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7巻2号(1997) 59
原 著
A NEW ONTOGENETIC APPROACH TO
CRANIOFACIAL GROWTH
THE BASIS OF PROJET TELECRANE INTERNATIONAL
Marie-Josephe DESHAYES
Summary
The biometry using statistics on a sample of 185 children suffering from malocclusions,
examines the flexion of the basicranium. The organisation of the malocclusions seems
characterized by a complex order, which functions according to a systemic logic: the cranio-
facial contraction. Biodynamic process occurs from the embryonnic period; dento-facial
dysharmonies are a result of chaotic attractors upon biodynamic process.
Key Words: Cranio-facial architecture. Biodynamic. Ontogenic development. Hominiza-tion.
Introduction
Dentofacial orthopaedics, or orthodontics,
joins the medical and social sciences as a newexploration of the human being. In terms of
exploration, cephalometry has the place of
honour. Will cephalometry resolve the fun-
damental problem: will we now be able to
predict growth? To respond affirmatively tothis question would be an ambitious project
on our part. Our intention is different. In
fact, we shall set this question aside, for the
moment has not yet arrived for us to be able
to read all genetic and hormonal information
in the child and predict the growth to come.
We are proposing a new exploration of the
craniofacial skeleton, one done within an
ontogenetic perspective, by attempting to
understand the developmental modes that
lead the system in the trajectory where it
grows; in short, we hope to know andunderstand the system's growth "dynamics."
I Cephalometry: Diagnostic Tool in Ques-
tion
We are experiencing more and more
childhood dental malalignments. The treat-
ment of these malalignments is now a point of
debate amongst those who adhere to early
treatment and those who espouse delayed
treatment.
Delayed treatments, classically the most
widespread, are performed on an already
constituted and known facial scheme; in
comparison, early treatments, applied to the
temporary teeth, correct deformities that we
suppose to be, from the beginning, potential-
ly generative anomalies in the permanent
teeth. In reality, the debate concerns the
diagnostic and prognostic order since all of
the causes are not known. Predictions of
growth are, in fact, very difficult in the lacteal
period because dental malalignments are lessspectacular and, in this context, the facial
growth to come is largely considered un-Child Stomatology-18, rue Pasteur 14000 CAEN
60 M.-J. Deshayes 7巻2号(1997)
known.
Cephalometry developed, as a diagnostic
aid, and enjoyed a blossoming period, but it
has lost its pre-eminence according to J.
Phillipe (19). A large number of orthodon-
tists no longer accept the use of cepha-
lometric analyses based on adult statistics (on
permanent dentition). They are, in ouropinion, unsuitable for the study and explora-
tion of early childhood.
Already in 1978, sensing a lack of informa-
tion in the use of strictly dentofacial analyses,
Jean Delaire put forth a new architectural
analysis (9). It was an important step, since
his analysis connected facial harmony with
cranial harmony (figure 1). The only other
equivalent at that time was the analyses of
Gudin and Leroi Gourhan. His analysis
consisted of a compilation of a large number
of landmarks and lines already used by other
authors (Bimler, Bjork, Chateau, Enlow,
Ricketts, Sassouni, Wendelwylie) . These
other authors felt it necessary to understand
facial architecture in its neurocranial context.
Delaire's contribution of architectural analy-
sis was important for defining the conditions
Fig. 1. The average cranial profile detemined by the mathematical construction
on a sample of 185 children represents more or less the ideal architectural
profile that Jean Delaire described.
7Šª2 •† (1997) A New Ontogenetic Approach to Craniofacial Growth 61
of cranial equilibrium of the maxillary and themandible; but the analysis does not explainthe relationships between the cranium andthe face during development. What is more,the absence of cranio-facial correlations is aclassic argument (2). It would be desirable,however, to distinguish the absence ofstatistical correlations between adult craniaand the absence of craniofacial correlationsduring ontogenesis. However, the lack ofcorrelation with final adult products does notnecessarily signify that correlations betweenthe development of the cranium and the facenever existed.
