Bite in sport

In recent years, the use of oral devices, more technically called bite or release plates, has become increasingly widespread among athletes of the most varied disciplines: in fact, recently data have emerged to support the existence of an effective correlation between the equilibrium of the stomatognathic and locomotor systems. Dental occlusion seems to be able to play an important role on body posture. In the light of the most recent acquisitions, it seems certain that a malocclusion can actually have a “downward” impact on postural attitude.

In high-level athletes, posture requires perfect adaptation to gestural activity since a change in balance, even if modest, can translate into variations in the intensity of strength and coordination skills, ultimately affecting sports performance.

Any dental problem (from serious orthodontic problems to a banal restoration due to caries not correctly carried out) can lead through a non-physiological chewing to a displacement of the mandible from its correct position with respect to the upper jaw, ie a “mandibular dislocation” occurs.

If mandibular dislocation is diagnosed after a thorough dental examination, it is necessary to deepen the investigation with an applied kinesiology test and a computerized stabilometric platform to confirm any diagnosis of pathology or postural imbalance.

The therapy of a malocclusion must take into account the resolution of the problem that caused it, for example the insertion of prostheses where the teeth are missing, or the extraction of an eighth grown in disodontiasis. In the first therapeutic phase, bites are often used, this phase is always or almost always considered an occlusal therapy, temporary or provisional, sometimes diagnostic, which allows to modify the pre-existing occlusal scheme, in a very short time, without intervening massively on the patient’s dentition. All this makes this therapy extremely adaptable to the needs of the athlete given the speed and low invasiveness of the technique. The aim of our work was to evaluate the changes in strength, weight distribution on the lower atria and the position of the center of gravity resulting from the correction of dysfunctional attitudes through the packaging of an adequate bite.

The occlusion

By occlusion we generally mean any relationship between the arches when even only some of the respective teeth come into contact with each other, both with the jaw stationary and during the functional movements of the temporomandibular joints.

Normally, in the rest position, the teeth are not in contact, but the two arches are separated by a freeway space. In a situation where the stomatognathic apparatus works properly (habitual physiological occlusion), when the two dental arches occlude (swallowing, the terminal phase of chewing), they do so in the most stable position, i.e. the one characterized by the maximum number of contacts between antagonistic elements (position of maximum intercuspation), with uniform distribution of masticatory loads, respecting the periodontal structures, masticatory muscles in normal tone and asymptomatic temporomandibular joints.

This equilibrium situation is therefore linked to several interrelated factors:

the shape of the dental arches
the temporomandibular joints
the chewing muscles
neuromuscular control.

Any variation in one of these four components introduces an alteration in the balance which, when it exceeds the subject’s ability to compensate (very variable from person to person), leads to a pathological situation. Given the relative rarity of primary diseases of the muscles and joints, the main causes of occlusion-muscle-articular disorders are to be found in alterations in neuromuscular control (bruxism) and in alterations in the shape of the dental arches.

It is difficult to define a criterion of “normality” of the shape of the arches, since in reality it is possible to observe wide anatomical variations of the arches in the absence of pathology. However, there are morphological canons that are traditionally identified as “ideals”:

the maxillary arch, being slightly wider, protrudes buccally with respect to the corresponding mandibular, partially covering it.
At the level of the incisors, this overjet on the sagittal plane is about 2 mm, while the distance between the free margins (overbite) is 2-2.5 mm;
with respect to a horizontal plane all the teeth show a certain degree of inclination which allows to identify two curved lines with superior concavity on the sagittal plane (Spee’s curve) and frontal (Wilson’s curve).

The occlusal plane is instead the imaginary surface tangent to the cusps of all the teeth of the two arches in occlusion; in this case the elements of each arch are harmonically aligned with correct contact surfaces. In the mesio-distal sense, the upper canine occludes between the lower canine and the lower first premolar (first class canine), while the first upper molar is located distal to the corresponding lower for a space corresponding to half cusp (first molar class). The lingual cusps of the upper teeth and the buccal cusps of the lower teeth articulate with the opposing occlusal surfaces in three points and are called mold cusps, while the buccal cusps of the upper teeth and the lingual cusps of the lower teeth do not articulate with any antagonist fossa and do not therefore they have a support function, but guide the mandible in lateral movements (cutting or guiding cusps). During the protruding movement of the mandible, the sliding of the lower incisors on the palatine surface of the upper guides the disclusion and “protects” the posterior teeth by forcing them to move away from each other (incisive guide), while in lateral movements the disclusion occurs on the canines (canine guide ).

Causes of malocclusion

The causes that produce a malocclusion are very difficult to classify; we can however consider:

genetic malocclusions (intermaxillary and / or dento-bony discrepancies)
malocclusions secondary to bad habits (e.g. open bite from finger sucking)
malocclusions secondary to trauma (outcomes of fractures of the jaws, dislocation of the mandible)
malocclusions from untreated edentulism (diffuse caries, periodontal diseases)
malocclusions due to iatrogenic causes (incongruous conservative and prosthetic restorations, incorrect orthodontic or gnathological therapies).

From the pathophysiological point of view, although it is possible to witness very variable situations, it can be said that the establishment of a pre-contact involves the loss of stability of the occlusal contact and the deviation of the position of the mandible. The subject will then try to adapt by seeking, partly reflexively and partly consciously, a new stable position, which however involves variations in the position of the condyles and muscle tone.

