D0l:10.1051/odfen/2008032 J Dentofacial Anom Orthod 2008;11:232-250 RODF / EDP Sciences

Correlations between orthodontic treatment and posture

Isabelle GAULT

ABSTRACT The tonic postural system controls the equilibrium of posture when the body is completely at rest and when it is moving. It is a complicated mechanism that can call into action a variety of modalities including the assistance of the feet, the skin, the eyes, the masticatory system, the Central Nervous System and the efferent muscles, with all elements working reciprocally. Orthodontists should make a postural assessment before undertaking any treatment. If problems are found they should be dealt with by a multi-disciplinary team. But in every case orthodontists should be aware that their efforts have an effect on posture and can modify the corporal schema of the patient. Orthodontists should pay special attention to patients with scoliosis or any deformity of the spinal column.

KEYWORDS

Posture Tonic postural system Postural treatment Multi-disciplinary treatment Correlation Occlusion-posture Corporal schema Orthodontic treatment.

Address for correspondence: I. GAULT, 1 rue Honore´, d’Estienne d’Orves, 45100 Orle´ans, [email protected] 232

Article available at http://www.jdao-journal.org or http://dx.doi.org/10.1051/odfen/2008032 CORRELATIONS BETWEEN ORTHODONTIC TREATMENT AND POSTURE

1 - INTRODUCTION

Because dental occlusion and gen- sion in with an associated postural eral posture are intimately related, it is deformity without also correcting that always important for orthodontists to postural defect. Recent techniques assess each patient’s over-all posture have encouraged us to place "life-time" and see how any individual malocclu- retainers in order to preserve an sion is incorporated into a possible artificial equilibrium. The relapses that lack of equilibrium. As our specialty often result can be interpreted as a matures, it is advancing from a narrow return to an previous stance that was focus on the oral cavity to an assess- an expression of the patient’s original ment of the patient as a complete postural schema. Postural troubles individual and a postural evaluation is a can, in this way, be at the root of good example of this new approach. It unhappy outcomes in orthodontic makes little sense to treat a malocclu- therapy.

2 – DEFINITIONS

2- 1 – Posture system which sends back instructions that preserve the equilibrium of the Posture is a position of the body, an tonic and tonico-phasic statural mus- attitude that has evovled over the cles. This loop constitutes the indivi- course of phylogenetic evolution. dual’s corporal schema working as a self-maintained cybernetic regulatory system (fig. 1). 2 – 2 – Posturology This is the study of the postural 2 - 3 - 1 - The receptors system and its functioning. These are the elements that receive information from the surround, the exterior receptors, or the body itself, 2 – 3 – The tonic postural system This regulates the equillibrium of the body in space in pure static rest and in movement. It works against gravity and is continually in action when the individual is awake and is directed by the extra pyramidal sys- tem so it is, accordingly, involuntary. The peripheral and central receptors constitute the entry pathway to the tonic postural system. They receive information about the environment Figure 1 and transmit it to the central nervous Schema the basis of the tonic postural system.

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tive because they work reciprocally. The regulatory mechanism intervenes with short and long reflex arcs that regulate the myotatic reflex.

2 - 3 - 2 - At the level of the cerebrum This information is assessed at the level of what Dr Bricot2 has referred to s the central computer, which activates the vestibular nuclei, the basal gang- Figure 2 lions with the central grey nuclei and Receptor: Entryway to the topical postural system. corpus striatum, the cerebellum, the reticular system with the mesencepha- the proprioreceptors. The two princi- lic and red nuclei, and the colliculus. pal receptor sites are the feet and the The associated and commissural for- eyes. The masticatory system can mations have an important role to play interfere with posture as can the in communications between the right entire visceral system. Neither, strictly and left halves of the cerebrum. speaking, can be regarded as postural receptors. The inner ear is an angular and linear accelerometer that is acti- 2 - 3 - 3 - The effectors vated during bodily movement. The postural muscle chains that are A receptor can be a cause of postural aligned in continuous directions and difficulties when, because of some planes to propagate the organizing pathological change, it transmits aber- forces of the body constitute the rant information to the higher nervous effectors. These chains are arranged system. It is acting in an adaptive way in relays between the scapular and the when its deformation results from a pelvic belts. When they are stimulated malfunction of another receptor or from asymmetrically they provoke tilting or a postural problem. This adaptation is a rotations of these protective belts as reversal of normal status in the begin- well as of the spinal column. These ning but it becomes fixed after 10 postural muscles depend on other months. Most of the time involved synergic and antagonistic muscles. receptors are both causative and adap-