Moreover, the cranium is not approachedas a system in permanent modificationevolved from the embryonic period. Theseanalyses do not recognize the ontogeneticheritage; the ontogenic trajectory or theentire ontogenetic identity of the patient ismissing. It is necessary to understand what wemean by trajectory; the cranium of an infantdoes not have the same equilibrium of that ofan adult. We must reason in terms ofontogenetic cephalometry, which is to say, wemust introduce the notion of changing statesduring growth, and thus integrate the notionof time into the trajectory.
II Ideal Architecture: A Reductionist Princi-
pleWhen we adopt the postulate of the
existence of an architectural system with astable and ideal trajectory there is confusionbetween the concept of harmony and theaverage situation. Cephalometric standardsand the concept of normality that could besummed up as belonging to a statisticalaverage (17) are not necessarily the objec-tives to be obtained. First this is due to the
lack of pertinence for replacing the disrup-
tive, skeletal element within an individual
trajectory (without searching to compare it to
a population average).
There is nothing, surprising about the large
number of automated analyses that permit
practitioners to use their discretion when itdoes not seem justifiable to refer to a norm or
an idealized situation. In fact, we believe that
a statistical problem in the use of these"norms" exists: a large number of computer
generated analyses of data study the "maintendency" and determine a "résumé", a
median that erases biological diversity (E.
Terrouane, "Plaidoyer pour une statistique
ingenue", 14th meeting of the Societe Fran-
caise de Biologie Theorique. 1994). Workingwith these norms, a conceptual problem is
liable to ensue: the pursuit of an ideal
trajectory of growth and the neglect of
individual variations that stray from the
medians. As a result, the objective of an ideal
trajectory is reductionist and the concept of
normality which is based on a populational
average must be put into question.
On the other hand, the concept of 'stabil-
ity' arises out of post-therapeutic recurrence;
after an orthodontic treatment, the risk of
seeing a recurrence is explained by the fact
that nature can reassert itself. Do we
conclude that, in matters of growth predic-
tion, we will remain totally unsuccessful and
that it will remain impossible to predict the
reactions of the craniofacial system?
On the whole, must we continue with the
logic of an unpredictable functioning where
dental malalignments are the consequence of
a disorganization of the craniofacial system
whose adjustment is unforeseen? This post-
ulate is not satisfactory.
62 M.-J. Deshayes 7Šª2 •† (1997)
Fig. 2.
5 years old, before treatment. after 6 months with orthopedic forces.
at 13 years old (without any treatment between 6 and 13).
7Šª2•†1997) A New Ontogenetic Approach to Craniofacial Growth 63
We prefer to ask if it is possible to establish
a range of reversibility within the trajectory in
which we are intervening. Happily, successful
treatments exist without recurrences that
permit the craniofacial system to resume aharmonious trajectory, but it is impossible to
know if this trajectory is close to that which
would have been the skeleton's trajectory if it
had not been destabilized. In fact, compara-
tive studies, before and after treatment, tend
to show that at the end of a successful
orthodontic treatment, the new architectural
equilibrium does not systematically follow the
foreseen ideal; new metric and angular
relations exist that can be far from this
foreseen ideal (figure 2). In our opinion, the
fact that after treatment, a harmonious
trajectory exists that is not necessarily based
on an architectural ideal proves:
1) that there is no reproductibility of the
ideal model; but no reproductibility dones
not mean irreversibility;
2) that the internal processes of development
are not chaotic since it is possible to find a
range of reversibility with the activation of
the memory of harmonious attractors and
that craniofacial harmony is born of a family
of new attractors.
Numerous authors have already noted that
certain malocclusions belong to notably
different morphologies (14) Bjork, Costa and
Sassouni mention cranio-facial relations as do
Brodie, Cousin, Kokich, and Solow; on the
other hand, Baumrid does not find a correla-
tion between the amplitude of the flexion of
the basicranium and the position of the
mandibular condyle; Knowles even pre-
scribes to inverse evolution. Popovich and
Anderson (1) agree, however, on a certain
relation ship between the flexion of the base
and the position of the mandibular condyle:
the bases flexed very little make up class II
occlusions; but greatly flexed bases develop
into class I occlusions but never class III. On
the other hand, Weidenreich, Enlow and
Lavelle see a tendency towards class III
occlusions in very flexed bases. Therefore on
the whole, dentocraniofacial disequilibria
appear impossible to systematize and facial
behaviours are signs of incoordination be-
tween the maxillary, the mandible and the
basicranial architecture; will this be the loss
or the dissipation of a coordination, or more
simply a strange effect of the cephalometric
analyses used?
