Download Eterophorias importance in pathogenesis of gnatho postural

Eterophorias importance in pathogenesis of gnatho
postural unbalance
Dr. Piero Silvestrini Biavati
MD*, DDS*, PhD**, Master in Posturology***
(* Genoa University, ** Siena University, ***Rome University “La Sapienza”)
[email protected]
Abstract
Posturology is now part of practice dentistry. In this article we enphasize two
different aspects of head and neck posture, probably strictly related: gnathologic
and vision problems. Their alteration can determine a change in body posture. In
gnathology, mandibular sidebending, free-way space alteration, abnormal vertical
dimension and atypical swallowing, all determine head postural adaptations. In
vision science, phorias, strabismus, astigmatisms and eyes motility problems as
well , alter head posture. We believe that changes in head posture induced by
gnathologic problems can modify visus and vice versa.
Key Words
gnathology, posturology, free way space, mandibular sidebending, phorias,
vision, astigmatism, strabismus, ocular motility, ocular wryneck, head, neck
The gnathology he is evolving, concepts off limits only a few years ago, by now
accepted from all the gnathological schools. The fact to mostly consider the
muscles, in the stomatognatic system, we owe it to Bernard Jankelson in the
distant years 50 (9,10). This concept, adverse from the other gnathological
schools that entirely centered the problem on occlusal morphology and condylar
position in the glenoid fossa (centric relationship), strong of its obviousness and
reasonableness, it has unhinged little by little preconceived mechanistic that
appear nowadays obsolete. The fact, by now acquired, that the muscular
determinant is the principal sub-judice, it sets us in front to other olistic questions
type: what does it determine the anomalous muscular activity that brings temporo
mandibular disorders ? (1)
We can word here a long list, simply departing from the most important: the
spatial position of the head, the swallowing, the dysgnathia, the free way space,
the column problems etc. you is able therefore to notice that we can estrange
there from the TMJ district, always finding anatomical functional correlations
(3,11).
The same anatomy is suffering a development by the research of many
anatomists that, they often find new meniscal condyle insertions with other
districts, they discover new muscles and new innervations, that put to hard
probation the simplify mechanistic techniques. Our body is so full of variables
that we are not able to know her of it all and to foresee with safety which is the
origin of the problem of it, in a system so linked that it also prevents us a reliable
statistic analysis (20).
In the postural physiology they are different the way of imbalance. Every
sensorial receptor is potentially able to create troubles in the postural system (4).
We won't enter in this Article on the fine postural system (5), we will only deal
there with the macros postural adaptations. Easily wiew to a careful objective
examination from each of us.
Our body is in continuous adaptation, because of the environmental problems
that time in time succeed.
We will investigate the system of adaptation and oculo-gnatho-postural
imbalance.
To define a gnatho postural imbalance caused by an eteroforia, we must first of
all clarify these terms.
Eterophoria: an imbalance of the visual system, generally a binocular vision
alteration: they are that troubles of the ocular mobility that are maintained latent
from the operation of the cerebral amalgamation; therefore they always admit the
binocular vision and they are defined according to the type of bias, in comparison
to the ortophoric position of the eyes. In practice they are strabismus that are
able to be correct from reflex level.
It results obvious that such problems they induce, or perhaps and better to say
they force, our body to adaptations turns to a compensation, as far as possible,
of the problem caused by the visual system (7).
Gnatho postural syndrome: an interaction between mandibular position and
head and neck posture. With this term we doesn't intend that only the tall bodily
district influences the gnathological system, but simply the strictly correlation.
Other districts can influence the cranio cervical posture, and from this to create
gnathological alterations and vice versa. A gnathological problem doesn't hardly
involve a cranio cervical adaptation. The two adaptations result strictly correlated
(15, 17).
Mandibular adaptations to the head posture.
The muscular system complex depuit to the control of the mandibular position
can be simplified in three subgroups, the elevator muscles, the down muscles
and the nucal muscles, finalized to different functions (Fig. 2). In fact for
mandibular posture we necessarily have to distinguish two different positions:
mandibular rest position and closed bite.
The muscles used for the rest position (rest position, RP) they are mainly the
hyoid muscles. Them, using the hyoid bone as a caruncol, they determine the
position of it, what resultant of the tension of all the muscles to it connected (Fig.
1). As the upperhyoids, as the underhyoids and as the correlated muscles with
clavicle, cervical rachis, pharynx and language actively participate.
The muscles used to intercuspal position (intercuspal position ICP) they are
mainly the elevators, temporalis, masseter, pterygoid etc. (3,9,10,11)
Naturally these are only front muscular chains, they could not work without a
feedback control of the head position with the nucal muscles, in primis
sternocleidomastoids and trapezius. In fact, without their operation, the tension of
the undermandibular muscles would bring the mandible the more in possible
lower part, while contemporarily the uppermandibolars would bring the mandible
in ICP, with the outcome to have a head in maximum flexion in front and
clenching teeth. The nucal muscles proper feed this effect and therefore are
tightly correlated. That's the reason that mandibular posture variations, can
involve variations of the cranial posture. Everything is in sagittal how in frontal
view(Fig. 3).