3 - PRINCIPAL DEFORMATION OF THE FEET AND THEIR REPERCUSSION ON POSTURE

The feet, which are the is principal the ground. They can be the cause of tonic postural system receptors, are it or reacting in adaptation, that is, they the link between disequilibrium and might become deformed in order to

234 Isabelle Gault. Correlations between orthodontic treatment and posture CORRELATIONS BETWEEN ORTHODONTIC TREATMENT AND POSTURE

Figure 5 2 Figure 3 Pigeon toe: postural consequences, after Bricot . Characterstics of receptors.

with an external tibial rotation, a tendency to a genou varum with added external pressure on the patel- lar clonus. The couple of torsion on the head of the femur and the acetabelum pro- vokes an extension of the ilium and a flexion of the sacrum causing a decrease in the lumbar curve and the flatness of the back. This postural defect is often seen with patients whose mandible is prominent.

Figure 4 Hollow pigeon toe after Bricot2. 3 - 2 - The pes adductus The pes adductus is on the other maintain a maximum of contact with hand one that one that caves in the ground, after pelvic tilting, for internally, astrago-calcanean, with an example, one foot may respond one internal rotation of the tibial and way and the other foot not at all or femoral axes, a tendency to genou differently. They could then be de- valgum with a more internal position scribed as mixed feet. of the patellar clonus. The couple of twisting of the head of the femoral acetabulum causes a 3 - 1 - Club foot forward flexion of the ilium and an extension of the sacrum with a resul- A club foot is one that tilts badly to tant increase in lumbar lordosis and the exterior and forward, associated dorsal cyphosis, or humpback.

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Figure 6 Valgus flat foot after Bricot2.

Figure 7 Flat foot resulting from postural imbalance after Bricot2.

3 - 3 - Asymmetrical feet If the scapular and the pelvic mus- cular belts don’t play their roles Feet are rarely deformed symmetri- properly scoliosis or a tendency to cally. One foot will deviate more than scoliosis may appear. But if they do its mate, or there may be varus on one exert their buffering action, the spinal side and valgus on the other. So feet column remains upright. Toubol and not in harmony contribute to the Perez have demonstrated the adapta- postural disequilibrium. A pelvic tilt tive effect of the masticatory system can exist when legs are of the same experimentally. A slight change in the length. way the feet bear on the ground

236 Isabelle Gault. Correlations between orthodontic treatment and posture CORRELATIONS BETWEEN ORTHODONTIC TREATMENT AND POSTURE

Figure 8 Asymmetrical feet after Bricot2.

modifies mastication. Patients’ seated extra-ocular muscles. The principle axiographic registrations differ from ocular muscular problem is insufficient those made when they are standing. convergence and heterophoria, diffi- culty with parallelism of the visual axes. Hypoconvergence usually af- 3 - 4 - The ocular receptor fects the dominant, or non-directing eye. Defects of convergence and The eye is the second receptor of heterophorias cause a new integration the tonic postural system. It intro- of the corporal schema, disequilibrium duces perception of the exterior of posture with homolateral tilting of through refraction (where problems the shoulder and the pelvis. are often detected and treated in Examiners can easily test ocular children.) and proprioception of the convergence after having stimulated

Figure 9 Cross bites and convergence problems.