If these variations exceed the adaptability of the aforementioned structures, a habitual pathological occlusion develops in which intercuspidation is noted in the presence of muscular dystonia and symptoms in the temporomandibular joints. Often a vicious circle arises whereby the pathological occlusion does not remain unchanged, but changes over time.

Damage can occur in the hard tissues of the tooth (abrasions), in the periodontium (bone resorption, tooth mobility, gingival recessions), in the muscles (spasms, myofascial pain) and in the joint (reducible condyle-meniscal dislocation, condyle dislocation) irreducible meniscus, arthrosis). In general, the “weak link” of the chain yields, although more often joint, muscle, periodontal and dental damage coexist.

Posture

Posture is the attitude that the various body segments assume in the surrounding environment through the contraction of skeletal muscles; it is integrated and coordinated by a series of stimuli of various kinds that determine a continuous adjustment of the neuromuscular type.

It is good to clarify that there are an infinite number of postures: they correspond to any “position in equilibrium”, with maximum balance (stability), maximum economy (minimum energy consumption), maximum comfort (minimum stress on anatomical structures).

Posture is the way of keeping the human body in balance whether it is stationary or in motion. This balance is the result of the adaptation of various structures of the body such as central nervous system, spine, limbs and their interconnections with the outside world. The standing position, which is characteristic of the human species, is one of the innumerable postures and is characterized by the vertical alignment and the support of the two feet on the ground. It is a posture rarely used in everyday life, but which nevertheless is useful for us as a reference position.

The skeletal parts rest on the feet and are supported in equilibrium by the tension of the ligaments, by the aponeuroses, by the elastic properties of the muscles and by a minimal active contraction of the motor units, i.e. the functional units of the muscles.

Muscles are the organs that maintain balance in an upright position by adjusting the projection of the center of gravity within the support surface; they maintain the posture of any part of the body and promote the movements of the body or part of it, opposing the effects of gravity. Muscle action is continuously modulated and coordinated at the level of complex central nervous system devices that use sensory emissions from the neuromuscular spindles and Golgi muscle-tendon organs, as well as from the joint receptors and the membranous labyrinth.

The motor emissions are discharged from the central nervous system on the extrafusal and intrafusal striated muscle fibers via the motor neurons a and g. The central nervous system thus becomes responsible for the muscle tone, that is, the slight tension that the striated muscles present at rest by correctly maintaining the positions of the relative parts of the body and opposes the passive modifications of these positions.

The muscles, in addition to the static balance, determine the movements of the locomotor system, which are also regulated in a very complex way by the activity of the central nervous system. In the relaxed symmetrical standing position, the hip joints, as well as those of the knees, assume a position of full extension as they have to bear the weight above. In static equilibrium, in the standing position on two feet, the vertebral column extends upwards from the base of the sacrum, on the median sagittal plane, with three physiological curves that run in front and behind the line of the center of gravity. This line moves vertically from the tooth of the axis, through the center of the first two thoracic vertebrae, to the lumbosacral promontory; from here the line proceeds to the support base of the soles of the feet.

The three physiological curvatures are: the two lordoses: (the cervical and the lumbar which have anterior convexity) and the dorsal kyphotic curvature (posterior convexity). These three curves balance the spine by compensating each other; any variation of one of them, in fact, solicits simultaneous variations of the other two, within certain limits, to maintain balance.

The three curvatures are subordinate to the orientation of the support plane of the 5th lumbar vertebra on the plane of the sacral base; this plane describes, with the horizon, an angle of about 30 ° (angle of inclination of the sacrum or pelvis); this angle varies according to the inclination of the entire pelvis which can swing forward or backward, rotating on a transverse axis stretched between the two femoral heads. The postural structure of the spine, following changes in the orientation of the sacral support plane, varies especially at the level of the lordosis curves. The three curves, in addition to maintaining balance, also have a support function, in fact they must resist longitudinal pressures, given for example by gravity.

The stabilization of the physiological curves and the reciprocal dynamic compensations, aimed at maintaining balance, are largely guaranteed by the anterior and posterior longitudinal ligaments, by the yellow and capsular ligaments, by the interspinous and supraspinatus and also, in the cervical area, by the complex of the altloccipital ligaments. These ligaments constantly control the gravitational displacements both by elastically blocking the reciprocal translation of the functional units of the column and by favoring their elastic return in the equilibrium position. Also involved in the posture are, in a decisive way, the reflex variations of the tone of the intrinsic muscles of the spine; any passive mechanical event acts on the attitude of the spine and stretches the ligaments and the muscles themselves is capable of causing, in a reflex way, adjustments in muscle tone aimed at rebalancing the column. This occurs continuously in maintaining the postural attitude and in movement.

Even the articular surfaces of diarthrosis, having their own orientation and inclination, allow each section of the spine to have a highly specific displacement of one vertebra on the other.

The upper cervical spine, with the occipitoatloassoid complex, constitutes, for the characteristics of its vertebrae (C1-C2-C3), for the lack of intervertebral discs, for the absence of posterior joints and junction holes and for the power of the ligamentous and muscular complex, a block in itself specialized for the statics and dynamics of the head.