We can imagine therefore the hyoid
mandibular system as a system to
two-tier caruncola: an extension of
the head will bring to a mandibular
rest
position
more
opened
(mandibular
muscles
more
lengthened), while a bending to a
more closed position (mandibular
muscles more shortened).
In frontal view a bending of the head
to Right, will inevitably cause a
shortness of the mandibular muscles
Fig. 1 spatial relationships among cranio, of the same side, determining a
Right sidebending of the mandible
mandible and hyoid
(Fig.4).
In frontal view, a rotation of the head to Left, it will
drag from the same side, in comparison to a bodily
median line, both mandible and hyoid (even if in
proportionally low measure) but, in comparison to a
median craniomandibular axle, the mandible will
result sidebended to Right. Then with a
gnathological disorder of Right deviation (Fig. 5),
the opposite one of the sidebend of the head.
Fig. 2 Cranio cervical
mandibular hyoid posture
Fig. 3 Ortho posture
Fig. 4 Head flexed to R Fig. 5 Head flexed to L
To notice the move of the ocular visual axis in the three different positions of the
head. Muscles orange: more contracted; pink: more lengthened
Every skew between RP and ICP causes an asymmetrical job of the muscles
and the joints to reach the ICP, potentially becoming iatrogenous in the
problematic neuromuscular pain disfunction and TMJ.
If then the patient has match between RP and ICP
(clench), problem list are subsequently amplified
both to muscular and articular level for the job
overload that these structures are submitted.
The why of this whole examination on the influence
of the posture of the head on the mandible we can
synthesize in a simple postulation: all of this that is
able to influence the posture of the head is able
accordingly to determine gnathological problem
(adaptation).
But the problem can also be seen in opposite way,
Fig. 6 Ocular muscles
producing a second postulation: the mandibular
unbalance (gnathological problem) it is able to influence the posture of the head
and accordingly to determine other accommodation phenomenons.
Here the forias enter in game ….
Every visual defect can induce accommodation phenomenons of the head, to the
functional compensation of the pathology. Such adaptations take the name of
Ocular Wrynecks (OW) (Fig. 7) (6,14,16,18).
From this we can be deduced that visual alterations that produce a OW force the
mandible to suit himself for the new cranial posture. The skew has increased
from the feedback of the hyoid bone and his muscles, that turn to them induce a
further adaptation of the head. Often such compensations are “helped in their
stabilization” from the dental clenching: a way to close a muscular chain and to
allow the mandible to be “near” to the occlusion. The clenching, in a adaptative
circle, will worsen all the gnathological disfunctional parameters. In these cases,
you could be hypothesized that the night bruxism is a mean to allow a
reoxigenation of the elevator muscles stopped all the day in isometric situation.
Fig. 7 Ocular wryneck
The opposite side is possibile also. By my experience I can say that Phorias can
be modify by changing occlusion. The way is always the same: the adaptation. If
the dental occlusion determine a pathological head position, then the visual
system must make an adaptation to this head position, modifing the abitual
ocular axis (Fig. 9, 3, 4, 5).
Fig. 8 Phorias
This determines an asymmetrical
tension of the ocular muscles. Such
imbalance, in a dissociated visual Fig. 9 ocular adaptation to the posture
analysis, with the eyes that cannot of the head
contemporarily sting the same aim,
hands the axis in a not orthogonality situation: the phorias. (Fig. 9)The functional
asymmetries of the ocular muscles (Fig. 6) can induce besides sprains of the
corneal surface: the astigmatism (Fig. 18, 19, 20, 21), in turn possible carrier of
OW.The differential diagnosis is not effortless or easy (2,12,19). Remarkable
experiences are necessary in gnathological, postural and vision fields. Diagnostic
instrumentations are necessary and the strictly collaboration with specialists of
the visual sector: oculists, strabologist, ortottist, comportamental optometrists.
Within the physioterapic treatment, the opposite problem is had, to trace the
occlusal influences and to appreciate its importance (2,4,19). We introduce some
interesting cases, all with correlation between occlusion and visus.
First case: evidence of a phoria with occlusal compensation. To normalization
occlusal test show ocular wryneck and phorias.
Fig. 11
Fig. 10
Balanced
Abitual
bite:
bite: ocular
orthophorias
wryneck with
iperphoria R: R
rotation and
flexion L
Second case: cycloversion normalization (8) after occlusal normalization
Fig. 12
Fig. 13
Abitual
Balanced
bite:
bite:
cyclovers
orthophor
ion Left
ias
eye with
Maddox
cylinders
Third case: normalization of flexion of the head and plantar support that needs the
substitution of the lenses.
