophotogrammetry performs better than laser scanning, with appreciably faster
scan times.
Both instruments have relatively lengthy post-processing times because the different facial pic-
tures must be mathematically combined to obtain the three-dimensional surface. This time strictly
depends on the host computer. Another limitation of these optical methods is the cost of the instru-
mentation, and, in some instances, the dimensions and need for special settings that cannot be taken
away to meet the patients at other locations. Portable stereophotogrammetric instruments and hand-
held laser scanners have been developed, and used for facial analysis outside laboratory or clinical
facilities (Douglas et al. 2003 ; Schwenzer-Zimmerer et al. 2008 ) . Resolution and accuracy are around
1 mm, and are considered adequate for basic and clinical studies (Hennessy et al. 2006 ) , even if
motion artifacts may often limit their use.
61532 Three-Dimensional Facial Morphometry: From Anthropometry to Digital Morphology
Table 32.2 Principal characteristics of currently used computerized, three-dimensional, soft-tissue facial digitizers
Motion artifacts Post processing Landmarks Information Critical parts of face Dimensions Cost
Optical scanners
Laser scan Limited (approx.
scan time 2 s)
Lengthy
(it depends on
the host
computer)
Identifi ed only on the
digital image; no
physical compression
All surface Imaging hairs impossible;
diffi cult imaging of
nostrils, ears, and
neck
Transportable Expensive
Stereo-
photogrammetry
Negligible (approx.
scan time 10 ms)
Lengthy
(it depends on
the host
computer)
Identifi ed on both the
digital image and
directly on the skin; no
physical compression
All surface
and texture
Potential problems with
hairs; diffi cult
imaging of ears
Often bulky but
transportable
Expensive
Contact instruments
Electromagnetic
digitizer
Present (approx. scan
time for 50
landmarks 60 s)
Fast Directly identifi ed on
the skin; possible
physical compression
Only selected
landmarks
Potential problems with
metal and electromag-
netic fi elds (orthodon-
tic brackets)
Movable with
ease
Limited
Electromechanic
digitizer
Present (approx. scan
time for 50
landmarks 60 s)
Fast Directly identifi ed on the
skin; possible physical
compression
Only selected
landmarks
Movable with
ease
Limited
The main differences between the most used digital instruments for facial anthropometry are listed
616 C. Sforza et al.
Although the optical instruments supply a detailed recording of the soft-tissue facial characteris-
tics based on a large quantity of soft-tissue points, they do not individualize single anatomical land-
marks. Landmarks are recognized on the digital reconstructions of the face, using all computer tools
of zoom, rotation, and translation (of the image) (Hammond et al. 2004 ; White et al. 2004 ) . This
procedure can result in some discrepancies between the actual anatomical landmarks and their digi-
tal counterparts because some landmarks cannot be obtained by simple inspection, and only facial
palpation allows their identifi cation (for instance, gonion). Therefore, a number of standard land-
marks (and subsequent measurements) should be excluded from the analysis (Weinberg et al.
2004 ;
White et al.
2004 ) .
Fig. 32.1 Schematic
diagram of a stereophoto-
grammetric set. The main
components of a stereophoto-
grammetric instrument are
shown
Fig. 32.2 Example of facial
reconstruction made by
stereophotogrammetry.
Surface rendering of a
three-dimensional facial
reconstruction made by
stereophotogrammetry
61732 Three-Dimensional Facial Morphometry: From Anthropometry to Digital Morphology
Considering that stereophotogrammetry also collects the soft-tissue texture, for this technique
some landmarks can be directly labeled on the face before data acquisition (Fig. 32.3 ) (Weinberg
et al. 2004 ) . Unfortunately, the procedure cannot be undertaken with most laser scanning systems
because the ink used for the mark is not digitized by the scanner. Previous labeling also improves
accuracy in landmark recognition (Weinberg et al. 2004 ) .
The optical instruments need no physical contact with the skin, thus eliminating the risk of cuta-
neous compression, and of potential injuries during measurements (Douglas et al. 2003 ; Majid et al.
2005 ; Sawyer et al. 2009 ) .