Extensive flexion-extension, lateral inclination and rotation movements take place at the level of the lower cervical spine, deeply engaging the C4-C6 segment. The dorsal spine is itself capable of flexion-extension, lateral inclination and rotation movements. Its mobility is partially blocked by the cost-sternal connections; the deformations that the rib cage undergoes in the execution of the movements of the trunk are easily visible.

At the level of the lumbar spine, the range of flexion-extension, lateral inclination and rotation movements is greatly affected by age. In conclusion, a good posture is that state of muscular and skeletal balance that protects the supporting structures of the body from a progressive injury or deformity despite the position (standing, lying, squatting, bent) in which these structures work or offer resistance. In these conditions the muscles will work more effectively, so a good muscle balance must ensure good alignment avoiding excessive tension and contractures of the joints, ligaments and muscles. Furthermore, each mass or body is composed of a multitude of small particles attracted to the earth as described by the force of gravity.

This attraction to which the particles of the body are subjected produces a system of practically parallel forces and the resultant of these forces acting vertically downwards is the weight of the body.

It is possible to locate a point where a single force can be applied which is equivalent, in intensity, to the weight of the body and which acts vertically upwards, in order to give the body balance in every position. This point is called the center of gravity or center of gravity, which can be described as the point where all the weight of the body is thought to be concentrated. The center of gravity is the exact center of mass of a subject.

If the mass, as in the human body, is distributed asymmetrically with respect to the horizontal plane, the center of gravity will be located proportionally closer to the largest and heaviest area. From some principles of statics we learn that there are two types of equilibrium:

static balance
dynamic balance

Static balance is the ability of an object or body segment or the body as a whole to maintain a static position. Dynamic balance is the ability to maintain, during the various actions of life, the body segments in a condition of stability. So the body will be all the more stable the lower the height of the center of gravity is compared to the height of the subject and the more the line of gravity is placed inside the support polygon.

The posture is registered in the motor centers in the form of a body scheme, that is, the knowledge that one has of one’s body in a static and dynamic situation, and once internalized, the adjustments of the correct posture depart.

The central nervous system regulates movement through motor patterns in which bones, joints and muscles play the role of mechanical executors in a whole regulated by the laws of neurophysiology.

When the individual moves, he interacts with the external environment, proposes his motor schemes and carries out a continuous modulation of exteroceptive and proprioceptive afferents leading to the formation of new motor schemes with functional characteristics. The development of motor skills consists in learning more and more selective and functional motor patterns and this is possible thanks to the large amount of tactile, kinesthetic, sensory information that reaches the central nervous system during the execution of motor acts. Posture can be considered as the result of a large number of integrated sensorimotor reflexes, at different levels of the central nervous system, with an extremely precise automatic regulation.

The mechanism that regulates posture receives information from the external or internal environment through sensory systems, such as the retina, skin and labyrinth, and from the Golgi tendon organs and neuromuscular spindles. These stimuli are transmitted to the higher centers, which include the brain, cerebellum and brainstem, through the interneurons and motor neurons a and g present in the spinal cord.

Once the information reaches the central nervous system, it is processed and subsequently transmitted to the muscles, where the contraction of the muscles occurs, causing the movement of the skeletal levers and a consequent stabilization of the posture.

The altered functioning of only one of these impulses causes an alteration of posture and the probable onset of a pathology.

The fine postural system

The fine postural system is a very detailed and precise control of posture through the aid of stabilometry. The stabilometry shows the power of discrimination of the receptors of the postural system and allows to regulate the stabilization phenomena with incredible precision.

The sensitivity of the receptors of the postural system is not the same for fine movements and for gross movements, since the receptors are much more active for the former, consequently their response curve to stimulations involves a difference in perception between the two. movements. This is examined by stabilometry from both a sensory and motor point of view, using the discriminating receptors of sensory information and motor information that maintain postural stability.

The discriminating receptors of sensory information are:

Vestribular receptor

The semi-circular channels do not intervene in the control of posture; as their perception threshold is too fine to be controlled by stabilometry.

Otoliths are therefore the only vestibular receptors that can play a role in the control of postural oscillations and / or in the control of orthostatic postural tonic activity.

Proprioceptive receptor

Postural oscillations involve slight strains that cause the activation and consequent response of the neuromuscular spindles.

Therefore, the muscular proprioceptive information received by the fine postural system is particularly precise and discriminating.

Visual-oculomotor receptor

The detection threshold of the movement of sight by the paracentral and peripheral retina does not intervene to differentiate the perception of the fine postural system.

The importance of the retinal displacement depends on two factors: the amplitude of the posture oscillations and the distance of the visual scene; at the same distance, the retinal displacement increases with the amplitude of the oscillations; at equal amplitudes the retinal displacement decreases as the distance of the visual scene increases.

Pathophysiology of occlusion-postural dysfunctions

The causes of mandibular dislocation can be many, but the most frequent are pre-contacts, i.e. when at the moment of occlusal contact one or more cusps or slopes of cusps touch, before the others, the surfaces of the antagonist tooth.

Once the pre-contact has appeared, the neuromuscular system, to avoid it, programs new motor patterns and finds a new occlusal position by displacing the mandible. The avoidance reflex then generates a new pathological habitual mandibular position.

