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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