Orthopedic therapy

Orthopedic therapy

Orthopedic treatments are part of the therapeutic arsenal available to treat skeletal abnormalities.

Their purpose is to modify the shape or relative relationships of maxillofacial structures.

Thanks to orthopedic therapy, it is possible to direct facial growth and take advantage of this change through mechanical devices activated to stimulate or, on the contrary, block the growth of a given region.

Definition :

Maxillary or facial orthopedics , or better orthognathics, is the art of significantly changing the architecture of the jaws, especially by changing their growth. Its aim is to guide maxillomandibular morphogenesis during growth. It is performed early and must be supplemented by orthodontic therapy to improve the occlusion of the jaws and thus prevent relapses.

It can be functional or mechanical:

Functional orthopedic therapy : uses muscular forces (intrinsic forces) through a device responsible for tissue rehabilitation.
Mechanical orthopedic therapy : uses active devices that directly modify the shape of the jaws (extrinsic forces).

Functional orthopedics :

Functional orthopedics is a therapy intended to modify or activate a function to change the shape of a structure.

Uses muscular forces (intrinsic forces) through a device responsible for tissue rehabilitation.

The activators:

Growth activators are functional orthopedic appliances that induce an unusual, reproducible, therapeutic mandibular bite position guided by occlusal, mucosal, or mechanical positioning.

This position generates an activation of the masticatory musculature and an orthopedic response , hence their name “activator”. The elevation and the mandibular hyperpropulsion constitute the inducing elements of the observed modifications.

Rigid activators:

The reference device is the Robin Monobloc (1902) which corresponds to a resin block fitting the internal part of the maxilla and the mandible and constructed using propulsion.

Andresen’s Class II activator (1931) :

The activator consists of a resin monoblock (built from a mandibular propulsion position), to which a steel vestibular band and a transverse expansion cylinder have been added.

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Andresen’s activator effects:

Orthopedic effects :

Andresen’s activator is used in hyperdrive, causes contraction of the lateral pterygoid muscles , which stimulates the activity of the mandibular growth centers.
Tensioning of the retropulsor muscles. This causes an inverse maxillary recoil force which is transmitted, via the activator, to the maxilla which is then slowed in its sagittal growth.

Orthodontic effects :

Molar egression.
Lingo-version of the upper incisors and vestibulo-version of the lower incisors.
Distal translation of the upper arch and mesial translation of the lower arch.

Age of application:

The time of choice is before the patient reaches peak growth.

Wear : 12 hours per 24 hours (at night); check every 4 to 5 weeks;

grinding of the lower posterior regions, after several sessions, which will allow egression of the molars and premolars.

indications for Andresen’s activator:

Class II/1 with mandibular liability without DDM.
Mesodivergence, hypodivergence of the bone bases.
Class II/2 transformed into class II/1 after overbite removal. Contraindications:
Long face.
DDM.
Skeletal gape.
Breathing difficulties (Asthma).

Andresen Class III Activator

Corresponds to a resin monoblock built in forced retropulsion, to which an Eschler arch has been added which controls this forced retropulsion.

Directions:

The main indication is secondary mandibular prognathism, particularly due to lingual antepulsion.

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Stop-type propellant activators:

They are distinguished by a propulsion device which mechanically guides the mandible by relying on the maxillary and mandibular dentoalveolar assemblies, either by resin bases or by fixed devices.

The connecting rods : They can be located:

– Vestibularly , between the upper and lower arches ( HERBST connecting rods on a gutter or on a fixed multi-attachment therapy).

Medially , between the plates: upper and lower (Connecting rods or propeller of MARTINE TAVERNIER

The JASPER JUMPER

Recently introduced into the world of orthodontics, it is a modification of the HERBST appliance. The rigid telescopic parts are replaced by elastic parts made of spiral-shaped springs covered with rubber. This elasticity allows chewing movements, particularly in the transverse direction.

Elastic or composite activators :

They have a mandible propulsion device which allows freedom of movement while guiding it, this is not the case for the rigid monobloc which gives a single bite reference.

a. FRANKEL device

Removable functional appliance called: “function regulator” which presents: A transpalatal arch.

A lingual shield with resin and buckles on the lingual surfaces of the incisors. Lateral vestibular shields.