32.3.2 Contact Instruments
Ultrasound probes, and electromagnetic and electromechanic digitizers are among the most used
contact instruments. They digitize single, selected, facial landmarks, thus reducing the information
obtained from each face, but providing the coordinates of facial features that directly correspond to
anatomical and anthropometric structures (Ferrario et al. 1998, 2003 ; Sforza et al. 2007, 2009 ;
Dellavia et al. 2008 ; Ozsoy et al. 2009 ) .
Fig. 32.3 Facial reconstruc-
tion made by stereophoto-
grammetry with the relevant
facial texture. A set of
soft-tissue facial landmarks
is also identifi ed. The fi nal
image produced by
stereophotogrammetry
is shown
618 C. Sforza et al.
Ultrasound probes use acoustic waves in the megahertz frequency domain, whereas electromag-
netic and electromechanic digitizers are based on electromagnetic waves. The instruments have no
invasiveness and pose no biological hazard.
For the face, ultrasound images the skeletal surface and its soft-tissue cover (Sforza and Ferrario
2006 ) . While the method is widely used for prenatal, intrauterine imaging and diagnosis, and three-
dimensional reconstructions of the fetal face are a current clinical practice, its application for post-
natal facial morphometrics is limited. Currently, it is used only for the in vivo measurement of the
thickness of facial soft-tissue cover.
Electromagnetic and electromechanic digitizers provide the three-dimensional coordinates of
landmarks that are actually touched one by one by the instrument’s stylus (Ferrario et al. 1998, 2003 ;
Sforza et al.
2007, 2009 ; Dellavia et al. 2008 ; Ozsoy et al. 2009 ) . The fi eld of the electromag-
netic digitizer used in our laboratory (3Draw, Polhemus Inc., Colchester, VT) provides a three-
dimensional working volume (three spatial coordinates) of approximately 30 × 30 × 76 cm; it has a
resolution of 0.005 mm/mm range, and an accuracy of 0.08 mm. The electromechanical digitizer
(Microscribe G2, Immersion Corporation, San Jose, CA) is a multi-joint-arm digitizer, with an accu-
racy of 0.38 mm in a 127-cm workspace. Within each joint, an optical encoder works with a micro-
chip to send the joint angle to a host computer; the three-dimensional coordinates of the stylus are
therefore provided.
A set of facial landmarks is previously marked on the face of the subject; landmarks are identifi ed
by inspection or palpation (as in conventional anthropometry), and are marked with a small black
dot. Subsequently, the subject is positioned within the working volume of the instrument, and asked
to stay motionless, while the operator gently touches the facial landmarks one by one using a stylus
Fig. 32.4 Facial reconstruc-
tion made by stereophoto-
grammetry with mesh
rendering. Under the chin, a
small-size defect in the mesh
reconstruction can be seen
61932 Three-Dimensional Facial Morphometry: From Anthropometry to Digital Morphology
connected to the digitizer. With both instruments, data collection for a set of 50 landmarks needs
50–60 s for each subject (Ferrario et al. 1998 ) , and motion artifacts could occur.
The principal limitations of the instruments are the reduction of information, and the time neces-
sary for data acquisition. The acquisition of only single, selected landmarks impedes the production
of lifelike facial models (Fig. 32.5 ) (Ferrario et al. 1998 ) , and the application of the method as a com-
munication tool is diffi cult, in particular with the patients (Hajeer et al. 2004 ) . Also, no permanent
records of the facial appearance are obtained, and it is not possible to correct the position of a land-
mark off-line, or to introduce new landmarks.
Data acquisition time is extremely long when compared to that necessary for an optical facial
scan (even if it is remarkably short when compared to conventional anthropometry, Farkas
1994 ;
Douglas et al.
2003 ) , and movements of facial muscles (especially around mouth and eyes), as well
as global head movements, may occur during digitization.
The calibration of the electromagnetic instrument can be altered by electromagnetic interferences
and metal objects. To avoid interferences with the electromagnetic fi eld, data collection should be
performed in a controlled environment, with all electromagnetic devices (e.g., computers, video
recorder, power supply of the digitizer, and mobile telephones) and metal objects positioned at a
minimum of 2 m from the digitizer (Ferrario et al. 1998 ) . Also, the subject should not wear a metallic
object on the head (for instance, voluminous earrings), and the operator should not wear a metallic
object or a watch on the arm that uses the stylus.