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physiological function takes a signifi- cant part in the body’s postural sys- tem. The anterior and posterior muscular changes are biomechanically corre- lated with the muscles of mastication, the super and sub hyoid muscles, the sterno-cleido mastoid, the trapezius, and the pectorals. When disequilibrium affects the tempero- mandibular joint, the tonic postural system decompensates, and when the tonic postural system falls out of equilibrium the TMJ is affected. Thus, patients with a natural Class I occlusion have a posture that is in Figure 10 equilibrium with the scapular planes Consequences of a defect in convergence. and the hips well aligned, the lumbar and cervical curvatures in harmony, the ocular muscles by having the and with the face and the scapular and patient gaze steadily at a mirror handle pelvic belts horizontal. moving laterally and vertically at a But examiners evaluating patients distance of 20 cm and then brought who have Class II malocclusions, in to the base of the nose. The overbites, or a loss of vertical dimen- convergence is considered pathologi- sion will note an advancement of the cal if one eye converges in fits and scapular plane. starts or more slowly than the other or Conversely, when the mandible is if the two eyes stimulated in conver- advanced, the scapula is in a posterior gence part in divergence. position. When the malocclusion of patients who have dental cross bites is cor- rected and they are given a few 3 - 6 - Other factors playing orthoptic exercises good ocular con- vergence is restored. a role in posture If the belts do not produce their Any disturbance of oro-facial func- tampon effect scoliosis or a tendency tion has an effect on posture: to scoliosis develops, but the vertebral – breathing problems; column will remain upright if the belts – tongue position at rest or during exert their tampon effect. deglutition; – problems of mastication (favoring 3 - 5 - The masticatory apparatus one side over the other). Information emanating from the The masticatory apparatus because periodontal membrane, during ortho- of its anatomical location and its dontic treatment, occlusal over-load-

238 Isabelle Gault. Correlations between orthodontic treatment and posture CORRELATIONS BETWEEN ORTHODONTIC TREATMENT AND POSTURE

Figure 11 The masticatory apparatus after Busquet4.

Figure 12 Reciprocal influences, Class I after Bricot3.

Figure 13 Reciprocal influences, Class II after Bricot3.

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Figure 14 Anterior scapula in a patient with a deep bite.

Figure 15 Reciprocal influences, Class III after Bricot3.

ing, sites of infection, from the mus- – the III oculomotor nerve innervat- cles of mastication, in bruxism, per- ing the pupils and the eyelids; haps, or from the TMJ all have – the IV pathetic that serves the repercussions in the postural system, superior oblique muscle of the eye; usually mediated through interference – the VI ocular motor nerve innervat- with the trigeminal nerve. This type of ing the right external muscle of disturbance can affect these nerves:

240 Isabelle Gault. Correlations between orthodontic treatment and posture CORRELATIONS BETWEEN ORTHODONTIC TREATMENT AND POSTURE

Figure 16 Interference with the trigeminal nerve after Meyer7 and Baron.

the eye that, when failing to relax, set off by amalgam and other metals causes faults of ocular convergence; used for restorations in the mouth not – the XI spinal nerve serving the to mention the jewelry worn as pier- neck muscles. cings and cutaneous cervical scarring. We can add that posturologists pay serious attention to the galvanic action

4 - WHAT SHOULD BE DONE IN ORTHODONTIC OFFICES: A SUCCINT POSTURAL ASSESSMENT SHOULD BE INTEGRATED IN THE ORTHODONTIC RECORDS

In order to prepare a postural frontal view as well as postural trou- evaluation of patients correctly, ideally bles in the sagittal plane and point we should ask them to strip to their these out to parents. undergarments. Since some ortho- Examiners can also use a plumb line dontists and many patients may be placed along the hips to evaluate reluctant to do that, the best alter- postural difficulties in the sagittal native is to ask them to wear the plane as well as cervical and lumbar lightest possible sports outfit for this curvatures. procedure. With a 10 cm square rule A postural examination of Marie the examiner can visualize the extent reveals that her right shoulder is lower of shoulder and pelvic tilting in a

J Dentofacial Anom Orthod 2008;11:232-250. 241 ISABELLE GAULT

Figure 17 Marie.