We have concentrated our work on the
research of a determining principe of basicra-
nial morphology on the equilibrium of the
face and analyzed the ontogenetic processes
of cranial development in order to better
understand the effects on the face. The
important phenomenon is that all morpholo-
gies establish themselves around a growth
process well known in primates (4): theflexion of the base of the cranium, or occpital
tipping (18-8) (Denicker, 1885; Anthony and
Saban, 1952; Delattre and Fenart, 1960;
Moss, 1982). The big question is whether the
occipital flexion has repercussions on the two
stages of the face.
Fig. 2. =Xray and cephalometrics before treatment: there is a maxilla in a foreward position; the basicranium isextension (the sphenoidal angle is open, 126°8; the occipito-pterygoidian plane is negative-2°; there is a TMG in adistal, posterior position). We notice the line Bregma-Pts-Pti at 188°.
Cephalometrics show that the new equilibrium between the maxilla and the mandible does not superpose with an idealbasicranium =the basis is still in extension, but the line Bregma-PTs-PTi as changed (179°).
64 M.-J. Deshayes 7Šª2•†(1997)
Param
Fig. 3. The sample of 141 patients classified by molar malocculusion and cranial specificies (CS).
7Šª2•†(1997) A New Ontogenetic Approach to Craniofacial Growth 65
PARAM
Fig. 4. The sample of 47 infants <M1
III Establishing our Method of Exploring the
Cranio-facial Architecture with the Com-
puter Program Cranexplo.1 METHODS
In our study, we compare the equilibrium
to a binary system: each mobile bone is no
longer compared to a norm nor to an ideal
equilibrium line, but is integrated in what
those who study dynamics call "bassins of
attraction." We have, of course, used aver-
ages with the linear analysis principle of data,
but we have also taken eccentric morpholo-
gical variations into consideration with re-
gards to medians. Eventually we are looking
to make a model of the attractive fields where
the craniofacial architectures oscillate; our
goal will be to find whether facial dysmorph-oses find their origin in random facial
phenomenon, or if they are the object ofinternal modes of growth in the cranium.
Our sample consisted of:
1) a series of 141 patients between second
infacny (after six years old) and the end of
puberty: 28 class I; 42 class II; 35 BB "bout about" (the first up and down molars have
their mesial point on the same vertical line, in
mixed dentition); and 36 class III: (figure 3).
66 M.-J. Deshayes 7Šª2•†(1997)
Fig. 5. The cranio-facial biometry with Cranexplo".
2) a series of 47 children having no more
than their first permanent molar "<M1" and
their temporary teeth, children approximate-
ly six years old (figure 4).
2 MEASUREMENTS:
We have, first of all, analyzed the flexion of
the basicranium (or the average ontogenetic
stage of flexion).
We began in 1992, with the help of our
computer software CRANEXPLO, setting
up a database of 27 selected points of the
cranium and face, in order to provide
information on the cranial contraction (in
amplitude and in architecture).
This first step of cranial, analysis is
essential as it permits an understanding and
knowledge of the angularities of the basicra-
nium and/or the proportions of the basicra-
nial foundations in the facial skeleton. We
selected four organizational planes (figure 5).
plane A spheno-ethmoido-frontal or the an-terior and superior part of the basicranium
(essentially following the sphenoidal andethmoidal planes, from the anterior clinoidal
apophyses to the naso-fronto-maxillary
joint).
plane B spheno-occipital or the endocranialslope of the occipital clivus and of the
basisphenoid.
plane C occipito-pterygoidian or the linefrom the pterygoide apophyse (PTi), and
tangent to the lowest part of the occipital
scale (OB): this incorporates the level of the
occipital scale and the orientation of the
pterygoide apophyse, compared to the para-llel of plane A (figure 6).
plane D or base line, with its two segments,
7Šª2•†(1997) A New Ontogenetic Approach to Craniofacial Growth 67
Fig. 6. The plane C cranio-pterygoidian is compared to the parallel of the plane A.
the declivity is negative with a high level of OB
the declivity is positive with a low level of OB
facial and spinal (rachidian) respectively,
from the M point to the condylar point of the
temporal bone (CT). It extends to right back
to the right of the tangent at the posterior
part of the occipital scale (Occ) and forwards
just right of the tangent with the anteriorfrontal part (F).