In contrast, the electromechanic instrument does not need any special environment for
acquisitions.
Fig. 32.5 Example of facial
reconstruction made by
contact instruments. All
nodes of the image corre-
spond to facial landmarks and
some of them are labeled for
clarity (tr, trichion; ex,
exocanthion; n, nasion; prn,
pronasale; ala, ala nasi; sn,
subnasale; ch, cheilion; sl,
sublabiale; go, gonion; pg,
pogonion). A schematic
facial diagram obtained from
a 50-landmark digitization
620 C. Sforza et al.
Both instruments provide the fi les of the three-dimensional ( x , y , z ) coordinates of the facial
landmarks, and computer programs devised in the laboratory are used for all the subsequent off-line
calculations. Using both digitizers, Ferrario and co-workers (Ferrario et al. 1998, 2003 ; Sforza et al.
2007, 2009 ; Dellavia et al. 2008 ) have analyzed more than 1,000 faces of healthy, normal persons
from childhood to old age, together with a 100 faces of disabled or diseased persons; overall, the
method seemed suffi ciently reliable for anatomical and clinical investigations of selected facial
characteristics. Some applications of their method are shown in other chapters of the current book.
In their investigations, Ferrario and co-workers (Ferrario et al., 2003 ; Sforza et al. 2007, 2009 ;
Dellavia et al. 2008 ) focused on the analysis of facial measurements similar to those obtained by
conventional anthropometry (linear distances and angles), as well as on estimates of the volumes
and surface areas of selected parts of the face (mouth and lips, nose, eyes, and ears). Additionally,
they provided quantitative evaluations of facial symmetry and shape, independently from size
(Sforza and Ferrario 2006 ) .
In general, contact instruments are less expensive than optical ones (approximately 8–10 times
less), and they can be moved with ease from the laboratory to meet the subjects at alternative loca-
tions; additionally, they directly provide the three-dimensional coordinates of the anatomical land-
marks of interest, without any additional off-line calculations (Ozsoy et al. 2009 ) .
32.4 From Anatomical Landmarks to Digital Morphology
Landmarks represent the link between conventional and digital anthropometry (Sforza and
Ferrario 2006 ) : conventional anthropometry identifi es soft-tissue landmarks, and places some
instrument (calipers or protractors) over them. Distances are obtained between a pair of land-
marks; angles are comprised among three landmarks (Farkas 1994 ) . The entire surface comprised
between the landmarks is neglected, apart from observation of specifi c features (anthroposcopy).
Fundamentally, digital anthropometry collects a set of digital landmarks from the soft-tissue sur-
face, and uses their spatial x , y , z coordinates as endpoints for calculations based on Euclidean
geometry: linear distances and angles similar to those provided by conventional anthropometry
are computed.
Together with these classic measurements, mathematics and geometry allow the assessment of
more complex characteristics from the same set of landmarks used by conventional anthropometry:
estimations of volumes and surfaces, analyses of symmetry, and detailed assessments of shape inde-
pendently from size (Ferrario et al. 1998, 2003 ; Shaner et al. 2000 ; Douglas et al. 2003 ; Hajeer et al.
2004 ; Aldridge et al. 2005 ; Mori et al. 2005 ; Sforza et al. 2007, 2009 ; Dellavia et al. 2008 ; Fang et al.
2008 ; Sawyer et al. 2009 ; Schwenzer-Zimmerer et al. 2008 ) .
Additionally, the enormous amount of data collected by some of the digitizers allows detailed
assessments of all inter-landmark surfaces, for instance, with the development of pattern recognition
algorithms (Hammond et al. 2004 ; Hennessy et al. 2006 ) .
In our laboratory, we currently identify 50 soft-tissue landmarks on each face (Ferrario et al.