Lip balls

A retro-incisal vestibular band

Allows passive expansion of the periosteal functional matrix thanks to the labial pads and the cheek screens placed at a distance (2 to 3 mm) from the alveolar processes which push back the musculature, promoting the effect of the tongue.

Mandibular advancement is ensured by the lingual screen which rests on the mandibular lingual mucosa.

soft activators:

Gugino and Yoshii thought of using the elastic properties of a material to build flexible devices from injected elastomer: polyvinyl silicone.

The device consists of a bimaxillary gutter whose construction is carried out from a therapeutic model which integrates the objectives of

orthopedic and/or orthodontic treatment, considered and defined by the practitioner for the patient concerned.

Mechanical orthopedics:

Uses active devices that directly modify the shape of the jaws (extrinsic forces).

The circuit breaker:

It is a fixed device , usable in the maxilla and allows rapid expansion of the maxilla by disjunction of the mid-palatal suture.

Slip ring circuit breakers:

Depending on their anchors, we distinguish:

The HAAS and HYRAX breaker which has 4 rings sealed on the 1st permanent molars and 1st premolars or 1st temporary molars.

The SCHEIDMAN 2-ring circuit breaker.

The recommended device consists of 4 rings adjusted on the first molars and the first premolars (14, 24, 16, 26) and secured by a large diameter jack (Hyrax).

Gutter circuit breaker:

It differs from the ring-mounted breaker by its gutters that cover the lateral sectors and are sealed directly onto the teeth. Note that on this device, hooks can be made and incorporated into the gutter to be able to attach elastics to a Delaire orthopedic mask.

Circuit breaker mode of action:

Opening of the intermaxillary suture further forward than backward and lower than upper and a slight advancement of point A.
Tilts the palatal plane downward and forward.

Activation :

A key attached to a long cord, to prevent it from being swallowed, making a quarter turn every 12 hours.

Three signs show the reality of the disjunction:

– appearance around the sixth day , a small diastema between the upper centrals,

A few days later, nasal breathing will appear.

-At the end of the month, a new vertical incidence image of Belot shows the separation of the right and left palatine blades.

Indications :

maxillary endognathism with respiratory disorders;
maxillary brachygnathia in class III, with endognathia.
In patients with horizontal or average growth.
sequelae of cleft lip and palate.

The quad helix:

This is a palatal arch designed by RICKETTS which has 4 internal loops, thus providing the necessary flexibility of action. It allows slow expansion with continuous and gentler forces than those of the expander (500g), it puts tension on the mid-palatal suture by stimulating its growth in patients under 12 years old.

It induces a more physiological adaptation of the sutural tissues and can be used in temporary, mixed or permanent dentition.
Indicated for maxillary endoalveolism associated or not with a laterodeviation,

It is made of round wire (0.36”) and has 4 helical loops (2 anterior and 2 posterior). It is welded to the anchor molar rings.

Activation takes place every 6 weeks :

Either by unsealing the rings for a new opening of the arms.
Either in the mouth using the 3-nose pliers , which will be applied to the central and lateral part of the device. This induces a disto-palatal rotation of the upper molars. We will look for an overcorrection: upper primary cusps in contact with the lower primary cusps; an overcorrection which will recur after removal.

The Bi-Helix

It is a lingual arch identical to the Quad-Helix but has only 2 loops according to its name. It allows expansion and correction of disorders

transverse to the lower arch.

Description: It is made of wire (0.36”)

its lateral arms must be applied to the premolars and canines, and be of equal lengths for better distribution of forces.
Its anterior part must be close to but not in contact with the lingual part of the incisal block.

Extraoral forces:

Extra-oral forces are devices whose common characteristic is to rest (anchor) on the craniofacial mass, thus allowing the movement of dento-skeletal elements without stressing the intra-oral anchorage and therefore without loss of anchorage or parasitic movements.

FEBs with anteroposterior traction:
FEB on rings:

It is a removable mechanical device. Allows heavy intermittent force to be applied, in an antero-posterior direction, to the molars without relying on the anterior teeth.

They are used either:

Cause a molar to move: Distalization Egression Ingression;
Anchoring: Holding the molar while other forces tend to move it
To act on the maxilla : by slowing down its antero-posterior growth.