After the location of these four planes on a
telecranium profile, we measured four para-
meters:
1) the angularity between planes A and
B =sphenoidal angle =parameter 1
2) the angularity between planes A and
D= anterior angle of the
basicranium=parameter 2
3) the angularity between plane C and the
parallel in plane A=parameter 3
4) the proportions in plane D, of the facial
field and the spinal field=parameter 4.
We have studied the correlation between
each parameter and reported six statistical
series of which we will study the baricentres .
We have entrusted the entirety of our
results to ,the Society of Human Biometry of
Paris (la Societe de Biometrie) (12-15).
VI Characteristics of the Basicranial Flexion
1•‹Average values of the occipital descent: the
declivity of the occipito-pterigoidian plane ,
compared to the plane A spheno-ethmoidal:
general average= +0°17 (approximatively pa-
rallel to plane A)
malocclusion of class III type: +2°33
malocclusion of class II type: °1°33
malocclusion of class I type: °1°78
malocclusion of class BB type: +0°5
infants<M1=3°56 (the declivity is
strongly positive with a low occipital).
We notice that among the 47 infants<M1,
only 7 have a OB-PTI value inferior to a
+0°17; 85%, therefore, have an occipital
tipping strongly positive, regardless of the
molar occlusion encountered; after the age of
6 years, only 43% have OB-PTi> +0°17.
2°Average values of the sphenoidal angle:
between plane A spheno-ethmoidal and
plane B spheno-occipital: Plane A/Plane B
general average =117°36malocclusions of class III type: 114°28
malocclusions of class II type: 120°21
malocclusions of class I type: 117°82
malocclusions of class BB type: 116°72
-infants<M1= 115°43
3°average values of the temporal verticaliza-
tion:
the angle between plane A sheno-ethmoidal
and the plane of the temporal basi-cranium
D, passing by the naso-fronto-maxillary joint
(M) and the temporal condyle (Ct): PlaneA/Plane D general average = 20°94
malocclusions of class III type: 21°63
malocclusions of class II type: 20°01
malocclusions of class I type: 21°37
malocclusions of class BB type: 21°02
68 M.-J. Deshayes 7Šª2•†(1997)
-infants<MI= 20°49
4°average values of the frontalization of the
temporal petrous pyramid, or the sagittal
position of the temporomandibular joint ac-cording to the projection plane of base F-Occ
(plane D elongated forward as far as thefrontal projection): F-Ct in percentage of F-
Occ general average = 51%
malocclusions of class III type: 50%
malocclusions of class II type: 51%
malocclusions of class I type: 51%
malocclusions of class BB type: 50%
-infants<MI=50%
Discussion
With these results in mind, it is tempting to
rush to conclude that
-the very flexed bases have preferentially
anteriorised and descended condyles, a
closed sphenoidal angle, an occipital equilib-
rium in a positive and lowered position. They
have a tendency to class III type malocclu-
sions
-the slightly flexed bases have, preferential-
ly, retreating condyles, in a high position, an
open sphenoidal angle, and a high, negative
occipital position, with a tendency to class II
malocclusions. Paradoxically, however, when
we analyze the coefficients of correlation
between the 4 cranial parameters, but, save
the dependence (R=0.78) between the
occipito-pterygoidian equilibrium and the
sphenoidal angle, we do not see any specifici-
ties (figure 7). This signifies a statistical order
problem: the variations in regards to the
average profile can not be systematized.
V Modelization of Cranio Facial Dvasharmo-
nies and Discordances
1•‹Methods
We will take into account all the modes of
distribution (medians and eccentrics) of the
cranial parameters of the 141 patients.
2°Results
Certain relationships are associated in a
preferential manner and we see 2 invariants
of distribution appear or 2 general modes of
growth trajectories. The cranial specificities
establish themselves from 2 big bassins of
attraction.
