Dental mobility

Dental mobility

-Etiologies and classifications

-Therapeutic strategies

Dental mobility is a very ancient pathological symptom if we refer to the discoveries of retention elements among the Egyptians.

Currently, increased tooth mobility, a symptom of periodontal disease, remains one of the clinical factors that most often leads patients to consult their practitioners. It is therefore important to diagnose the cause, then consider etiological therapy and, as a last resort, symptomatic therapy if etiological treatment is not feasible.

definition of tooth mobility:

Mobility is defined as an increase in the amplitude of movement of the tooth in its socket under the effect of exerted forces.
This is the result of the decrease in height of the supporting tissue and/or the increase in the width of the periodontal space.

Factors of variation in dental mobility:

Dental mobility depends on the tooth’s ability to react to the forces exerted on it, these forces are differentiated according to their:

– Direction

-Intensity

-Duration of the action

-Frequency of forces

-Location of the rotation point.

The different types of tooth mobility

There are different types of tooth mobility:

-Normal physiology.

-Abnormal pathology includes:

Reversible mobility
The irreversible mobility that can be
- increased, which does not change over time,
- growing which presents an unfavorable prognosis

Normal physiological tooth mobility:
1. Definition :

Physiological mobility is the result of a horizontal force exerted on a tooth surrounded by healthy or healed periodontium.

In the absence of any stress, the teeth exhibit spontaneous physiological mobility.
In the presence of occlusal stress, either axial or transverse mobility is observed.
In certain situations, dental mobility may increase temporarily for physiological reasons:

-Prolonged disocclusion during sleep.

Increased vascularity under the effect of vasoactive hormones such as sex hormones, during menstruation or pregnancy.

The phases of physiological mobility

The mechanism of mobility was studied in detail by Muhlemann in 1960:

The initial or intra-alveolar phase:

It is defined as the first phase of the movement of a tooth subjected to a labio-lingual force of 100g, we note:

-The crown begins to tilt in the direction of the force

-In the tension zone, there is a 10% reduction in the width of the desmodontal space, and an identical increase in the pressure zone.

Initial mobility depends on:

The height of the surrounding bone.
The width, structure, and organization of the periodontal ligament
The shape and number of roots present.
The value of initial dental mobility, the MDI of ankylosed teeth, is zero.

The MDS secondary phase:

It is measured after applying a labio-lingual force of 500g

The alveolar process is completely deformed.
Secondary tooth mobility in a healthy periodontium varies depending on the type of tooth. It is more significant in children than in adults.

Elastic recoil, slow recovery and periodontal impulse:

When the tooth stops acting, the tooth returns to its normal position in two stages:

the first : immediate recoil, elastic acts like a spring.

the second : slow and asymptomatic recovery movement.

Pathological tooth mobility:

As soon as the limits of the amplitude of physiological mobility are exceeded, we speak of abnormal or pathological mobility, it can be:

-localized

-generalized

Etiologies of dental mobility

The local etiology can have various origins: inflammatory, traumatic or mechanical.

The inflammatory origin is associated with either a pulp lesion or a periodontal lesion. The spread of inflammation from the gum into the periodontal ligament causes degenerative changes that increase mobility. The latter is also temporarily increased for a short period following periodontal surgery.

Similarly, aseptic or non-aseptic pulp inflammation can also spread into the periodontal space and lead to increased mobility of the affected tooth. In these cases, treatment of the periodontal or endodontic inflammation is sufficient to restore physiological conditions.

Mobility can also appear in certain specific cases, if there are sometimes anatomical situations where the apex of one or more teeth protrudes significantly into the sinus space (procident sinus); even without breaking of the sinus floor, the appearance of sinusitis can have repercussions on these teeth and cause completely reversible mobility with the disappearance of

inflammation.

Traumatic causes are either accidental (a shock) or occlusal .

The occlusal origin is represented by primary occlusal trauma related to a parafunction (tic, bruxism) or a dysfunction (prematurity, interference). Occlusal overload is most often associated with an increase in the desmodontal space (visible on radiographic images) which causes so-called increased mobility.