This reflex is induced by the neuromuscular system which is most likely stimulated by the overload impressed on the periodontium by the precontact. Not being a first choice motor pattern, the motor avoidance reflex implies a greater expenditure of energy and greater muscle suffering to maintain the new pathological and non-ergonomic posture. Furthermore, the new motor scheme of accommodation of the displaced mandible is modulated by the reticular substance, which plays a very important role in anxious states, in the sleep-wake rhythm and in the genesis of parafunctions. More precisely, the mandibular dislocation occurs through these steps:

Pre-contact

periodontal nociceptive alarm
avoidance reflex
new pathological posture

In mandibular dislocation due to precontact, the deviation occurs contralaterally with respect to the precontact itself.

The sternocleidomastoid and trapezius muscles are the first mediating muscles between the posture of the system between the stomatognathic system and the rest of the body: they are involved in compensating for the imbalances generated by masticatory muscles, especially by the lateral pterygoids.

The functional disturbance of a sector causes imbalances in the neighboring sectors, which are transmitted to the end of the postural chain. The mandible, forced to dislocation to avoid unacceptable occlusal contacts, produces a tiring muscular accommodation descending along the postural chain. Automatic compensation is generated to restore the indispensable balance of the body but all this involves a high energy expenditure and muscle fatigue that greatly affect the performance of the athlete and prolong the recovery time.

Therefore it is necessary to reduce or minimize the energy expenditure in the athlete due to the compensation of muscle imbalances present at any level of the postural chain. If the mandibular dental arch does not match perfectly with that of the maxillary, but is further back, further forward or even slightly laterally displaced, by clenching the teeth some of these muscles are constantly tense (in spasm) and others always inert (in hypotonia) .

The same happens when there is one-sided lack of teeth; in fact, this can have the same effects on the chewing muscles. This imbalance between their tensions is a serious problem because they are strong muscles and contact between the opposing teeth occurs continuously, even if unconsciously.

The hypotonia and spasm that occur on the two opposite sides of the skull, discharge on a series of other muscles of the neck and back, which, forming a muscle chain, affect the skull, spine, pelvis and the whole body. The body then, trying to compensate for the imbalance, “twists”. Due to this decompensation, the agonist and antagonist muscles work in disharmony by sending alarm messages to the brain, which in turn mobilizes other muscle structures to stabilize the correction, burning other energies. . The imbalance between muscle tension and the constant work to compensate disperse much of the muscle strength when maximum performance is required.

The close connection of interdependence between the craniomandibular structures, the cervico-thoracic-lumbosacral spine, the shoulder girdle, the pelvic girdle, the hip, knee and foot joints, now has interdisciplinary consensus. All these structures constitute the so-called postural chain; this connection means that the imbalance of a district is rarely limited, but more often it is transmitted to neighboring ones and then to all the links in the chain.

The postural chain is vertical; the imbalance of the highest ring can be transmitted to the others only in a descending sense, the lower one only in an ascending sense, the intermediate one in both directions (often with different entities).

Once the occlusal pathology has been established, it is not easy to return to the initial situation, precisely because complicating effects occur on the nervous and muscular level, so the elimination of pathogenic noxa is not necessarily followed by the disappearance of the symptoms.

If an occlusal disharmony is established, such as a pre-contact at the level of the molars in maximum intercuspation or an interference in the protrusion or lateral movements, the mandible would find itself working as a type I lever that would tend to undermine the joint, as the pre-contact becomes the fulcrum, the muscles the power and the TMJ the resistance.

When the jaw encounters interference, the possibilities of an adaptation would in all likelihood occur with a protruding slip; in fact, the TMJ is anatomically predisposed to displace anteriorly, through the contraction of the lower head of the lateral pterygoid.

This muscle will present painfulness on palpation due to the state of contracture it presents.

Motor skills

To carry out any motor and sporting activity, functional prerequisites consisting of motor skills are required.

Each motor act is the expression of an interaction between the individual and the environment: motor skills are manifested through anatomical-physiological, psychic, cognitive and socio-cultural factors.

The term motor ability has a very specific meaning: “ability” indicates the attitude that is defined by maturation and which is a prerequisite for the execution of a movement; “Motor” instead qualifies the aspects that influence movement, both in quantitative and qualitative terms.

Motor skills can be:

Conditional skills or the set of factors related to the morpho-functional characteristics and the efficiency of bioenergetic processes and therefore connected to the organic muscular conditions;
Coordination skills or the processes of maturation of the nervous system, which allow you to organize, control and regulate movement.

There are physical properties that are indispensable to be able to perform any physical work. We can thus classify:

Properties that fall under conditional capabilities

Power
Resistence
Quickness or speed
Flexibility

Properties that fall within the coordination skills

Motor learning skills
Learning and transformation skills
Ability to control movements

These properties, during the execution of the athletic gesture, blend together and it is difficult to distinguish them.

In sports, they can be divided into general and fundamental:

General physical properties

flexibility
coordination skills

Fundamental physical properties

maximal strength
force fast
strength resistance

Fundamental properties take priority over general properties.

Let’s analyze these properties better:

Flexibility is the ability to make movements using the maximum excursion allowed in the joints.