We give the qualification E "Extension" or
C "Flexion-Contraction" on either side of the
averages. These cranial specificites (noted
"CS" in the tables figures 3) are:
Parameters in Extension "E":
A/D <20°94 - OB-PTi< + 0°17
Fig. 7. Correlation analysis between the four cranial
parameters:parameter 3 (Occipital)=0.78-0.60-0.51parameter 1 (A/B)=0.78-0.60-0.36parameter 2 (A/D)=0.60-0.60-0.09parameter 4 (CF)=0.51-0.36-0.09
7Šª2•†(1997) A New Ontogenetic Approach to Craniofacial Growth 69
Fig. 8. The bassin of contraction "C": all the cranial parameters are "C".
- A/B>117°36—Param 4>0,51
Parameters in contraction "C":
A/D>20•K94-OB-PTi>0°17
- A/B<117°36—Param 4<0.51
Let's look at the characteristics of these
dysharmonies that we call "extension" or
"contraction".
a) In the bassin of contraction C: the
architectural tables have relationships that
demonstrate a cranial profile which is more
contracted than the median profile (figures
8-9)
-the occipital tipping is very positive at
+4°92
- the sphenoidal angle is at 110•K52
-the angle plane A plane D is open at 22°73
-the facial field is short at 0°49
This contraction exists in 29 cases, and
engenders mostly class III (17), class BB (6),
some class I (2) but only 4 cases of class II.
This contraction, thus, continues and isamplified after the appearance of M1, and theoccipital tipping surpassed that of thechild<M1 (+4°92/+3°56). But it must benoticed that the sphenoidal angle does notclose in the same proportions but stays at110°52 (more closed than the general averageof 117°36 after M1). The shortening of thefacial field FCt is definite=0.49 (compared to0.51 in general): the mandibular condyles areanteriorized.
On the vertical plane, the tendency is tolengthen the inferior stage of the face with adivision of ENA-Me/U>0.80 (we will see inthese extended EEEE models an inferiorvalue of 0.80. The superior stage of the facedivides between 0.55 and 0.70 of U. Thenoticeable fact is the antero-posterior divisionof the chin. The models CCCC do notnecessarily have a chin in front of the Maxilla
70 M.-J. Deshayes 7Šª2•†(1997)
Fig. 9. A sample of contraction.U=basicranial unit of measurement for resolving
problem of alometry.Max=the maxillary unit (from M to Np) is drawn by aline= if the chin Me is localisated on this line. Me=0:behind this line. Me<0: in front of this line. Me>0.
Fig. 12. The distribution of malocclusions with their
cranial specificities.
Fig. 14. A sample of class I with a cranial mosaic (thereis two parameters "C" and two parameters "E").
Fig. 11. A sample of extension.
Fig. 13. evolution of the cranial architecture. To the
cranial parameters "C" and "E" we add the colour of
the malocclusion green=class III
red = class II
blue=class I
We notice also in "orange" the tendency to lengthen
the inferior stage of the face in class II.
Me>0). But we find the ensemble of 17 case
III's divided with Me>0 or near 0. It is thus
not the reflection of the bassin in extension
where all the chins are set back from the
maxilla, Me<0.
The fact of observing some chins>0 or <0
explains the differences of opinion between
Anderson, Popovich, Weidenreich, and En-
low: for Weidenreich and Enlow, there is a
tendency towards class III. But for Anderson,
7巻2号(1997) A New Ontogenetic Approach to Craniofacial Growth 71
Fig. 10. The bassin of extension "E": all the cranial parameters are "E".
thebasesgreatlymodifiedby flexionarenot
necessarilyinclass III.Intotalthetendancy
tothecranialbassintobeincontractionhasa
form of《facial fiexion》.
b) In the extension field E: the architectural
tables are less contracted than the median
profile (figures 10-11).
The cranial contraction seems to stop and
become inverse with a negative incline on the
occipito-pterygoidian plane at -3•K32. The
sphenoidal angle was very open, 122°45
(compared with the general average 117°36).