The mechanical cause is bone lysis linked to periodontitis , represented by a defective clinical crown/clinical root ratio, which increases the amplitude of displacement. The appearance of this abnormal mobility is linked to the length and shape of the roots, and also to the single or multi-rooted nature of the tooth. This mobility is not reversible, because it is linked to bone loss.

Certain general pathologies are associated with bone lysis and therefore dental mobility.

The association of occlusal overloads and bone loss in the teeth

Represented by destructive periodontitis in the presence of occlusal overloads. The desmodontal space is widened, angular bone lesions become visible on radiography and the teeth become very mobile.

3-2-Means of diagnosis

Mobility must always be linked to its etiology. For this, periodontal, occlusal, and radiographic examinations, along with a pulp vitality test, are essential in the face of dental mobility.

The anamnesis allows us to detect certain general pathologies related to mobility such as scleroderma, osteoporosis, hyperthyroidism.

Examination of the teeth , the practitioner must focus on checking

coronary integrity,
the presence of non-functional wear facets,
micro fractures or cracks which can be linked to trauma.
Pulp vitality must be checked, as well as the presence of carious involvement.
The quality of restorations, fractures of amalgams or enamel prisms,
the morphology of fixed prostheses and the stability of removable prostheses are all parameters to be noted.
- Assessment of dental mobility “mobility indices”:

The tooth will be moved by tapping it with a back and forth movement, either with the handle of two instruments (such as a mirror and probe) or between two fingers (thumb and index finger), or finally between the jaws of tweezers.

Muhlemann 1954:

Index 0: Ankylosis;

Index 1: Physiological mobility perceptible between two fingers; Index 2: transverse mobility visible to the naked eye;

Index 3: transverse mobility greater than 1 mm; Index 4: axial mobility.

Nyman Index 1975:

Index 0: horizontal tooth mobility 0.2 mm; Index 1: horizontal tooth mobility of 0.2-1 mm; Index 2: horizontal tooth mobility of 1-2 mm;

Index 3: horizontal dental mobility greater than 2mm and vertical mobility;

ADA Classification:

Index 0: physiological dental mobility;

Index 1: Horizontal tooth mobility less than 1mm;

Index 2: horizontal dental mobility greater than 1 mm without vertical direction;

Index 3: vertical tooth mobility.

ARPA Classification:

Class I: transverse tooth mobility perceptible to the finger; Class II: transverse tooth mobility perceptible to the eye; Class III: transverse tooth mobility greater than 1 mm; Class IV: transverse and axial tooth mobility.

Occlusal examination This involves looking for all signs of occlusal trauma, whatever they may be. Premature contacts, working or non-working interferences, occlusal overloads, parafunctions must be highlighted and linked to dental mobility. In all cases,

occlusal analysis must be done.

Examination of the superficial periodontium Any sign of inflammation should be noted, as well as the plaque/tartar/inflammation ratio. Recessions, signs of attachment loss or related to malposition, should be taken into account. This examination of the superficial periodontium should be repeated during the therapeutic phases in order to assess the evolution of mobility based on the regression of inflammation.

Deep periodontal examination Periodontal pockets are often directly linked to tooth mobility.

The modification of the crown/root ratio due to loss of bone support takes on considerable importance. These conditions can be considered as the only ones responsible for irreversible mobility.

Radiographic examination In addition to assessing alveolar bone lysis and the condition of the cortices

(lamina dura) which indicate the presence of periodontitis, several parameters must be taken into account. The widening of the desmodontal space can often be associated with reversible tooth mobility.

Root cracks and fractures should be sought as well as any signs of periapical infection (cyst, granuloma).

Therapeutic approach

-Emergency treatment

Mobility only requires emergency treatment in cases of acute desmodontitis “pain” or alteration of chewing and phonation, the emergency action will be immediate temporary retention and prescription of analgesic/anti-inflammatory medication for acute desmodontitis.