1998 ) . The landmarks are located on the forehead, eyes, nose, lips and mouth, chin, ears, and lateral
facial surface (Table 32.3 , Fig. 32.3 ). Twelve of them are on the midline, whereas 19 are identifi ed
on each hemi-half of the face. This set of landmarks was chosen to be used with the contact instru-
ments, and it is a good compromise between a suffi ciently detailed individuation of the anatomical
characteristics of the face and digitization time. Currently, the use of an optical, stereophotogram-
metric instrument allows the selection of an even wider set of landmarks, according to the problem
being investigated. Nevertheless, the use of a standard set of landmarks allows the consistent assess-
ment of subjects in both longitudinal and cross-sectional studies.
62132 Three-Dimensional Facial Morphometry: From Anthropometry to Digital Morphology
32.5 Applications to Other Areas of Health and Disease
Basic human research has obtained valuable results using three-dimensional anthropometry, and
several anatomical studies have quantitatively described normal facial growth, development, and
aging, allowing the creation of databases that could be used for the quantitative assessment of patients
(Zankl et al. 2002 ; Douglas et al. 2003 ; White et al. 2004 ; Mori et al. 2005 ; Dellavia et al. 2008 ; Maal
et al. 2008 ; Sawyer et al. 2009 ; Sforza et al. 2009 ) .
Clinicians working with the head and face (maxillo-facial, plastic, and esthetic surgeons; and
orthodontists and prosthodontists) are those mostly interested in this three-dimensional information
(Zankl et al. 2002 ; Ferrario et al. 2003 ; Hajeer et al. 2004 ; Sforza et al. 2007 ; Dellavia et al. 2008 ;
Maal et al. 2008 ; Sawyer et al. 2009 ; Schwenzer-Zimmerer et al. 2008 ; Ozsoy et al. 2009 ; Plooij
et al. 2009 ) . Indeed, current non-invasive diagnostic methods could reduce the biological burden of
repeated examinations for patient assessment, treatment planning, and evaluation of results. This is
particularly important for those children whose malformations cannot be corrected in a single
episode, but require several surgical, orthopedic, and orthodontic interventions between birth and
Table 32.3 Set of 50 facial landmarks currently digitized with contact instruments.
The landmarks are shown in Fig.
32.3
Midline Paired
Forehead tr Trichion ✓
g Glabella ✓
Eyes ex Exocanthion ✓
en Endocanthion ✓
os Orbitale superius ✓
or Orbitale ✓
Nose n Nasion ✓
prn Pronasale ✓
c ¢ Columella ✓
sn Subnasale ✓
al Alare ✓
ac Nasal alar crest ✓
itn Inferior point of the nostril axis ✓
stn Superior point of the nostril axis ✓
Mouth and lips ls Labiale superius ✓
sto Stomion ✓
li Labiale inferius ✓
sl Sublabiale ✓
chp Crista philtri ✓
ch Cheilion ✓
Chin pg Pogonion ✓
me Menton ✓
Lateral part of the face ft Frontotemporale ✓
chk Cheek ✓
zy Zygion ✓
go Gonion ✓
Ears t Tragion ✓
pra Preaurale ✓
sa Superaurale ✓
pa Postaurale ✓
sba Subaurale ✓
The set of 50 landmarks currently used in our laboratory is listed
622 C. Sforza et al.
adult life (White et al. 2004 ; Dellavia et al. 2008 ; Schwenzer-Zimmerer et al. 2008 ; Plooij et al.
2009 ) . Also, the use of a piece of three-dimensional information that considers both the underlying
skeletal structure and the overlying soft-tissue cover is valuable in the global assessment of the
patient (Maal et al. 2008 ; Plooij et al. 2009 ) .
The three-dimensional digitization of craniofacial characteristics is also widely used for the man-
ufacturing of individualized ortheses, prostheses, and safety headgears: the imaged part of the body
is used as a CAD (computer-aided design) source, and via CAM (computer aided machinery) tech-
nology, the artifi cial manufact is produced, with a reduction in time, costs, and patient discomfort.