Device Description:

Rings;
Face bow;
External anchoring (parietal, occipital, cervical);
Elastics (dynamic elements).

General Principles:
- Require excellent patient cooperation.
- Allow skeletal and dental modifications :
- The palatine plane version.
- Mandibular rotation in the direction of closing or opening the articulation (depending on the direction of traction).
- Modification of the occlusal plane, Distal movement of the teeth, Egression or intrusion).
- Reinforce the anchoring according to the mechanical needs of the treatment.
Effects of exo-oral forces on braces: At the level of the teeth

Four other movements are observed: translation version, egression, ingression, depending on the direction of traction (high, medium, low).

At the level of the maxilla:

The palatal plane (ENA-ENP) tilts, depending on the direction of traction.
The forward movement of the maxilla due to growth is significantly reduced. This action affects not only the molars but also the incisors and point A.

At the level of the mandible:

Molar egression in the case of low traction causes posterior rotation of the mandible.

Indications of FEB on rings:

Class II/1 Class II/2 Angle requiring molar or maxillary retraction.
Anchor reinforcement aid.
Contention.
- Contraindications of FEB:

Facial hyperdivergence.
Posterior crowding which would be aggravated by molar recession.
Lack of patient cooperation.
Concave profile.
Molar apex not closed.
FEB on gutter:

Definition:

These are OEMs whose internal arch is embedded in a gutter, encompassing the entire maxillary arch, it therefore allows an orthopedic force to be applied to

the entire maxillary arch.

AIM:

Applying extraoral forces to the dental arches, which are transmitted to the maxillary bone in order to slow the development of the upper jaw towards

forward and facilitate anterior rotation and forward movement of the mandible.

Effects:

Dental effects : ingression or egression movements occur in the vertical direction.

Linguoversion of the maxillary incisors

Distalization of the entire maxillary arch

Effects on the jaw

Depending on the orientation and length of the external branches, we will have:

a reduction/increase in incisal coverage.
a slight increase/decrease in posterior facial height.
Indications:

Class II division 1 without DDM with average or horizontal growth type, convex profile, average or reduced incisal coverage.

FEB on activator:

The main purpose of choosing the FEO activator combination is to better control the effects of the activator.

The occipital-mental slings:

Device Description
1. Cranial anchor element
2. Elastic element
3. Chin strap: prefabricated or made of resin and comprising 2 hooks.
Indications
Indicated in the early treatment of progression from 3 to 6 years

(discontinue after 6 months).

Early treatment of CL III due to mandibular prognathism.
Contention after correction.
Control of vertical growth of the face.

FEO with posterior-anterior traction:

a) The DELAIRE mask:

Description

Extraoral anchoring that rests on the forehead and chin. There are two types of masks: either frame (Delaire / Verdon) or medial rod (Petit).

Intraoral device : which can be:

A double arch sealed on the bands of the second temporary molars or the first permanent maxillary molars. Made of rigid wire (0.9) and includes hooks or coils at the distal level of the lateral incisor.
A splint encompassing the entire maxillary arch and comprising traction hooks included in the resin distal to the lateral incisors.
A circuit breaker: In cases where maxillary retrognathism is associated with endognathism.

Traction elastics:

Intensity: 600g to 800g according to Hickham.

-800g to 1500g according to Delaire.

The port: is 14 h/D.

Effects of face mask

Allows the anterior growth of the maxilla to be stimulated by stimulation of the maxillopalatine suture.

Base of the skull

-Increase in the anterior length of the base of the skull.

-Anterior and superior displacement of the nasion.

Maxillary

-Descent and advance from point A of

-A downward and forward movement of ENA, the palatal plane descends by 4mm.

-Increase in the length of the maxillary base ENA- ENP.

Mandible: Slowing of mandibular growth and posterior rotation of the mandible.

At the dental level:

-Anterior sliding of the upper alveolar arch on its bony base.

-Vestibulo-version of the upper incisors.

-a downward movement of the antero-superior occlusal plane a clockwise rotation.

Intermaxillary tractions:

Definition :

Intermaxillary tractions are intraoral aids consisting of elastic rings stretched between the two arches.