Figure 18 Showing divergent feet and hypo-convergence of the right eye.

than her left. This can also be seen by be lower. In this type of case patients do an examiner bent over in front of the not hold their heads erect but tilt it to the patient where the difference in the right. If the examiner gently guides the height of the wrists can be noted, at head to an upright position such patients the level of the radial styloids. But feel ill at ease and tilt their heads back to examiners should take into account the original position. the fact that right handed people By placing cotton roll between the usually have right shoulders lower teeth the examiner can neutralize the than their left. signals sent out by the occlusion and Examiners can study the tilt of the patients will upright their heads pelvis by placing their hands on the iliac spontaneously thanks to this elimina- crest. For this patient, the right hand will tion of this faulty postural data.

242 Isabelle Gault. Correlations between orthodontic treatment and posture CORRELATIONS BETWEEN ORTHODONTIC TREATMENT AND POSTURE

Figure 19 Marie standing a: profile view, note anterior scapula; b: full face, right shoulder and ilium are lower.

Schema: a) profile view: scapula and Referring a patient to a physician head in advance; b) full face: head competent in posturology leaning to the right; c) full face: head When orthodontists prepare to treat becomes upright when cotton roll is patients with this type of problem, they placed between the teeth. should first refer them to competent This succinct assessment allows physicians who will take a careful the examiner to detect a postural history and carry out a full postural problem that ought to be corrected analysis with assessment of possible before orthodontic therapy begins. future pain sites. The examination will include the sagittal, the frontal, and the horizontal planes. The weight bearing • Case n 2 - Jules capability of the feet will be assessed This boy’s left shoulder is lower as to its distribution between the feet than his right, his right leg is bent, and and in forward and backward walking. the examination of his back proved to The physician will also evaluate the be most interesting. ocular receptors, will look for patholo- His left foot is valgus, turned out- gical scars, any blockage at any level of ward. An orthopedist would study him the spinal column, and for visceral barefooted. Unfortunately we usually mobility and motility problems. see our patients when they are wearing sneakers packed with "shock absorber" material that is quite harmful to the Postural treatment should be under- wearer’s posture. taken by a multi-disciplinary team His head and scapula are in an The goal of an orthodontist’s anterior position. taking postural evaluation is find out

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Figure 20 Jules.

Figure 21 His feet.

if any receptors are mal-functioning see them every four months the and to refer patients when indicated first year, then twice a year for to the proper specialist that might growing children. There are a variety be a podiatrist, an orthopedist, a of schools of thought in posturology physical therapist, an osteopath, or but they all agree on the importance another dentist. Physicians treating of correcting mal-functioning recep- patients for postural problems usually tors.

244 Isabelle Gault. Correlations between orthodontic treatment and posture CORRELATIONS BETWEEN ORTHODONTIC TREATMENT AND POSTURE

Figure 22 Head and scapula in anterior positions.

It is advisable to correct postural opposite directions. He was treated problems 4 to 6 months before with corrective shoes equipped with orthodontic treatment begins and then Bricot soles 4 months before he have it continue as orthodontic ther- began wearing a functional orthodon- apy proceeds. tic appliance and starting oro-facial myo-functional therapy. • Case n 3 - Maxime Pre-orthodontic postural therapy This 11 year old boy with a retruded makes it possible for myo-functional mandible had postural problems that treatment to work effectively and to included pelvis and shoulders tilted in have stable results.

Figure 23 Maxime.

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Figure 24 Maxime frontal view.

Figure 25 Maxime profile view.

Here one can see the straightening (2) 4 months after the beginning of of the scapular plane and the decrease postural therapy; of cervical curvature. (3) after completion of postural treat- (1) before postural treatment; ment and 6 months of functional therapy.

246 Isabelle Gault. Correlations between orthodontic treatment and posture CORRELATIONS BETWEEN ORTHODONTIC TREATMENT AND POSTURE

Figure 26 Re-establishment of Class I occlusion.