It allows you to easily learn motor actions, to perfect and assimilate new movements in a short time, to rationalize energy expenditure, to perform fast movements and delay fatigue.

Coordination skills allow you to know how to dose and adapt the behavior of the body in the execution of various motor tasks in the surrounding environment.

Strength is the property of the neuromuscular system to express tensions and to cause contractions that can be isometric, concentric, eccentric.

In the isometric contraction there is no stretching of the muscle, with the production of tension; in the concentric contraction the muscle works in shortening; in the eccentric contraction the work is in lengthening.

Resistance to fast force allows you to face a race course with determination and safety; in fact, it allows dynamic weight changes, rapid reversals and the ability to keep pace and fast recovery of any errors, which are the prerequisites for good performance.

Diagnostic procedure

For their evaluation, all the athletes were subjected to the following tests:

Anamnesis
Physical examination
Anthropometric parameters
Postural visit
Radiographic examination: orthopantomography

Anamnesis

We have collected for each athlete the most accurate medical history possible that considered all the problems affecting both the stomatognathic system and the postural and general ones. We have taken into account previous traumas, but not only of the cephalic district as it is known for example. how a whiplash can trigger a TMJ pathology.

In cases where the athlete has presented pain, we have taken into account the primary area of onset, the areas of diffusion, the time of disappearance and the triggering or modifying causes. We investigated the possible existence of bruxism, clenching and a bad habit (sucking of the cheeks, atypical swallowing).

Physical examination

The first step of the visit was the inspection: once the athlete was in an upright position, we looked for any asymmetries of the face and posture of the body, neck or shoulders (in some cases the symmetries were so evident as to guide us at first view towards a diagnosis).

We carried out a first examination of the dental relationships to highlight any malocclusions (for example 2 °, 3 ° class of severe Angle with deviation of the median line in maximum intercuspation). Such data confirms the presence of mandibular dislocation. The face will appear deviated in the lower third towards the same side as the displacement.

The next step was palpation; this is carried out on the points of emergence of the cranial nerves of the TMJ and masticatory muscles.

The nerves we examined are the supraorbital and infraorbital branches of the trigeminal.

The palpation of the muscles had an important diagnostic value for this reason we proceeded with the utmost care in order not to produce false positives. The examination was always performed symmetrically by comparing the homologous muscles on the right with those on the left, first with the mouth open and then with the mouth closed; we verified whether there were differences in tenderness between homologous muscles on the right and on the left (this data would have confirmed the diagnosis of mandibular dislocation.

We then performed the auscultation of joint noises; this examination showed us intra-articular functionality. We considered the type of noise, the intensity and the moment of its appearance. Where we recorded a sharp and short snap mostly indicated a displacement with condyle-meniscal incoordination and with deviation in the opening movement. Generally, the noise occurs at the beginning or at the end of the movement.

It is a less serious pathology when the snap is at the beginning of the opening and it is a slight noise; in fact, both the meniscus and the posterior ligament are not severely injured. If this diagnosis is correct, making the subject open fully and making him close protruding, the click disappears. We have often used the interposition of thicknesses with different heights between the arches to understand if an increase in the vertical dimension could restore the condyle on the meniscus.

A slightly more aggravated picture manifests itself with repeated clicks throughout the movement. In this case, both soft and hard joint tissues may have undergone morphological alterations. The most serious cases are those with noises of sand or rubbing; in fact it is a degenerative lesion of the joint tissues and they do not disappear either in a protruded position or by raising the vertical dimension.

In the presence of similar joint noises we have always carried out radiographic investigations with transcranial techniques aimed at verifying morphological alterations.

The next step is the analysis of static and kinetic occlusal relationships. We made a careful and accurate occlusal examination, which starts from the position of maximum intercuspidation and recording values of overjet, overbite at the incisor level, presence of malocclusions (deep bite, reverse bite, open, etc.), the type of occlusion according to the classes of Angle, the position of the lower midline relative to the upper one.

We then proceeded to check the occlusal contacts by performing lateral and protruding movements and also measuring the extent of the lateral and protrusive excursions.

Anthropometric parameters

To verify the existence of significantly different anthropometric variables in the four disciplines, the weight, height and Body Mass Index of the athletes were measured.

The Body Mass Index was calculated with the formula: weight (Kg) / height (m2).

Postural verification

The athletes we examined after the dental examination underwent a postural one.

The patient is placed behind the plumb line standing:

Later analysis
Frontal analysis
Lateral analysis

The patient is placed on his back:

Lateral analysis
Previous analysis

Postural mechanics:

Rotation
Inclination
Flexion and extension

Postural function test

Fukuda test
Postural Romberg test in the normal subject

Clinical kinesiological tests

Applied kinesiology is an effective method to discriminate between subjects with malocclusion and normal subjects.

It is necessary to test a muscle to identify the subjective strength, first with the mouth open and then with the mouth closed: in the case in which it is a subject carrying malocclusion there will be an instant loss of muscle tone as soon as the teeth are clamped, while a subject in normocclusion it will not have changes in muscle tone.

To identify a descending pathology we used the tensor of the fascia lata as an indicator (test of the tensor muscle of the fascia lata): we placed the patient in the supine position on a bed, the lower limb is stretched and raised at an angle of about 45 ° and the foot rotated inward.

