FIXED FUNCTIONAL APPLIANCES (PART 1) / dental implant courses by Indian dental academy

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FIXED FUNCTIONAL APPLIANCES(PART 1)

INDIAN DENTAL ACADEMYLEADER IN CONTINUING DENTAL EDUCATION


CONTENTS

Introduction Fixed Functional Appliances – An Overview Disadvantages Of Removable Appliances Advantages Of Fixed Functional Appliances

Over Removable Appliances Classification Of Fixed Functional Appliances Flexible Fixed Functional Appliances Rigid Fixed Functional Appliances Hybrid Appliances

www.indiandentalacademy.com Indications Contraindications Advantages Disadvantages A New Concept For Class II Therapy Timing Of Treatment – Ideal Treatment Period For Maximal

Mandibular Growth Stimulation. Skeletal Changes Associated With The Herbst Appliance

Based On Skeletal Maturation Mode Of Action Biomechanical Effects Of Fixed Functional Appliances On

Craniofacial Structures Herbst Appliance Therapy And Temporomandibular Joint

Disc Position Temporomandibular Joint Adaptations Associated With

Herbst Appliance Treatment. Effectiveness Of Treatment For Class Ii Malocclusion With

The Herbst Or Twin Block Appliance


INTRODUCTION


FIXED FUNCTIONAL APPLIANCES – AN OVERVIEW1


CLASSIFICATION OF FIXED FUNCTIONAL APPLIANCES2


Rigid Fixed functionals – ( ‘Herbst’ like) Flexible fixed functionals – (‘Jasper’

like) Hybrid appliances


RIGID FIXED FUNCTIONALS

Herbst and its modifications The Mandibular Anterior Repositioning splint (MARS) The Ventral Telescope The Magnetic telescopic device The Mandibular Protraction Appliance (MPA I – IV) The Biopedic appliance The Mandibular anterior repositioning appliance (MARA) The Intra-oral Snoring Therapy Appliance (IST) The Ritto Appliance The Universal Bite Jumper


FLEXIBLE FUNCTIONAL APPLIANCES

The Jasper Jumper Amoric Torsion Coils The Adjustable Bite Corrector, The Scandee Tubular Jumper, The Klapper Super Spring The Bite Fixer (Ormco) The Churro Jumper


HYBRID APPLIANCE

The Calibrated Force Module The Twin Force Bite Corrector Eureka Spring Forsus – Fatigue Resistant Device The Sabbagh Universal Spring


I) APPLIANCE PRODUCING PUSHING FORCE.

A) RIGID Herbst appliance MARS appliance [mandibular anterior

repositioning splint] MPA [Mandibular protraction appliance] Universal – bite jumper


B) FLEXIBLE Jasper jumper Adjustable bite corrector Churro jumper Klapper super spring II


II) Appliance producing pulling force. SAIF spring [Several adjustable

intermaxillary force spring].


FLEXIBLE FIXED FUNCTIONAL APPLIANCES1

What are they Supplied as Variations Advantages Elasticity & Flexibility CoveringHeadgear effect


Disadvantages:Elasticity & FlexibilityCovering Indications AestheticsInventoryExpensive Type of force Amount of force


Side effects Anchorage control


VARIOUS FLEXIBLE FIXED FUNCTIONAL APPLIANCES




Scandee tubular jumper


Klapper super spring


Bite fixer



Churro jumper


RIGID FIXED FUNCTIONAL APPLIANCES – RFFA1

Rigid Fixed functional appliances – RFFA1

They do not easily fracture but neither do they have elasticity or flexibility.

After fitting and activation they do not allow the patient to close in centric relation. This means that the mandible is in a forward position 24 hours a day creating greater stimulus for mandibular growth than with FFFAs.


Indication Telescopic mechanism


Herbst appliance – prototype


MAGNETIC TELESCOPIC DEVICE


MANDIBULAR PROTRACTION APPLIANCE (MPA) (FILHO‘S APPLIANCE)


THE UNIVERSAL BITE JUMPER (UBJ)


THE MANDIBULAR ANTERIOR REPOSITIONING APPLIANCE (MARA)


BIOPEDIC APPLIANCE


RITTO APPLAINCE


HYBRID APPLIANCES1

What are they.CALIBRATED FORCE MODULE

www.indiandentalacademy.comEUREKA SPRING


TWIN FORCE BITE CORRECTOR


FORSUS


INDICATIONS

The fixed functional appliances are indicated in correction of skeletal Class II malocclusions due to retrognathic mandible.(including div1 & div 2).

Post adolescent patients Possible to use residual growth left in these

patients as treatment completed in 6-8 months. Mouth breathers Uncooperative patients Patients who do not respond to removable

functional appliances.


CONTRAINDICATIONS

Contraindicated in non-growing patients.