They come in different sizes and thicknesses, depending on the forces delivered, and are made of silicone, surgical latex, and rubber .

The force delivered is adjustable depending on their thickness and their

diameter as well as the duration of daily wear .

The force indicated by the manufacturer corresponds to the force delivered when the elastic is stretched three times its diameter.

Benefits :
- Put on and taken off by the patient
- – No cleaning, they are thrown away after wear
- – The intensity of their force increases through the movements of opening and closing the mouth.
- -No activation to be carried out by the orthodontist
Disadvantages:

Saliva reduces their elasticity and strength, so the force is not constant. After 2 hours in the mouth, the elastic force modulus decreases by nearly 30%.

The patient may hang them in the wrong way.

Indications and contraindications

Intermaxillary tractions are frequently used during orthodontic treatments:

to correct inter-arch relationships in the three dimensions of space;
to orient the mechanical effect of the arc and control its parasitic effects;
to perfect intercuspation in the finishing phases;
in post-surgical support.
Their main contraindication is linked to the egression movements of the anchor teeth and rotation of the arches which should make them avoided in hyperdivergent patients with posterior rotation of the mandible.
Caution and increased monitoring are recommended in subjects with joint disorders, especially when anteroposterior forces are exerted on the mandible.
The choice of latex-free elastics allows them to be prescribed for people with allergies.

Main types of intermaxillary traction
Oblique pull-ups:

Class II intermaxillary tractions :

Stretched from the posterior part of the mandibular arch to the anterior part of the maxillary arch and aimed at correcting a Class II occlusal discrepancy.

Effects of Class II TIMs:

Action on the maxillary arch:

-The upper arch moves back distally

-The upper incisors become more vertical

-All teeth are distalized. Action on the mandibular arch:

-The lower arch as a whole undergoes a mesial translation.

-The lower molar makes an occlusal extrusion with corono-mesial version.

-The lower incisors tilt vestibularly. Action on the facial pattern:

-The mandible rotates posteriorly

-The chin juts out

-Lower facial height increases with the intensity of force used and the duration of wearing the elastic.

Indications . These elastics are indicated in the treatment of class II:

for mass or sectoral recession of the maxillary arch,
to massively mesialize the mandibular arch or to lose posterior anchorage to the mandible,

contraindications;

Due to their vertical effect, they should be avoided in hyperdivergent subjects , those with a tendency towards posterior rotation and in patients with a gummy smile.

These intermaxillary tractions are also contraindicated in cases of

vestibuloversion of the mandibular incisors which they tend to aggravate.

Class III TIMs:

Are stretched from the anterior part of the mandibular arch to the

posterior of the maxillary arch .

Action of Class III TIMs:

Action on the maxillary arch:

-Advancement with mesial version and egression of the first molar

-Slight maxillary advancement.

– Vestibular version of the upper incisors Action on the mandibular arch:

-Distalization of the lower arch

-Extrusion of the lower incisors

-Lingual version of the lower incisors

Action on the facial schema:

-Posterior rotation of the mandible

-The chin goes down and back

-Lower facial height is increased

Indications and contraindications:

They are indicated in:

–– retraction of the mandibular incisors and correction of an anterior crossbite,

correction of a Class III occlusal by mass movement of both arches.

Besides the contraindications of TIMs depending on the vertical typology, the use of class III TIMs is contraindicated in cases of joint dysfunction .

Diagonal intermaxillary tractions:

Anchored on a maxillary canine and on the contralateral mandibular canine, they participate in the correction of asymmetries and particularly that of the shift of the incisor medians. They are responsible for a parasitic frontal tilt of the occlusal plane.

Crossed intermaxillary tractions:

These are elastics stretched from the lingual surface of one or more teeth to the vestibular surface of their antagonists to correct transverse relationships.

Most often, they join the palatal surface of a maxillary molar to the vestibular surface of a mandibular molar to correct a lateral crossbite. They can reinforce the action of expansion or contraction devices.

Vertical intermaxillary tractions:

Square, U, W and M shaped anterior elastics to close anterior gaps ;

Intercuspation elastics which can close lateral gaps but which are most often used to perfect the occlusion at the end of treatment