Reversible mobility

Eliminating the etiological factor allows for a rapid and complete return to normal.

Treatment of inflammation

Endodontic treatment
Surgical and non-surgical treatments for periodontal disease significantly reduce inflammation with or without temporary retention.

Treatment of occlusal trauma: occlusal splint, selective grinding, rehabilitation of existing prostheses.
Irreversible mobility
increased residual mobility due to decreased bone support is accepted as long as functions are not disrupted.

Quality plaque control and maintenance are essential for maintaining periodontal health and therefore residual mobility.

However, if chewing forces, even physiological ones, can become risk factors for increasing mobility either because the bone support is weakened or because the number of residual teeth is reduced, it is then imperative to move to permanent retention.

the restraint:
1. Definition of restraint:

Retention consists of joining one or more teeth that are too mobile, together or with less mobile teeth, so that:
- the loads they transmit to the periodontium do not contribute to the aggravation of pre-established lesions
- mobile teeth normally perform their assigned function
- teeth with reduced periodontium do not experience excessive forces
- possible surgical treatments can be undertaken without compromising the conservation of the most alveolyzed teeth.
In periodontology, we can say that retention allows some of the mobile teeth to be artificially maintained in the best possible anatomical and functional position, either temporarily, in the event of natural consolidation by tissue repair, or permanently to ensure the sustainability of the occlusal function when the stabilized periodontal lesions appear irreversible.

the role of restraint It allows:

Prevent pathological migrations.
Maintaining teeth after orthodontic treatment.
Facilitate scaling, curettage and periodontal surgery.
Reduce occlusal overloads that aggravate periodontal lesions.
Stabilize teeth in the best functional position.
Reassure the patient and encourage them to continue effective etiological therapy.

5-3. Goals of restraint:

Functional purpose

Aesthetic goal

Therapeutic purpose

5-4-Indications for restraint

If the patient complains of loose teeth that interfere with chewing and speaking functions.
If mobility is painful.
Risk of accidental dental avulsion or dislocation, for example when chewing.
If mobility increases over time despite suppression of inflammation.
To prevent relapses after orthodontic treatment of teeth that have migrated due to periodontal disease.

5-5-Contraindications to restraint There are two types:

Absolute contraindications
Relative contraindications

-Absolute contraindications They are rather biological in nature

Lack of hygiene of the subject.
Predisposition to caries, it is preferable not to use an intracoronary system on a mouth with polycavities.
The quality of the enamel: some teeth have brittle enamel and will not support anchors well.
Lack of patient cooperation.

-Relative contraindications These are of a technical nature

Importance of the pulp (young subject), there is a risk of devitalization,
the aesthetic factor: the aesthetic problem is partly resolved thanks to current techniques and the quality of prostheses,
the financial aspect nevertheless remains an obstacle that should not be neglected.

Principles
1. Mechanical principles
Polygon principle

If two mobile teeth are joined by a fixed prosthesis, for example, the system created will be mobile around the axis joining the two hypomochlions, that is to say a single direction of the horizontal plane. If three mobile teeth are joined by the same system, the whole thing then becomes stable by itself.
The imaginary line connecting the centers of rotation of each tooth determines a triangle of which each side represents a true secondary axis of rotation so that any movement around one of these secondary axes is canceled by the other 2.

Roy’s Principle: In 1921, Roy defined three mobility plans for each arch

-A sagittal mobility plan concerning the incisors.

– A frontal mobility plane, it forms a 90° angle with the sagittal mobility plane, it concerns the PM-M

-An intermediate mobility plan bisecting the two previous plans, it mainly concerns the canines.

According to the author, retention is ensured if teeth belonging to different mobility planes are brought together.

Principle of the terminal tooth (resistance of the posterior pillars):

The most vulnerable dental organs in a retention system are the terminal teeth. They are only attached to the system on one side, which makes them more exposed to external forces.
The retention will sometimes need to include one or more additional dental organs to terminate at a tooth with strong supporting tissue.