In the 31 cases, the majority were class II
(16), some were in class I (8) and BB (7), with
a chin set back from Me<O. The elongation
of the facial field (F-Ct 0.53), i.e., the retreat
of the mandibular condyle, appears to follow
a higher situation (anterior angle plane A
plane D=19•K02). On the vertical plane, the
large receding chins (Me<-13) accompany a
tendency towards a vertical excess of the
inferior stage of the face, but the
situations -7<Me<-2 have instead a re-
lationship ENA-Me/U between 0.66 and
0.80, values close to those of the child<M1 at
the least verticality. In total, the tendency to
the cranial bassin in Extension makes a state
of "cranial facial extension".
c) Discussion
In the evolving dysharmonies towards
flexion and extension, the specificities are
very marked; they reinforce the idea that the
very flexed bases converge at class III type
malocclusions and inversely, the bases in
extension evolve towards class II. These
characteristics limit themselves nevertheless
to two "model" populations because even the
other populations mix their cranial specifici-
ties. In fact, if we study the populations from
their malocclusions these things are no longer
72 M.-J. Deshayes 7巻2号(1997)
systematically conformable (figure 12). *if we examine the population in the class II ,
42 patients, there are indeed 16 patients
whose cranial parameters agree with EEEE,
but 26 class II have cranial mosaics where the
flexion "C" and "E" extension parameters are
associated. *if we examine the 36 patients in class III , there are 17 CCCC concordances, but also 19
mosaics with "C" and "E" mixed.
*as to the 28 cases in class I, they are
distributed in 11 mosaics and the 35 BB in 14
mosaics!
All of these architectural mosaics have
discordant trajectories among themselves.
They let us see that they are born of an
assembly of autonomous, structural elements
but they must not mislead the observer.
The conclusion is that these condyles are
not systematically descended or anteriorized,
or inversely, in a high, retreated position. In
effect, in the cranial mosaics the relations are
mixed. In search of an order in their
complexity, we have confided our sample to
Pr. Terrouane (Professor of applied and
computer mathematics). Remembering the
actual limit of our computer means, he has
taken up the classification.
d) Classification of the cranial architecture
incorporate the transversal dimension. But
this vision does permit to address the
architectural drifting between the 2 bassins of
attraction, between the very contracted
crania and the crania in extension.
VI General Discussion
1) Exploration of the facial skeleton must be
done with cranial parameters in order to note
(figure 13)
Terrouane proposes a model of the popula-
tion whose distribution seems not at all
uncertain. The architectural mosaic that we
observe has been coloured with the occlusal
indicators. Firstly, we see the existence of a
paradox between the simplistic image of the occlusion and the complexity of the adjacent,
cranial, constitutional mosaic. Already the
first message appears: dental malocclusions
use limited, diagnostic markers in common
with a large number of architectural combina-
tions. Similar, occlusal slidings can, thus,
belong to different cranial architectures (but
might not have the same therapeutic perspec-
tives).
We discern bridges between the different
combinations, or evolutionary tendencies.
Contrary to what we might have thought
before, the fluctuations within the ontogene-
tic stage of flexion are not random but
orderly. We are aware of a partial vision of
reality as our study sample is not big enough
and our biometric work must, in future,
the ontogenetic identity or the growth
trajectory in which a disruptive element will
occur; in sum, it is important to know the
starting point of growth, or the bassin of
attraction, where the observed system oscil-
lates; without this knowledge we risk post-
ulating wrongly for the existence of uncertain
phenomena. These are, thus, the result of a statistical problem; but it must be noted that
they risk to generate another problem of a
conceptual kind.
If malocclusions are considered to be
bifurcations or deviations due to disturbances
that disorganize the system, and if we apply
the theory of dissipative structure, we bring
to the forefront the disturbance; if the
secondary disequilibrium to this pass a critical
7巻2号(1997) A New Ontogenetic Approach to Craniofacial Growth 73
value, a new "order" appears with a reorga-
nization of the system and a chaotic evolu-
tion, that is to say an unpredictable readjust-
ment. Logically, through this "chaotic" or "deviationist" concept it is im
possible to find an expected order in dental malocclusions . Consecutively, malocclusions may appear
impossible to systematize because no read-
justment is foreseeable. However, our results show that this reasoning is false: we can make
models of these deforming processes. The
chaotic attractors fluctuate orderly in the
cranial field; the primitive architectural "combination" where the disturbance h
as dispersed itself, is more important than the
disturbance.