We applied a force tending to bring the limb closer to the contralateral one, resting the palm of the hand, without squeezing the fingers, just above the ankle.

To diagnose an ascending pathology we used the deltoid muscle test: we placed the patient standing, with the arm raised at an angle of approximately 90 ° with the palm of the hand raised upwards.

Stabilometric and posturometric platform

During the experimentation, the posture 2000 platform constituted a fundamental diagnostic tool for undertaking postural corrective therapies.

The platform allowed the objectification and comparison of the initial and post-therapeutic postural behaviors of the various athletes. The stabilometric and posturometric platform is composed of two separable and adjustable half-footplates to adapt to the athlete’s physiology.

It detects the distribution of the weight of the subject on the two feet, in particular in three specific areas of the foot (I metatarsus, V metatarsus and heel) each of which corresponds to a single cell on the platform.

The sensors are load cells particularly sensitive to weight variations and able to perform up to a maximum of 60 measurements per second for each cell, recording and processing the loads and oscillations.

Vibration is one of the revolutionary elements of the platform, as it acts as an amplifier and not a disturbing element: it is a vibratory frequency of 20 Hertz that does not allow the platform to oscillate, thus not affecting the balance of the examined person.

With a few seconds of vibration (20-30) we simulated a movement test on the platform.

This exam differs from the examination of the foot support during walking, but instead simulates what can happen to an athlete after several minutes of activity and under stress.

A skier, for example, performs sporting activity while sliding and an examination of the foot support while walking would be completely inappropriate.

Placing the skier on the vibration platform, the negative effect of a scar on the sub-patellar ligament is highlighted, while this disorder may not appear during many other tests.

The athlete, as the vibration continues, tends to carry the weight away from the operated knee and this is extremely harmful for sports activities.

We divided the examination on the platform into three successive phases: in the first phase the patient was positioned on the platform, barefoot, trying to make him rest his feet in the position of greater freedom, but occupying the same position on the plates (which are equipped with yellow waving and red dots to check the symmetrical position of the feet). The athlete must look ahead by setting a reference point to keep his gaze engaged.

Looking at the window on the computer, we recorded the athlete’s behavior in a static standing position. The first phase, performed with the patient barefoot and with open eyes, is clinically significant when:

the weight is 5% or more off balance to the right or left
the weight is slightly unbalanced, but the barbell is not horizontal
one foot has drawn larger oscillations than the other.

In the second phase we carried out the same test but with our eyes closed. If there is no significant variation (ie it remains unbalanced as in the first phase) the cause of the imbalance will be sought in the locomor system (anamnestic research of any trauma), in the stomatognathic system or in limb discrepancies. If, on the other hand, the examination with eyes closed worsens, most likely the visual component is good and helps posture. If the oscillations or imbalance improve with the eyes closed, the visual afferents must be suspected of causing confusion in the postural system.

The third phase represents the continuation of the other two already examined. We got there already knowing the athlete’s pathological occlusion; for example we have placed cotton rolls in the seats in the case of dental blanks. The examination is carried out with the patient barefoot, with open eyes and with the interposition of special cards. In this way we have canceled all oral afferents and if the examination is improved it implies the involvement of the oral cavity in the postural pathology.

Radiographic examination: orthopantomography

Panoramic radiography was chosen as a diagnostic imaging method due to its ability to provide overall views of the dental arches and jaws. These radiographs thus allowed us to rapidly and accurately assess the factors most frequently involved in occlusal disorders: the dental formula and the temporomandibular joint.

The method proved to be very accurate for the diagnosis of the pathologies most frequently involved in the sports population (caries, eighths included, incongruous conservative treatments, osteoarthritis outcomes, etc.)

Therapeutic process

In sports, the first choice therapy for mandibular dislocations is the use of release plates: in fact, this therapy has multiple advantages.

Types of bite

In dentistry, occlusal plates are functional devices that have the purpose of correcting the displacement of the mandible by positioning it correctly.

The use of the plate is almost always a provisional or temporary therapy, sometimes diagnostic, because it modifies the previous occlusal scheme without irreversibility and without massive interventions on the teeth.

Then we will intervene with a definitive therapy which may be a selective grinding in cases of slight discrepancy between the arches.

In cases of greater discrepancy or where there are prosthetic needs, such as missing teeth, a prosthetic treatment is used (by addition).

Sometimes it is necessary to intervene with a surgical orthodontic treatment (displacement).

The occlusal plates can be constructed in different materials:

Resins
Metal
Printed plastic materials

The resins, which are the most used material for the construction of the bite, can be heat cured or self-cured.

All types of resin, both transparent and the color of natural teeth, can be used and both braces and orthodontic devices can be added.

The metal plates that have the advantage of a long life, can be in precious alloy or in non-precious alloys, such as stellites.

Plastic materials have proved to be the best for adapting to the needs that arise in the sports field.

The reasons for adopting dental therapy with bite to correct occlusal problems in athletes are:

speed of intervention
ability to make quick changes
reversible occlusal modification

The bite used for athletes are different from the plates used in dentistry, because they must respond to special needs given their use for performance at the limits.