Vertical location of restraint system:

The retention system should be located as close as possible to the incisal, or occlusal, edge. This will provide better resistance to forces applied perpendicular to the long axis of the tooth (far from the center of rotation of the tooth).

Biological principles:

-Hygiene: The support must promote plaque control and allow self-cleaning.

– Maximum comfort for the patient check that the restraint system

Not irritating to surrounding tissues,
does not modify or distort the patient’s speech,
is as unsightly as possible.

-Respect for the function:

The retention must allow normal function; preliminary occlusal equilibration must always be carried out before placing a retention, particular care must be taken to ensure that the following equilibrium conditions are respected:

A good distribution of forces in PIM.
Absence of RC prematurity
Absence of working and non-working interferences in lateral and protrusion movements.
The elimination of non-axial forces on each tooth, as well as the correction of any pathogenic disharmonies.
Respect for coronary morphology.

5-7- Moment of restraint:

At the start of emergency periodontal TRT .

It provides relief to the patient by immobilizing painful teeth under pressure. It gives them confidence in the treatment being administered. It is often used to facilitate prophylaxis and to allow the periodontium to be cleaned up while waiting to decide on the actual therapeutic possibilities. The retention is then temporary .

During TRT:

To facilitate scaling or surgery. The retention is temporary.

At the end of treatment

It allows the patient to be observed for a more or less long period of time. It is also temporary and also after active orthodontic treatment.

After treatment: it is permanent .

5-8-Devices and techniques for restraint 5-8-1- . Temporary restraint

5-8-1-1. Temporary fixed restraint:

Proximal bonding

The aim here is to bond the teeth together by their proximal surfaces using composite blocks.

It is a very quick and aesthetic procedure, which can be useful in emergencies or when a retainer breaks. Essentially to improve patient comfort.

However, the small bonding surface makes it very fragile.

Ligatures:

Representing the most used mode of temporary contention, most of the time. They are only used at the level of the incisor-canine block whose morphology lends itself more easily to their creations.

🟒 Silk thread:

wire (30cm), a wire guide, easy to make using a No. 17 probe.
A double turn is made at the collar of the 1st right or left PM at the operator’s choice and it is stabilized with a simple knot.
From there, this ligature moves away from the neck to become, from the canine, suprasingular. A strand of the ligature passes on the vestibular and lingual sides.
They crimp the adjacent tooth between each tooth, the strands are stabilized by a double simple knot, the knot is located very slightly below the contact point, the teeth are crimped by the wire, from one side to the opposite canine where the ligature goes back down to surround the neck of the 1st ^PM .
Very quick to perform. This ligature can only remain in place for a short time because it becomes impregnated with saliva and fermentation quickly sets in, which is particularly unpleasant for the patient.
The silk thread ligature will be used to perform scaling and polishing on mobile teeth or as emergency TRT.

🟒 Metal ligatures:

A flexible Nickel Chrome wire with a thickness of 0.30 mm or 0.4 mm in diameter is generally used and is stretched around the teeth to be retained. A wire is wrapped around a tooth at the end of the series so that a vestibular head and a lingual head can be exposed.

Figure eight ligature:

A simple hoop is placed around the pillar located at one end of the series of teeth to be consolidated.
The lingual head comes in the vestibular position and The vestibular head comes in the lingual position, the heads therefore cross in the interproximal area. Continuing in this way, the two heads reach the pillar at the other end where a simple

hooping followed by a twist. The strand is placed in an interdental space for aesthetics and comfort.

Some authors recommend the installation of resin stops or embedding the strands in composite to prevent apical migration of the wire.

Ladder ligature:

It is suitable for cases where great strength is required, as the wire can be used in double use.
It can remain in place for a long time (several months).
It is adjustable and easily modifiable.
It consists of 2 amounts.
Most often done from PM to PM passing below the point of contact but above the cingulum like all ligatures.

First, the uprights are positioned and fixed by tightening the end of the wires very loosely. The approximately 5 cm long sections of wire, bent into a U, are then slipped and twisted into the interdental spaces, allowing the two heads to be held together interdentally using vestibular strands. The bars are finally completely tightened gradually and alternately.