Hyperdivergent facial pattern. A patient with negative VTOUse of functional appliances results in

less than satisfactory results and is therefore not recommended.


ADVANTAGES

Used in uncooperative patient. i.e. patients compliance not required.

Action is continuous for 24 hours of the day. Achieve the results in around 6-8 months. Advantageous in mouth breathers. Does not interfere with speech or mastication. Used successfully in post adolescent patients in

whom very little growth is remaining to work with. Procedures such as rapid maxillary expansion,

fixed appliance or head gear can be given with appliance in place.


DISADVANTAGES

Though treatment result can achieved within 6-8 months, retention of the result has to be maintained using removable functional appliance.

Risk of development of dual bite. Masticatory efficiency may be reduced. High incidence of breakage and loosening of

the appliance. May restrict lateral mandibular movements. Plaque accumulation and enamel

decalcification may occur, especially in the splint type of appliance.


TIMING OF TREATMENT


THE IDEAL TREATMENT PERIOD FOR MAXIMALMANDIBULAR GROWTH STIMULATION

Subjects treated at peak or 1 to 2 years after peak exhibited the largest sagittal condylar growth and thus the largest mandibular length increase.

Correspondingly, the greatest amount of sagittal condylar growth was found in subjects treated at the skeletal maturity stage MP3-FG, which occurs close to the peak growth period .


Showed a steady increase in sagittal condylar growth stimulation from the prepeak to the peak growth period, followed by a steady decline in the postpeak period.

This pattern was most obvious in boys, whereas in girls no marked differences in skeletal mandibular treatment effects were found when comparing different growth periods.


It is believed that Class II correction by orthopaedic means is not possible after the age of 13.5 years in girls and 15 years in boys because 97% of the growth is completed at these ages.

However,in using the Herbst appliance, it is possible to reactivate and stimulate condylar growth even in subjects at the end of growth.


The IDEAL PERIOD for the Herbst appliance is in the permanent dentition at or just after the pubertal peak of growth corresponding to the skeletal maturity stages FG to H of the middle phalanx of the third finger.

www.indiandentalacademy.comSKELETAL CHANGES ASSOCIATED WITH THE

HERBST APPLIANCE BASED ON SKELETALMATURATION

Objective: To evaluate skeletal changes when the

Herbst appliance is used in patients during the high-velocity and the decelerating-velocity periods of adolescent growth.

To chart differences(if any) in the amounts of skeletal and dental changes with the Herbst appliance in relation to the maturation stage of development.


METHOD In group 1 (n =19), the subjects were in

the high-velocity period of adolescent growth when treatment with Herbst appliances was started;

In group 2 (n = 21), they were in the decelerating period of adolescent growth.

Cephalograms were evaluated at pretreatment and posttreatment.


RESULTS AND CONCLUSIONS Although there were small differences

between the 2 groups, these were not statistically significant. The Herbst appliance was equally effective when used at the high-velocity and the decelerating-velocity periods of adolescent growth.


A NEW CONCEPT FOR CLASS II THERAPY

The current and widely accepted concept of skeletal Class II treatment is

(1) growth modification(with functional appliances and/or headgear)in prepeak and peak patients,

(2) camouflage orthodontics (extractions of teeth and fixed appliances) in postpeak patients, and

(3)orthognathic surgery in adults


The new concept of Class II treatment proposes the following:

(1) growth modification in children and adolescents as well as in postadolescents and young adults (up to the age of 25 years),

(2) camouflage orthodontics, and (3)orthognathic surgery in older adults. Growth modification in children should be

performed with removable functional appliances and/or headgear.

In adolescents, postadolescents and young adults the Herbst appliance should be used.


MODE OF ACTION

Mandibular growth induction. Maxillary growth restriction Dentoalveolar changes Glenoid fossa relocation Changes in neuromuscular anatomy

and function.


Functional appliance

Increased contractile activity of LPM

Intensification of retrodiscal pad activity

Increase in growth stimulating factors

Additional growth of condylar cartilage and subperiosteal ossification of posterior border of ramus.

Supplementary lengthening of mandible

www.indiandentalacademy.comBIOMECHANICAL EFFECTS OF FIXED FUNCTIONAL APPLIANCES ON CRANIOFACIAL STRUCTURES

Objective: To evaluate displacement and stress distribution on craniofacial structures associated with fixed functional therapy.

Materials and Methods: A finite element model of the human skull was constructed from computed tomography images.




Results: The entire mandible moved anteroinferiorly The pterygoid plate was displaced in a posterosuperior direction. The anteroinferior displacement of the mandibular dentition was

most pronounced in the incisor region. The maxillary dentition was displaced posterosuperiorly. The entire dentition experienced tensile stress except for the

maxillary posterior teeth. Tensile stress was also demonstrated at point A, the pterygoid

plates, and the mandible, and minimal compressive stress was demonstrated at anterior nasal spine.

