expansion in orthodontics /certified fixed orthodontic courses by indian dental academy

EXPANSIONEXPANSION

INDIAN DENTAL ACADEMY

Leader in continuing dental education www.indiandentalacademy.com

www.indiandentalacademy.com

Topics :-

Classification

History Of Expansion

Arch Width Changes (Physiologic)

Anatomy Of Maxilla and Mandible

Histology Of Suture and Symphysis

Stresses generated during Transverse Expansionwww.indiandentalacademy.com

Expansion

Transverse Antero-posterior

DentalSkeletalwww.indiandentalacademy.com

ANATOMY ANDHISTOLOGY


Symphysis joint(Grays Anatomy)


Symphysis joint

Symphysis menti

(Atlas Oral AnatomyHolland G R)


Symphysis joint(Grays Anatomy)www.indiandentalacademy.com

Bone

Fibrocartilage

Collagen Fibres


Maxilla and its Articulations(Grays Anatomy)


American Journal Of Dentofacial Orthopedics 1987;91)www.indiandentalacademy.com

Midpalatal suture


Zone Of Intense Proliferationwww.indiandentalacademy.com

A-P Direction Of Collagen Fibreswww.indiandentalacademy.com

Transversely oriented collagen fibreswww.indiandentalacademy.com

Network Of Collagen Fibres In centre Of Suturewww.indiandentalacademy.com

s


Sharpey fibres


T

BS

TRANSITIONAL SPACEwww.indiandentalacademy.com

SINUOUS AND IMBRICATING NATURE OF SUTUREwww.indiandentalacademy.com

NARROWED ZONE OF CELLULAR PROLIFERATIONwww.indiandentalacademy.com

S


LIGHT MICROSCOPIC VIEWwww.indiandentalacademy.com

ELECTRON MICROSCOPIC VIEWwww.indiandentalacademy.com

HISTORY(The Angle Orthodontist1999;69)(Rapid Maxillary Expansion;Timms)


Sir Emerson C Angellwww.indiandentalacademy.com

San Francisco Medical Press 1860

*14 year old girl patient with ectopic left upper lateral and premolar.

*Importance of first permanent molars.

Dental Cosmos


Expansion appliance:-Dr Angell

Note Diastema


Appliance with contrarotating screw

Gold


We must beg leave to differ with the author inthe conclusion arrived at,that by the use of apparatus described he succeeded in separating the superior maxilla from each other.With no disposition to assert that such a thing is utterly impossible,yet,when taking into consideration theanatomical relations existing between the two halves of maxilla and other bones with which they articulatesuch a result appears exceedingly doubtful.

(J.DeH.White)


As shown in Dental Cosmos


ARCH WIDTH CHANGES(American journal Of Dentofacial Orthopedics1997;111)(T.M.Graber;Orthodontics –Practise and Principles)


Study Of Stress Distribution and Displacement Of Various Craniofacial Structures Following Application Of Transverse Orthopedic Forces:-

FEM Study

(The Angle Orthodontist2002;73)(American Journal Of Dentofacial Orthopedics 1987;91)


1www.indiandentalacademy.com

Conclusions:-

•Maximum lateral displacement was 5.313mm at node 12911.

•Pyramidal displacement of the maxilla was visible from the front view.

•The width Of the nasal cavity increased markedly.The inferior parts of the pterygoid plates were markedly displaced or bent laterally,but minimal displacement was observed in the region close to cranial base.


•Maximum negative Y-displacement(backward displacement)was 1.1599 at node 2314 corresponding to the posterior rim of the frontalprocess of the zygomatic bone.

•Maximum positive Y-displacement(forward displacement) was 1.077 at node6022,which represents the anteroinferior border of the nasal septum.


•Maximum negative Z displacement(downwarddisplacement was 1.22 at node52,which represents theposterior most portion of the nasal septum.

•Maximum positive Z displacement(upward displacement)1.758mm at node241 which represents body of the zygomatic bone.

•Thus the nasomaxillary complex rotated such that the lateral structures had moved upwards and midline structures downwards.

•The anterior part of maxillary bone(point A)were displaced downwards.


Topics:

Rapid Palatal Expansion

Slow Palatal Expansion


Expansion

Skeletal Dental

Transverse Anteroposterior

SlowSemi rapidRapidUltra rapid


Indications Of Rapid Palatal Expansion:-

Occlusion -Full cusp crossbite with skeletal component. -Some degree of dental as well as skeletal component. -No open bite tendency. -No preexisting dental expansion.