These strands must be beaten back towards the free edge; some authors recommend this.

covering using resin which must be polished and have the same shade as the teeth for aesthetics and to allow for more effective long-term retention.

Machine stitch binding:

Starting from the neck of the premolar, two free strands of unequal length are kept. The shorter strand is pressed against the lingual surface while the longer strand acts as a shuttle and blocks the lingual wire in the interdental space between each tooth before returning to the VF of the adjacent tooth. This movement is continued to the opposite PM where the two strands are then twisted.

This ligature is easy to perform, but on the one hand, blocking the wires in the interdental space requires a relatively significant force, which may therefore be contraindicated in the case of

very mobile teeth whose position could not be precisely ensured and on the other hand a break in the wire requires the complete repair of the ligature.

The vestibular or lingual bonded thread

Composite splints have enormous drawbacks. Therefore, efforts have been made to strengthen them. The bonded wire is composed of composite studs and a thin metal rod. A steel wire (0.3 or 0.4 mm in diameter) or a braided or unbraided orthodontic wire (0.5 to 0.7 mm in diameter) will be used. The wire is shaped to fit the shape of the arch. This technique is simple, effective, and easily repairable. The metal rod ensures the rigidity of the retainer. But it must

be chosen thin enough to allow physiological mobility. The effectiveness of this technique is paradoxical, since the resin/metal synergy only occurs from a mechanical point of view and on a limited surface.

The Ellman Grid

This grid is applied lingually or palatally to mobile teeth. It is pre-cut and shaped

according to the anatomy of the supporting teeth in order to respect the embrasures.) After having put a first layer of composite on the teeth, we place the grid which we finish coating. It is a technique

simple but requires good occlusion control. It is fast, respects dental integrity, and allows good plaque control. And, its aesthetic detriment is low. The width of the grid and the thickness of the composite make the assembly quickly rigid, which can lead to a lack of physiological mobility. The thickness will often cause functional discomfort. Finally, its longevity is highly operator-dependent and fractures can occur in the event of a significant lever arm.

CRF fiber reinforced composite

This process is more resistant, by embedding a strip of fiber (polyethylene, glass, etc.) in the composite on the vestibular and lingual teeth concerned by the retention generally of the anterior block.

Technical

Loose teeth can be immobilized in the desired position by placing small amounts of composite in the buccal interproximal spaces, without prior etching.

This composite is easily removed after the lingual splint is placed.

Some brands of fibers must be handled carefully using tweezers (no contact with fingers) in order to maintain their plasma adhesive treatment (example: Ribbond – Biosplint, etc.).

Measuring the required length of ribbon:
While holding the teeth in the desired position, apply the tin strip (2mm wide). (It is easily shaped on the teeth to allow precise determination of the length).
Adapt this template to the interproximal areas using a composite spatula.
Once the length is measured, transfer the template to the tape and cut to an equivalent length.
Place the cut piece on a clean plate or in a bowl until ready to use.
Preparing the tooth for bonding:

Sharpen the enamel surface of the tooth using a micro-sandblaster or a diamond bur. If strong retention is desired, a 4/10 mm groove can be cut on the lingual surface of the teeth. Prepare the enamel as for bonding: cleaning with pumice powder, acid etching, rinsing, drying, application of a thin layer of adhesive resin followed by its light-curing.

It is advisable to carry out the following steps away from the light of the operating light. Excessive ambient light can cause the light-curing composite resin to set prematurely.

Ribbon preparation:

Apply a thin layer of unfilled resin to the cut piece of tape. Remove excess adhesive from its surface.

Once coated with adhesive, the tape is handled like a composite resin. To prevent premature polymerization of the resin, the tape can be placed in a safe box or, in the absence of one, away from light while awaiting use.