Maximum tensile stress and von Mises stresses occurred in the condylar neck and head.


Conclusion: Fixed functional therapy causes a posterosuperior displacement of the maxillary dentition and pterygoid plate and thus can contribute to the correction of Class II malocclusion.

The displacement was more pronounced in the dentoalveolar region as compared to the skeletal displacement.

All dentoalveolar structures experienced tensile stress, except for anterior nasal spine and the maxillary posterior teeth

www.indiandentalacademy.comHERBST APPLIANCE THERAPY AND TEMPORO MANDIBULAR JOINT DISC POSITION:A PROSPECTIVE LONGITUDINAL MAGNETIC

RESONANCE IMAGING STUDY

The objective of this study was to verify changes in the position of the temporo mandibular joint (TMJ) disc by means of magnetic resonance images (MRIs) in adolescent patients treated with the Herbst appliance.

Method: Twenty Class II Division 1 patients treated with Herbst appliances were selected for the study. MRIs were analyzed at 3 stages: immediately before Herbst treatment (T1), 8 to 10 weeks after appliance placement (T2), and at the end of the 12-month Herbst treatment, immediately after appliance removal (T3).


Results: Class I or overcorrected Class I dental-arch relationships were observed after Herbst therapy.

The qualitative evaluation showed that each patient had the disc within normal limits at T1. At T2, a slight tendency toward disc retrusion because of mandibular advancement was observed, but,

at T3, the disc returned to normal, similar to T1 values


MRIs of treated TMJs in closed mouth position. Top row, right; Bottom row, left. Articular disc is in superior normal position at T1 and T3, with retrusive tendency at T2.

www.indiandentalacademy.comEFFECTIVENESS OF TREATMENT FOR CLASS IIMALOCCLUSION WITH THE HERBST OR TWIN-BLOCK APPLIANCES:

A RANDOMIZED, CONTROLLED TRIAL

A total of 215 patients were enrolled in the study:

110(62 girls and 48 boys) were allocated to receive treatment with the Twin-block, and 105 (55 girls and 50 boys) to the Herbst group.

The patient inclusion criteria for this investigation were overjet 7 mm, second premolars erupted, and no craniofacial syndrome.


CONCLUSIONS

1. Patient cooperation with the Herbst appliance is better

than that with the Twin-block.2. Phase I treatment is more rapid with the Herbst

appliance, but overall duration of treatment is similar to that with the Twin-block.

3. The Herbst appliance is prone to debonding and component breakage.

4. There are no differences in the dental and skeletal effects of treatment between the 2 appliances, but there was a marked sex effect: girls responded to treatment better than boys.


REFERENCES

1. A Korrodi Ritto. Fixed Functional Appliances - A Classification. Orthodontic Cyber Journal .2001;4:1- 38.

2. Poppadipolus. The Orthodontic Treatment Of Class II Non-Compliant Patient,2nd ed.Elsevier;2001:145-160.

3. Graber,Petrovic,Rakosi.Dentofacial Orthopaedics With Functional Appliances,2nd edtion. Mosby; 1997:360-365.

4. P.F Mcsherry.Class II Correction- Reducing Patient Compliance.Journal Of Orthodontics.2000;27:219-225.

5. Sabine Ruf And Hans Pancherz.When Is The Ideal Period For Herbst Therapy-Early Or Late?. Semin Orthod. 2003;9:47-56.


REFERENCES J. Godinho And L. Fishman.Skeletal Changes Associated With The

Herbst Appliance Based On Skeletal Maturation. Am J Orthod Dentofacial Orthop.2007;132:128-136.

Carlos Flores-Mir.Skeletal And Dental Changes In Class IIDivision 1 Malocclusions Treated With Splint-Type Herbst Appliances-A Systematic Review.Angle Orthodontist.2007;77:34-42.

Luís Antônio De Arruda Aidar.Herbst Appliance Therapy And Temporomandibular Joint Disc Position-A Prospective Longitudinal Magnetic Resonance Imaging Study.Am J Orthod Dentofacial Orthop. 2006;129:486-96.

John E. Peterson, Jr, And James A. Mcnamara, Jr. Temporo Mandibular Joint Adaptations Associated With Herbst Appliance Treatment In Juvenile Rhesus Monkeys (Macaca Mulatta). Semin Orthod. 2003;9:12-25.

Abbie T. Schaefer, DDS, MS,A James A. Mcnamara.A Cephalometric Comparison Of Treatment With The Twin-Block And Stainless Steel Crown Herbst Appliances Followed By Fixed Appliance Therapy.Am J Orthod Dentofacial Orthop.2004;126:7-15.

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FIXED FUNCTIONAL APPLIANCES (PART 1) / dental implant courses by Indian dental academy