Along with these classical fi elds, internal medicine that deals with general diseases is currently
investigating possible associations between variations in facial morphology and body disorders: the
search for low cost, fast, and non-invasive markers of more complex diseases has been particularly
important in the metabolic fi eld. Rapid screening, standardization of functional examinations, pro-
gression of disease, and quantifi cation of side effects can all benefi t from specifi c markers that can be
longitudinally repeated with minimal discomfort to the patient, and a reduced monetary cost. In par-
ticular, applications in uremic patients on chronic dialysis, in patients with undiagnosed celiac disease,
in obese adolescents, and in HIV-infected patients, have been proposed (Sforza and Ferrario 2006 ) .
Hypotheses about the relationships between facial shape and asymmetry, and aspects of cognition
that involve the anterior brain, are currently tested with investigations on three-dimensional facial
morphology. Indeed, during early fetal life, there is a strict relationship between face and anterior
brain: the localization of facial alterations, together with the known timing of their embryological
development, may offer more insights into brain development and its alterations (Shaner et al. 2000 ;
Hennessy et al. 2006 ; Sforza and Ferrario 2006 ) .
Three-dimensional assessments of facial morphology are also used for low-cost screening of
neurodevelopmental alterations such as the fetal alcohol syndrome that involve characteristics facial
alterations. Borderline patients or gene carriers could also be screened using quantitative tools
assessing selected facial features (Douglas et al. 2003 ; Fang et al. 2008 ) . The development of cost-
effective methods for fi eld screening seems particularly important in low-income countries and
areas, where the patients cannot be offered all the opportunities which are available in more devel-
oped parts of the world (Douglas et al. 2003 ) .
Together with the direct assessment of the living, digital facial morphology is currently success-
fully applied into several forensic fi elds (DeAngelis et al. 2009 ) : for instance, all techniques for
facial reconstruction from skeletal remnants need three-dimensional sex-, age-, and ethnic-based
normal databases that should be renewed considering the secular trends in body dimensions. Three-
dimensional data are also necessary to artifi cially “age” facial images of kidnapped children, as well
as to give an age to victims of pornography and pedopornography.
Forensic, commercial, and security identifi cation of persons is increasingly using virtual images,
and three-dimensional digital images should be used instead of conventional anthropometry
(DeAngelis et al. 2009 ) to determine the identity of probands.
Virtual applications are also usefully employed in computerized simulations for the entertainment
arena: television, cinema, virtual reality, and computer games all use digital three-dimensional
sources obtained non-invasively from both humans and animals.
32.6 Conclusions
In conclusion, digital, computerized, non-invasive instruments for three-dimensional facial anthro-
pometry appear to offer new possibilities for both basic investigators and clinicians. Detailed quan-
titative (and often also qualitative) information about the facial soft tissues of a given patient may
62332 Three-Dimensional Facial Morphometry: From Anthropometry to Digital Morphology
allow a better and faster diagnosis, especially when the relevant reference values (selected for age,
sex, and ethnic origin) are available.
Maxillo-facial, plastic, and esthetic surgery, as well as orthodontics and dental prostheses, may
usefully apply this information.
Computerized tools may also permit to simulate treatment, and to provide an approximate idea of
the fi nal outcome, thus facilitating the process of informed consent. Longitudinal assessments can
offer a quantitative evaluation of the post-treatment results, with concomitant evaluations of the pos-
sible relapse.
At the same time, the same clinical reasoning used for conventional anthropometry can be used,
via the maintenance of landmark-based measurements.
Summary Points and Practical Methods
A global, three-dimensional, quantitative assessment of the craniofacial characteristics may help •
in clinical diagnosis.
Together with conventional radiographic analyses of the skeleton, the soft-tissue structures should •
also be analyzed to provide a complete evaluation of any patient, and should be compared to those
of healthy subjects of the same age, sex, race, and ethnic group.
Both contact and optical computerized instruments can be used for the three-dimensional analysis •
of facial soft tissues.
Contact instruments allow the assessment of selected facial landmarks with a reduced monetary price. •
Optical instruments allow a detailed record of all facial surfaces, but they are more expensive. •
Three-dimensional virtual facial reconstructions are currently used in several medical, forensic, •
and industrial fi elds.
Acknowledgments We are deeply indebted to all the subjects who served as volunteers in our laboratory. The pre-
cious work of staff and students, who helped in data collection and analysis, is also gratefully acknowledged.