Fig. 14 Abitual bite: false
ocular wryneck
Fig. 15 Balanced bite: symmetry of the
posture of the head with reducingastigmatism
Fig. 16 Abitual bite: asymmetry of the
Fig. 17 Balanced bite: symmetry of the
plantar support
plantar support
Fourth case: astigmatism variation after occlusal normalization.
Fig. 18 Right eye: corneal map before and Fig 19 Left eye: corneal map before and
after occlusal balancing.
after occlusal balancing.
Fig. 20
Right eye: To notice the
simulation of the visual sprain to the
ototype and the night-blooming reflexes
before and after normalization
Fig. 21 Left eye: To notice the simulation
of the visual sprain to the ototype and the
night-blooming reflexes before and after
normalization
As is been able to notice can be present important interactions between visual apparatus
and dental occlusion, between dental occlusion and head posture, among head posture
and visual apparatus (2,8). The fine interaction among these districts can induce our
diagnosis in bug invalidating the result of these treatments. We always must consider that
our body is tightly a complexes of correlated compartments either anatomically or
neurologically, with the purpose to be able to make that marvelous function that takes
the name of “adaptation.” The only fact to want to correct a adaptation pathology
necessarily implicates the taking in consideration of the correlated adaptations.
.
Bibliography
1) Andorlini M, La saggezza del corpo, Ed. Castello, Milano
2) Bourdiol R. Occhio e Statica, Ed. C.S.T.N.F. Torino 1994
3) Bousquet L, Le catene muscolari, Ed. Marrapese, Roma, 1996
4) Bricot B, La riprogrammazione posturale globale, Ed. Sauramps, Montpellier
5) Gagey PM, Posturologia, Ed. Marrapese, Roma
6) Gambari M, Silvestrini Biavati P, Diagnosi forie e ipomobilità oculare, Atti Congresso Nazionale
Patologie di confine di Oculistica, Odontoiatria, Neurologia Otorinolaringoiatria, Cenacolo Ligure, Aqui
Terme 5-7 Novembre 2004.
7) Gambari M, Postura e Visione, Atti III Convegno di Posturologia AIFiMM 18-19 Giugno 2005,
Genova.
8) Guidetti G, Marchioni D, Vestibolo e sport, Ed Martina, Bologna
9) Jankelson B, Modern diagnosis and management of musculoskeletal dysfunction of the head and neck,
Mosby Co., 1982
10) Jankelson B, Neuromuscular aspect of occlusion. Effects of occlusal position on the physiology and
dysfunction of the mandibular musculature, Dent. Cl. N.A. 23, 1979
11) Lentini S, Ortodonzia e Postura, Ed. Martina, Bologna
12) Lerman M, A revised view of the dynamics, physiology, and treatment of occlusion: a new paradigm,
Cranio, January 2004
13) Silvestrini Biavati P, "Correlazioni fra postura, occlusione e visus. Approccio diagnostico" Atti del X
Congresso Nazionale A.I.K.E.C.M. Alessandria 15-16-17 Novembre 1997
14) Silvestrini Biavati P, “Postural variations induced by occlusion and visus: correlation with rachis
pathologies” Atti 5° Meeting Ceramics, cells and tissues: Implant for spine. Faenza 1-3 Ottobre 1998 Ed.
IRTEC-CNR, Faenza, Consiglio Nazionale delle Ricerche
15) Silvestrini Biavati P, Lastrico M, " Il trattamento neuromuscolare globale posturale e occlusale nella
sindrome occluso-posturale" Atti XII Congresso Nazionale A.I.K.E.C.M. I Meeting Internazionale
I.C.C.M.O. "Sindrome occluso posturale: ruolo dell'odontoiatria in una patologia multidisciplinare"
Vicenza 10-12 Novembre 2000
16) Silvestrini Biavati P, Gambari M, Correlazioni fra occlusione dentale ed astigmatismo Atti Giornate
Internazionali di Posturologia, Roma, 12-13 Marzo 2005
17) Silvestrini Biavati P, Correlazioni tra occlusione dentale, ATM ed atteggiamenti posturali, Atti III
Convegno di Posturologia AIFiMM 18-19 Giugno 2005, Genova
18) Silvestrini Biavati P, Gambari M, Interazione tra postura mandibolare ed eteroforie, Atti Congresso
Nazionale Patologie di confine di Oculistica, Odontoiatria, Neurologia Otorinolaringoiatria, Cenacolo
Ligure, Aqui Terme 5-7 Novembre 2004.
19) Villeneuve PH, Piede equilibrio e postura, Ed Marrapese, Roma, 1998
20) Voss DE, Ionta MK, Meyers BJ, Facilitazione neuromuscolare propriocettiva, Piccin Ed. Padova,
1991