Clinical Requirements for Athlete Bites

smallest possible footprint in the mouth
ease of arming and disarming
minimal stress on the teeth
good dimensional stability
well-polished contact surfaces
contours that respect the gums and mucous membranes
rounded edges to avoid tongue disorders
allow good phonation
allow good swallowing

The choice of the bite for the athlete

There is no sport in which the use of the bite is contraindicated, but there are great individual differences and between the various disciplines. In making the occlusal plates, plastic materials are preferred which, thanks to their different physical characteristics, allow a wide choice of consistency and excellent modularity. Materials such as Erkolok, one of the most used in the production of bites for sports use, allow the creation of plates with a diversified consistency: the internal softness ensures comfort for the athlete and the occlusal rigidity guarantees dimensional stability.

The consistency of the construction material makes the bites classified into:

soft
semi-rigid
rigid

Even if from our experience the compatibility with the single athlete seemed preponderant, it seems appropriate to give some simple guidelines for the choice of the bite in relation to the sport discipline.

In predominantly anaerobic sports where high intensity performance takes place in a short time, rigid bites (Erkodur) are preferable, which force the jaw into a fixed position even in situations of great occlusal stress (speed running, alpine skiing).

Soft bites are to be preferred in medium intensity sports prolonged over time, where the presence of a rigid foreign body in the mouth would be intolerable and an impediment to breathing and swallowing.

Some sports specialties (motorcycling and motor racing) allow and encourage the establishment of parafunctions, doors and windows and bruxism; in these, semi-rigid bites (Erkoflex) seem more suitable, able to prevent and compensate these occlusal problems without being too bulky and annoying.

In some sports, where it is necessary to protect the dental arches and where the use of mouthguards is common, the latter can be made as a functional plate adding the occlusal purpose to the normal protection from trauma.

Depending on the sport taken into consideration, it is necessary to keep in mind the specific accessories that the athlete wears during training and in the competition; just think of the stresses that the helmet of a motorcyclist or car driver inflicts on the jaw.

Our experimentation, taking into consideration twenty-five young athletes as a sample, has shown that the incidence of occlusal pathologies is high and not negligible. The oral pathologies that we have encountered most frequently are the problems of disodontiasis of the wisdom teeth, orthodontic problems and carious processes.

We have not always found a dental pathology, but in certain disciplines, such as speed, sports activity significantly favors parafunctions, especially window and door.

In these cases the bite is an indispensable aid to avoid that these forces, which for sports such as motorcycling can last for hours, cause serious damage.

With regard to postural pathologies, high-level athletes are subject, with a higher incidence than the remaining population due to physical activity brought to its maximum limit and to pathologies caused by injuries (from physical contact, from falling, see downhill, motorcycling, etc.) typical of each discipline.

In certain sports it is advisable and often indispensable to use a protective bite to reduce the outcome of trauma to the dental arches.

Through a careful postural analysis and a posturometric and stabilometric evaluation, carried out both in the usual situation of the athletes and after the necessary oral corrections, the close correlations existing between the stomatognathic and locomotor systems have been demonstrated.

Our study highlights how, by restoring correct occlusion, the postural structure improves, which gives the athlete an increase in balance, stability and centralization of the center of gravity.

We can thus confirm the existence of an improvement in the use of muscle strength (investigated by us only in some athletes), in endurance and therefore in athletic performance due to the improvement of balance and stability.

In sports such as alpine skiing, where the maintenance of a central distribution of the load is of fundamental importance, it has been seen that, increasing the vertical dimension with a bite, it was favored in cases of retraction of the center of gravity an advance of the same; the correction of setbacks due to occlusal pathologies has given a notable improvement in sports performances.

The improvement of the postural structure also improves the athletic gesture as the athlete is able to fully use and optimize his motor skills.

This last aspect assumes primary importance in endurance sports where the achievement of the sporting result is not based on explosive strength but on the maintenance of a medium-high intensity effort over time.

A non-negligible consequence of the improved postural structure is the lower risk of the athlete to suffer functional injuries, such as stress fractures and muscle tears, this preventive aspect plays an important role that can allow the athlete to have a better state of general well-being and consequently less psychological stress

In many sports it is important to underline how some accessories can affect the occlusion.

In the case of motor sports we have shown how the use of the helmet, through strong pressures on the jaws, conditions evident displacements of the jaw and consequent postural variations.

It seems important to us to highlight how the use of a simple and non-invasive method such as the bite through the acquisition of greater coordination can affect a decrease in the risk of injuries and pathologies from overload.