References
Aldridge K, Boyadjiev SA, Capone GT, DeLeon VB, Richtsmeier JT. Precision and error of three-dimensional pheno-
typic measures acquired from 3dMD photogrammetric images. Am J Med Genet. 2005;138A:247–53.
DeAngelis D, Sala R, Cantatore A, Grandi M, Cattaneo C. A new computer-assisted technique to aid personal identi-
fi cation. Int J Legal Med. 2009;123:351–6.
Dellavia C, Catti F, Sforza C, Grandi G, Ferrario VF. Noninvasive longitudinal assessment of facial growth in children
and adolescents with Hypohidrotic Ectodermal Dysplasia. Eur J Oral Sci. 2008;116:305–11.
Douglas TS, Martinez F, Meintjes EM, Vaughan CL, Viljoen DL. Eye feature extraction for diagnosing the facial
phenotype associated with fetal alcohol syndrome. Med Biol Eng Comput. 2003;41:101–6.
Fang S, McLaughlin J, Fang J, Huang J, Autti-Ramo I, Fagerlund A, Jacobson SW, Robinson LK, Hoyme HE,
Mattson SN, Riley E, Zhou F, Ward R, Moore ES, Foroud T, Collaborative Initiative on Fetal Alcohol Spectrum
Disorders. Automated diagnosis of fetal alcohol syndrome using 3D facial image analysis. Orthod Craniofac Res.
2008;11:162–71.
Farkas LG. Anthropometry of the head and face. 2nd ed. New York: Raven Press; 1994.
Farkas LG, Katic MJ, Forrest CR, Alt KW, Bagic I, Baltadjiev G, Cuhìnha E, Cvicelova M, Davies S, Erasmus I,
Gillet-Netting R, Hajnis K, Kemkes-Grottenthaler A, Khomyakova I, Kumi A, Kgamphe JS, Kayo-daigo N, Le T,
Malinowski A, Negasheva M, Manolis S, Ogeturk M, Parvizead R, Rosing F, Sahu P, Sforza C, Sivkov S,
Sultanova N, Tomazo-Ravnik T, Toth G, Uzun A, Yahia E. International anthropometric study of facial morphol-
ogy in various ethnic groups/ races. J Craniofac Surg. 2005;126:615–46.
Ferrario VF, Sforza C, Poggio CE, Cova M, Tartaglia G. Preliminary evaluation of an electromagnetic three-
dimensional digitizer in facial anthropometry. Cleft Palate-Craniofac J. 1998;35:9–15.
624 C. Sforza et al.
Ferrario VF, Sforza C, Serrao G, Ciusa V, Dellavia C. Growth and aging of facial soft tissues: A computerized
three-dimensional mesh diagram analysis. Clin Anat. 2003;16:420–33.
Ghoddousi H, Edler R, Haers P, Wertheim D, Greenhill D. Comparison of three methods of facial measurement.
Int J Oral Maxillofac Surg. 2007;36:250–8.
Hajeer MY, Ayoub AF, Millett DT. Three-dimensional assessment of facial soft-tissue asymmetry before and after
orthognathic surgery. Br J Oral Maxillofac Surg. 2004;42:396–404.
Hammond P, Hutton TJ, Allanson JE, Campbell LE, Hennekam RC, Holden S, Patton MA, Shaw A, Temple IK,
Trotter M, Murphy KC, Winter RM. 3D analysis of facial morphology. Am J Med Genet. 2004;126A:339–48.
Hennessy RJ, McLearie S, Kinsella A, Waddington JL. Facial shape and asymmetry by three-dimensional laser sur-
face scanning covary with cognition in a sexually dimorphic manner. J Neuropsychiatry Clin Neurosci.
2006;18:73–80.
Maal TJ, Plooij JM, Rangel FA, Mollemans W, Schutyser FA, Bergé SJ. The accuracy of matching three-dimensional
photographs with skin surfaces derived from cone-beam computed tomography. Int J Oral Maxillofac Surg.
2008;37:641–6.