2) If we judge the bone equilibria with a
statistical average; it requires a reductionist,
explanation of the organization (20) and
wipes out the individual, natural equilibria
which are sometimes very far from the
average architectural profile. Henri Pineau
has already warned against comparing one
state to a statistical average in human
biometry. Today we must take in account an
order in the complexity of dysmorphoses
because this will direct us inescapably to
abandoning norms as referentials. In this new
context, we postulate a "sensibility" of the
craniofacial system which builds itself or
deforms itself. Following the example of Rene
Thom, it would be the architectural system
that would establish "limits" for its field of
fluctuations.
Let's take the example of a traumatic loss
of the superior incisive. Will this disturbance
always create a disequilibrium in the facial
skeleton and especially a mandibular forward
sliding? That depends, in fact, on the
sensibility of the system. If this disturbance
occus in the bassin of attraction in extension
EEEE the risk is minimal, perhaps even no
risk. If this disturbance occurs in the bassin in
contraction CCCC, the risk is maximal. It is,
thus, the sensibility of the system that
determines the statistic of fluctuations. As a
consequence, there exist individual, internal
determinants to recognize, before searching
to apply treatments that are dictated by an
ideal model.
3) We are advancing finally towards the
conceptualization of a biodynamic process
particular to every individual. It would be the
result or sum of several basicranial bone
activities; these activities come together,
according to a specific global logic of flexion
of the basicranium. The trajectories that
develop have specific properties and interac-
tions according to their basicranial flexion. In
an orthodontic perspective, the main concern
is to know if, regardless of the fluctuations,
the global behaviour researched in the
craniofacial system is however destined to a
similar function, namely class I? Class I, in
this case, would be a supreme attractor.
The example of young Bernard A., whose
architectural combination is a CECE mosaic,
demonstrates a natural occlusion in class I
(figure 14).
4) Results of the cranial exploration of the
infantile population <M1.
As 85% of children <M1 have a positive
occipital tipping, regardless of their molar
occlusion, we have studied the architectural
repercussions of this verticalization of the
occipito-pterygoidian (OB-PTi/plan A).
We have a series of 47 children <M1: 24
class III, 19 class II, 4 BB.
The general average of OB-PTi=+3•K56
We have 24 graphs studying the cranio-
74 M.-J. Deshayes 7巻2号(1997)
cranial or the cranio-facial correlations. Here
are our summaries. We can observe that the
cranial contraction dynamic ends at about age
6 with the eruption of the first permanent
molar.
These results urge us to explore the
dentofacial dysharmonies from a very early
age in order to understand the cranial
contraction dynamic which is acquired before
six years of age and to confront the child's
environmental habits (mastication, oro-fa-
cial, respiratory, nutritional functions etc.)
because these, strengthen the facial dynamic
and compete with the original cranial dyna-
mic. The emergence of the 1st permanent
molar, at about the age of 6 years old, is not a
trivial event. Before this emergence the
dynamic of the cranial contraction is active,
and the occipital tipping positive. The
maintenance of this contraction after birth
must, at the same time, recall the fact that
Homo Sapiens find themselves in the most
pronouned stage of contraction in the scale
for all primates (7). After 6 years of age, the
occipital dynamic seems to reverse and only
43% of all subjects examined still have an
occipital tipping greater than the average, but
with a much weaker amplitude. The cessation
of the flexion of the base comforts us with the
idea that the origin of the phenomenon is to
be researched in the development of the brain
(6).
VII Towards a new Approach to Growth
Predictions
Our thoughts and observations lead us to
propose the hypothesis that the appearance
of dentofacial malocclusions and dysmorph-
oses in the 20th century is secondary to the
occurrence of chaotic phenomenon within
certain stages of child development. If dental
malalignments are the consequence of a
disorganization (loss of harmony, acquisition
of a disharmony) their actual multiplication
may be connected to the fact that the
organizing phenomenon of the craniofacial
system never stopped evolving. Thus our
belief that dentofacial dysmorphoses are the
result of an ontogenetic, destabilizing process
that has been evolving for more than 60
million years (16). The dentofacial dysmorph-
oses that we are seeing today are likely due to
the sensitization to destabilization with the
coordination of the structural mosaic that we
are beginning, today, to place on a biometric
plane. How to effect the regulation of this
mechanism is the relevant question for
orthodontists because this knowledge would
permit us to better choose our therapeutic
actions. We have put forth the hypothesis of a
growth dynamic of the cranium; we have
termed it •sthe long way of flexion•t. Our
clinical observations supported this theory in
1986(10).