BIBLIOGRAPHY

D. S. Walther : «KINESIOLOGIA APPLICATA» (Synopsis, Systam D.C., 1998)
F. Mongini: «LE CEFALEE E IL DOLORE FACIALE» Utet Torino, 1998)
R. S. Milani, D. D. De Periere, L. Lapeyre, L. D. Pourreyron: «Relationship between dental occlusion and posture» (Cranio; 2000, 4)
A. Pelosi, A. Caronti: «Verifica dei tests di kinesiologia applicata con pedana stabilometrica » (Atti del II° Congresso mondiale di kinesiologia, Garda, 1995)
G. M. Esposito: «Problemi posturali di pertinenza odontostomatologica » (Atti del II° Congresso mondiale di kinesiologia, Garda, 1995)
M. Zucchi: « Il bite » (Atti del II° Congresso mondiale di kinesiologia, Garda, 1995)
W. D. Mac Ardle, F. I. Katch, V. L. Katch: «FISIOLOGIA APPLICATA ALLO SPORT» (Casa Editrice Ambrosiana, 1998)
F. Guidetti, M. Tassinari, P. Gioffrè, R. Galletti, P. Pederzoli: «Propriocezione stomatognatica e rachidea: controllo posturale » (Dental Cadmos; 1993, 6)
M. G. Vinguerra, M. Partenza, M. Agelao, A. Filoni, P. Cellocco «CORRELAZIONE TRA PATOLOGIE DEL RACHIDE E DISFUNZIONI DELL’ATM MEDIANTE STUDIO BAROPODOMETRICO COMPUTERIZZATO» (Italian. J. Sport Sci. 2000; 2)
V. De Mola, G. Montaruli: «ODONTOIATRIA E POSTURA: AMBITI, LIMITI, PROSPETTIVE» (Doctor OS 1999; 9)
D. Urzi, G. Bavaresco, E. Crivellaro, A. Beghi, E. Mantovani: «PRESENTAZIONE DI UN PROTOCOLLO DIAGNOSTICO INTERDISCIPLINARE PER LA VALUTAZIONE DEL SISTEMA POSTURALE» (Doctor OS; 1998, 3)
A. Bonaccorso, T. R. Tripi: «DISTURBI SULL’ATM E DISFUNZIONI CERVICALI: POSSIBILI CORRELAZIONI» (Dental Cadmos; 1998, 2)
G. Massaiu, G. Toxiri : «SCOMPARSA DEI SINTOMI “ACCESSORI” DURANTE IL TRATTAMENTO DELLE DISFUNZIONI DELL’ATM)» (Il Dentista Moderno;1998, 4)
A. Luglio : «PATOLOGIA DELL’ATM: ESPRESSIONE SINTOMATOLOGICA DI SINDROME POSTURALE» (Il Dentista Moderno; 1998, 10)
F. Mongini: «ATM E MUSCOLATURA CRANIO-CERVICO-FACIALE. Fisiopatologia e terapia» (Utet Torino; 1996)
R. Ridi, F. Rossi: «GUIDA ALLA CLASSIFICAZIONE, VALUTAZIONE E TRATTAMENTO DELLE DISFUNZIONI CRANIO-MANDIBOLARI-POSTURALI» (Bollettino di informazioni ortodontiche, 1997, 56)
G. La Torre, L. Marigo: «L’EZIOLOGIA MULTIFATTORIALE NEI DISORDINI DELL’ARTICOLAZIONE CRANIO MANDIBOLARE» (Doctor OS; 2000, 6)
M. Libertucci: «DIAGNOSI E TERAPIA DEL DENTE “NEUROLOGICO”. DUE CASI CLINICI » (Il Dentista Moderno;1992, 9)
N. Veltri, C. Romano, M. Stenco, D. Bono: «RAPPORTO TRA FUNZIONE, PARAFUNZIONE, OCCLUSIONE E ALTERAZIONE DELLA POSTURA CERVICALE.» (Il Dentista Moderno;1994, 5)
I. Cavallaro, M. Fedele, F. Giancotti: «OCCLUSIONE E POSTURA »(Il Dentista Moderno;2000, 5)
U. Misitano, A. H. Christensen, E. Misitano, F. Misitano «Disfunzioni atm. SEMEIOTICA ODONTOIATRICA» (Rivista di odontoiatria degli amici di Brugg; 1996, 4)
F. Misitano: «L’ESAME OBIETTIVO DELLE STRUTTURE CRANIO FACCIALI» (Il Dentista Moderno;1985, 3)
M. Procaccini, E. Baldoni, L. Sorrentino, L. Santinello: «APPROCCIO DIAGNOSTICO NELLE PATOLOGIE DELL’ARTICOLAZIONE TEMPOROMANDIBOLARE» (Il Dentista Moderno;1993, 2)
N. Veltri, F. Basile, S. Giammatei: «POSTURE ERRATE: KINESIOLOGIA APPLICATA. DIAGNOSTICA E TERAPEUTICA IN CAMPO ODONTOIATRICO» (Doctor OS; 1992; 8)
A. Benfenati, C. Diolaiti «IPOTESI DI PROTOCOLLO CLINICO DELLE DISFUNZIONI CRANIO-CERVICO-MANDIBOLARI» (Il Dentista Moderno;1992, 3)
H. Iwakasi, R. Inaba, H. Iwata: «Biting force and physical fitness in athletes» (Nippon Eiseigaku Zasshi;. 1994, 8)
A. Aloi: «Effects of mandibular appliances on athletic performance.» (Cranio Clin Int.; 1991;1)
R. Mason: «SPORT TMJ DYSFUCTION. CASE REPORT» (Aust. Dent. J.; 1992, 12)
M. Roettger: «MANDIBULAR REPOSITIONING TO ENHANCE ATHLETIC PERFORMANCE: IS IT WELL FOUNDED? AND MORE IMPORTANTLY, IS IT SAFE?» (Aust. Dent. J.; 1992, 12)