A Class 1 occlusion has been finishing procedures after which there quickly reestablished and will be fol- will be little risk of relapse. lowed by a period of full-banded

5 - THE SCOLIATIC PATIENT

Scoliosis is a curvature, and possible – scoliosis occurs most frequently rotation, of the spine that may be idiopathically during adolescence, congenital or the result of diseases 80% of the cases in girls occurring such as cerebral palsy or rickets. It is between the ages of 11 and 13 and characterized by progressive displace- 20% of the time in boys between the ment of vertebra with respect to each ages of 13 and 15; other in all three dimensions of space – usually scoliosis develops chaoti- with: cally and without warning. – lateral inflexion which reflects displacement in the frontal plane; • A clinical case – extension or flatness of the back This 12 year old girl had a malocclusion reflecting a displacement in the sagit- with no transverse discrepancy except tal plane; an impacted upper right cuspid. – a rotation reflecting a vertebral Treatment proceeded uneventfully until movement in the horizontal plane: a few months before the scheduled day appearing clinically as an abnormal of band removal when a serious curvature or bulge; mandibular deviation became apparent.

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When a postural assessment was orthodontistsshould beawarethat ortho- made a slight scoliosis was found. In dontic treatment may have some kind of consultation with the physician treat- impact on the spinal column. According ing the girl we decided to remove the to some posturologists the placement of appliances immediately so as not to an orthodontic appliance has a great interfere with the scoliosis therapy. As effect on the postural system. this physical therapy continued over If scoliosis is diagnosed before the the next few months the mandible beginning of therapy, orthodontists progressively moved back to its cor- should undertake treatment with the rect position. It will be necessary to utmost prudence! Dr. Bricot goes so wait for the end of the growth period far as to say that any full-banded to finish the orthodontic treatment orthodontic treatment should be post- while, of course, the spinal column poned until the end of the growth will also be closely monitored. period so as not to risk any adverse How should patients with scoliosis stimulation of the tonic postural sys- be treated orthodontically? tem. But Dr. Mauroy6 advises that There is a wide difference of opinion girls between the ages of 11 and 13 on this point; many physical therapists can began orthodontic therapy as long have pointed out that scoliosis often as the spinal column is kept under appears after conclusion of orthodon- strict surveillance and, if needed, tic treatment; others respond that the treated for scoliosis simultaneously. condition was probably preexistent. So, in these situations of postural risk, we should adapt our treatments or The cause and effect relationship is suspend them entirely. highly uncertain, but, at the very least,

Figure 27 Scoliosis.

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Figure 28 Removal of orthodontic appliances for scoliosis therapy.

Figure 29 Pelvis straightened mandible re-centred.

6 - CONCLUSION

Orthodontists should make postural during the course of mechano-therapy assessments of their patients before they should adapt it and, where treatment in order to detect any necessary, discontinue it. Orthodontic possible disequilibrium in the postural treatment can be a cause of serious system. If such a discrepancy is disturbances through deleterious in- found, multidisciplinary therapy may terference with the trigeminal nerve. be indicated. In all cases, orthodon- Not only our patients but also their tists should be aware of the totality of bodies should accept the treatment their patients’ over-all postural status. that we propose. If a postural discrepancy appears

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REFERENCES

1. Ait-Abbas. Occlusion et posture de l’enfant. Me´ moire pour DU d’occlusodontologie. Toulouse, 1992. 2. Bricot B. La reprogrammation posturale globale. Sauramps Me´ dical, 1996. 3. Bricot B. Effets de l’occlusion sur le syste` me postural. E´ tude de septembre 1999, Marseille. 4. Busquet L. Les chaı¨nes musculaires et traitement du crane. E´ ditions Busquet, 2006. 5. Clauzade MA, Daraillans B. Concept oste´ opathique de l’occlusion. 1989. 6. De Mauroy. La scoliose. Sauramps Me´ dical, 1996. 7. Meyer J. Participation des affe´ rences trige´ minales dans la re´ gulation tonique posturale orthostatique. Inte´ reˆ t de l’examen syste´ matique du syste` me manducateur chez les sportifs de haut niveau. The` se DSO, 1977.

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