Majid Z, Chong CA, Ahmad A, Setan H, Setan H, Samsudin AR. Photogrammetry and 3D laser scanning as spatial
data capture techniques for a national craniofacial database. Photogramm Rec. 2005;20:48–68.
Mori A, Nakajima T, Kaneko T, Sakuma H, Aoki Y. Analysis of 109 Japanese children’s lip and nose shapes using
3-dimensional digitizer. Br J Plast Surg. 2005;58:318–29.
Ozsoy U, Demirel BM, Yildirim FB, Tosun O, Sarikcioglu L. Method selection in craniofacial measurements:
Advantages and disadvantages of 3D digitization method. J Craniomaxillofac Surg. 2009;37:285–90.
Plooij JM, Swennen GR, Rangel FA, Maal TJJ, Schutyser FAC, Bronkhorst EM, Kuijpers-Jagtman AM, Bergé SJ.
Evaluation of reproducibility and reliability of 3D soft tissue analysis using 3D stereophotogrammetry. Int J Oral
Maxillofac Surg. 2009;38:267–73.
Sawyer AR, See M, Nduka C. 3D stereophotogrammetry quantitative lip analysis. Aesthetic Plast Surg. 2009;33:
497–504.
Schwenzer-Zimmerer K, Chaitidis D, Berg-Boerner I, Krol Z, Kovacs L, Schwenzer NF, Zimmerer S, Holberg C,
Zeilhofer HF. Quantitative 3D soft tissue analysis of symmetry prior to and after unilateral cleft lip repair compared
with non-cleft persons (performed in Cambodia). J Craniomaxillofac Surg. 2008;36:431–8.
Sforza C, Ferrario VF. Soft-tissue facial anthropometry in three dimensions: from anatomical landmarks to digital
morphology in research, clinics and forensic anthropology. J Anthropol Sci. 2006;84:97–124.
Sforza C, Peretta R, Grandi G, Ferronato G, Ferrario VF. Three-dimensional facial morphometry in skeletal Class III
patients. A non-invasive study of soft-tissue changes before and after orthognathic surgery. Br J Oral Maxillofac
Surg. 2007;45:138–44.
Sforza C, Grandi G, Catti F, Tommasi DG, Ugolini A, Ferrario VF. Age- and sex- related changes in the soft tissues of
the orbital region. Forensic Sci Int. 2009;185:115.e1–115.e8.
Shaner DJ, Peterson AE, Beattie OB, Bamforth JS. Assessment of soft tissue facial asymmetry in medically normal
and syndrome-affected individuals by analysis of landmarks and measurements. Am J Med Genet.
2000;93:143–54.
Weinberg SM, Scott NM, Neiswanger K, Brandon CA, Marazita ML. Digital three-dimensional photogrammetry:
evaluation of anthropometric precision and accuracy using a Genex 3D camera system. Cleft Palate-Craniofac J.
2004;41:507–18.
Weinberg SM, Naidoo S, Govier DP, Martin RA, Kane AA, Marazita ML. Anthropometric precision and accuracy of
digital three-dimensional photogrammetry: comparing the Genex and 3dMD imaging systems with one another
and with direct anthropometry. J Craniofac Surg. 2006;17:477–83.
White JE, Ayoub AF, Hosey MT, Bock M, Bowman A, Bowman J, Siebert JP, Ray A. Three-dimensional facial char-
acteristics of caucasian infants without cleft and correlation with body measurements. Cleft Palate-Craniofac J.
2004;41:593–602.
Wong JY, Oh AK, Ohta E, Hunt AT, Rogers GF, Mulliken JB, Deutsch CK. Validity and reliability of craniofacial
anthropometric measurement of 3D digital photogrammetric images. Cleft Palate-Craniofac J. 2008;45:232–9.
Yamada T, Mori Y, Minami K, Mishima K, Tsukamoto Y. Three-dimensional analysis of facial morphology in normal
Japanese children as control data for cleft surgery. Cleft Palate-Craniofac J. 2002;39:517–26.
Zankl A, Eberle L, Molinari L, Schinzel A. Growth charts for nose length, nasal protrusion, and philtrum length from
birth to 97 years. Am J Med Genet. 2002;111:388–91.