Installation of the composite:

Apply a thin layer of a hybrid composite restorative to the prepared areas

Setting up the ribbon:

Using a clean, gloved finger, compress the tape onto the composite previously placed on the teeth until the tape is in contact with the lingual surface of the teeth. Once the tape is in place, proceed to adapt it to the interproximal spaces using a composite instrument. To prevent any movement of the already adapted part, hold it with one finger as you progress from one interdental space to another.

Modeling and photopolymerization of the composite:

After fitting the strip to the teeth, remove excess composite. To minimize wear, leave a small amount of composite at the ends of the splint. Spread the composite over the cervical and incisal edges of the splint to achieve a smooth transition to the tooth.

Light-cure the splint tooth by tooth for 30 to 40 seconds (vestibularly and lingually) each time.

Apply a layer of composite resin to smooth the surfaces, then polymerize. To do this, use a moderately filled composite which provides a perfectly smooth surface while reducing finishing and polishing time.

A hybrid composite is placed in a thin layer on the splint and smoothed using a finger coated with unfilled resin (Bonding). After adding the surface composite, clean the interproximal spaces.

Check occlusion, finish and polish as usual 5-8-1-2- Temporary mobile retainer

🟒 Hawley’s plaque:

The most common method of temporary mobile restraint is to carry out

the immobilization of the teeth of an arch by means of a Hawley appliance comprising a continuous vestibular support wire, the tension of which is negligible, fixed on a palatal plate

acrylic The lateral handles ensure the tightening of the vestibular support wire, this device is used in orthodontics.

🟒 Bite plan and gutter:

Made on a plaster model on an articulator after recording the bite. This type of device most often only provides temporary, part-time support; the patient must remove it during meals and sometimes during the day for social reasons.

5-8-2-Semi-permanent contention “ intracoronary splints”:

Barrelle and Dargent described ambivalent splints that can be used either:

-When deciding to implement long-term temporary restraint 1 year or more before permanent restraint.

-When we have lost hope of keeping our teeth for a long time, we can only hope to prolong it for a few years.

The procedures can extend the life of dental organs considered to be very deficient by a few years, even 5 to 6 years.

🟒 Ceria-Cerosi process:

A trench is made on all the teeth of the affected arch.
The instrument allows you to make a furrow a good millimeter deep.
Two strands of twisted nickel chrome wire are cut to the size of the trench length, the twist is embedded in composite.

🟒 The Berliner splint This is the same system as the Ceria Cerosi splint except that the splint

is only interested in two adjacent teeth, therefore two by two, from the group to be contained. This makes repair easier, but it is more fragile. Control of the forces exerted on the tooth is average.

🟒 The pericoronary splint

Interested in the incisor-canine block,
horizontal groove is made at the level of each tooth,
in this groove is inserted a metal wire which makes a ligature in 8,
the wire is embedded in filling material,
the whole thing is polished.

🟒 Abjean’s U-shaped splint

Similar to the BERLINNER process.
Ensures better retention by replacing the rod with a rider whose ends are inserted into calibrated dentin wells.
These riders are then coated in composites

5-8-2-Permanent restraint

-Inlays and onlays

-Glued metal splints:

The sealed or glued metal splint is made of precious or non-precious alloy of the cobalt chrome type. The splint preserves vestibular aesthetics by its lingual location on unrestored and non-decayed pulped teeth.

The more severe the periodontal damage, the more it will be necessary to increase the anchors on the abutments to avoid partial detachments, a source of traumatic reinterventions. In these cases, the creation of calibrated dentin wells will be considered. After radiographic evaluation of the

pulp volumes, these 1.5 mm deep wells are drilled along a specific insertion axis, common to all the abutment teeth of the splint, preferably using a parallelizer.

-Fiber composite splint

-Permanent retention with a definitive ceramic bridge.

CONCLUSION

Any treatment for tooth mobility ultimately aims to restore comfort and occlusal and masticatory functions through harmonious occlusion ensuring tooth retention and good periodontal health. The indications for retainers are limited, but they provide great functional comfort. It is important to note that retainers do not restore bone volume, but they promote periodontal healing by reducing mobility and promoting hygiene.