In a different vein of research, human
paleontology, Anne Dambricourt-Masasse
revealed in 1987, an evolutionary phe-
nomenon present at the embryonic stage; she
has termed it •sthe cranio-facial contraction•t
(3-5)
The cephalometric architectural mosaic
that we notice signifies an autonomy of
growth for each skeletal element of the
cranial base: the temporal, the basioccipital,
the sphenoid, the ethmoid, the frontal; but
the whole situation will be ordered by a
global logic of flexion of the base. The
general statement is that these trajectories
can be placed on an average and common
architectural table, this is even defined by
7巻2号(1997) A New Ontogenetic Approach to Craniofacial Growth 75
statistical averages. We define, with the help
of this average, the ontogenetic stage of
craniofacial flexion that are attained by our
population and which sets Homo sapiens apart.
But it seems insufficient to us, both in
Paleontology as well as in Orthodontia, to be
content and accept an architectural identity
card for Homo Sapiens; we prefer to know
and understand the logic or the series of the
different developmental stages that allow us
to go back to the original plan, of organiza-tion.
In an orthodontic perspective, when we
want to interfere in the growth trajectory of a
child, it is necessary to understand the
dynamic modes that have ended in an
architectural, disequilibriated result (11).
TO SUM UP, we are advancing towards an
approach of predicting growth that recognizes
the ontogenetic phenomenon that we now
consider to be fundamental—the flexion of
the basicranium. To answer our question, "can we predict growth?" it seems reasonable
to us now to respond that it is possible to
recognize a deforming process that is unique
to every individual.
Conclusion
Cephalometry still has a bright future, but
from our point of view, malocclusions should
be examined in a larger frame of reference,
one which includes the cranium as a whole;
without this, we will lack information on the
plan of the cranial organization of our young
patients.
The position today is indicative of a
biometric reality. The architectural equilib-
rium of the cranium and the face are
connected and ordered around an important
ontogenetic phenomenon of flexion of the
basicranium. The process has numerous
evolutionary trajectories. The architectural
mosaic that we begin to see shows that these
individual trajectories have their own prop-
erties and interactions, and, are ordered.
Successful orthodontic treatments that are
without recurrence demonstrate that the
internal processes of development are not
systematically chaotic since it is possible to
find a range of reversibility there. The
disequilibriated cranial growth is readjustable
thanks to its dynamic capacities.
If orthodontists take the risk of interfering
in the ontogenetic process of development,
they should be, from the beginning, aware of
the internal, individual determinants or the
craniofacial biodynamic of each child before
beginning to apply readjustments. We reveal
finally, the unfinished hominisation phe-
nomenon: dentofacial dysmorphoses are the
result of destabilisations in the assembly of
this mosaic. Architectural equilibrium is
evolving. Orthodontists are privileged obser-
vers of the unfinished hominisation phe-
nomenon. We should, above all, explore the
process more. It is from this perspective of exploration that the Projet Telecrane Interna-
tional (13) was born: compare the growth
dynamics to the general processes of homi-
nisation, by integrating the individual history
of each system examined in the phylum of
contemporary humanity.
日本語要約
頭蓋 ・顔面への新たなる個体発生学的研究―
国際テレビ受像画プロジェクトの基礎
マリー ジョセフ ディザェス
76 M.-J. Deshayes 7巻2号(1997)
まとめ
不正咬合に苦 しんでいる小児185症 例について
統計学を用いる生物測定法によって頭蓋底の屈曲
を調査 した.
不正咬合の成 り立ちは系統的論理;つ まり頭
蓋 ・顔面の歪みに従って働 く複雑な序列によって
特徴づけられているように思われる.
生物学的過程は胎生期から現れ,顎 ・顔面の不
調和は,生 物力学的過程への無秩序な引力の結果
である.(文 責 窪田金次郎)
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