Respiration -Poor nasal airway -Septal deformity -Recurrent nasal ,sinus infection -Asthama


Hazards Of RME:-

Oral Hygiene

Dislodgment and breakage

Tissue damage

Infection(Acute ulcerative gingivitis)

Failure of suture to open


(a) Derichsweiler type Tags are welded and soldered to the palatal aspects of the bands to provide attachments for the acrylic which is also extended to the palatal aspects of all non banded teeth except the insicors.‑


(b) Haas type A length of .045 in (1 .15 mm) stainless steel wire is welded and soldered along the palatal aspects of the bands The free ends are turned backand embedded into the acrylic base.A proprietary srew is set in the midline of the acrylic split.


Haaswww.indiandentalacademy.com

(c) lsaacson type This appliance uses a special spring loaded screw called a Minne. Expander which is adapted and soldered direct to the bands without the use of acrylic, The screw may be reduced in length to suit narrow arches by shortening the spring, tube and rod.


(d)Biedermann type This appliance also required a special screw, either Hyrax (Dentaurum 602 813). Leone 620 or Unitek ‑440 160, These have extensions in heavy gauge wire ‑which are welded and soldered to the palatal aspects of the bands


Hyrax Screw


Forestadent Screw


Activation:-180º rotation /day(Ziebe)

Upto Age 15 years -90º both morning and evening.

Age 15-20 years -45º turns 4 times a day

Age over 20 years - Same as above or 45º in the morning and 90º at night


In general,bony spicules appear at the age of 15 and 19 years(0.9% fo suture length),but these bridges may be removed by osteoclast to suit physiologic requirements.

A greater degree of obliteration occurs posteriorlythan anteriorly.

On average 5% of suture is closed by age 25.

(By Persson et al 1977)


Age and prognosis:

Age 7 to 15:Good

Age 15 to 20:Good although recall every other dayTo check opening of suture.

Age 20 to 30:Possible but daily recall necessary,Danger that the suture does not open and there is overloading of the posterior segment,ulceration of mucosa.


Treatment timing for rapid maxillary expansion(Angle orthodontist;2001)

The group treated before the pubertal peak,in the long term,showed significantly greater maxillary skeletalWidth,maxillary intermolar width,lateronasal width andLateroorbital width

The late treated group exhibited significant increase in Maxillary and mandibular intermolar width.(thus moreDentoalveolar than skeletal)


According to Mayoral and Aristeguinta


Slow Expansion Rapid Expansionwww.indiandentalacademy.com

Maxillary Expansion by Hass(AJO;Vol 57,No8,1970)


*Correction of mouth breathing.*Improvement of concentration.*Mouthbreathing not influenced.*Some improvement of nasal breathing www.indiandentalacademy.com

Slow Expansion


Schwarz Appliancewww.indiandentalacademy.com

Crozat Appliance


Fan Appliancewww.indiandentalacademy.com

Wipla-type Forestadent screw


Bar type-Two way expansion screw


The Nardella eccentric expansion screw


Quad Helix

Ricketts


3 D Multiaction palatal appliance


3D Quad Helix palatal Appliance(Wilson)


Sagittal I Appliance


Sagittal II Appliancewww.indiandentalacademy.com

Ultra-Rapid Expansion

•By Chaure….3mm of expansion was achieved in one and half hour.

•Three visits.

•Anaesthesia is administered.

•Used by E.N.T. surgeons then.


NiTi GROUP RPE GROUP

Measurement

Mean Standard Deviation

Mean Standard Deviation

PWC(mm)

0.99 0.45 1.41 1.09

IMWC(mm)

6.26 1.65 4.76 1.55

RATIO PWC/IMWC

0.16 0.08 0.28 0.17

PWC=palatal width change; IMWC=intermolar width change; PDC=palatal depth change; AT=alveolar tipping; MR=molar rotation; MT=molar tipping


RATIO PWC/IMWC

0.16 0.08 0.28 0.17

AT(degrees)

6.61 3.73 5.08 5.43

PDC(mm)

-0.04 0.70 -0.07 0.89

MR(degrees)

26.61 16.29 1.58 2.74


MR(degrees)

26.61 16.29 1.58 2.74

MT(degrees)

11.69 10.47 6.08 6.25


The NiTi transpalatal loops has a transition temperature of 94oF. The martensitic transformation and superelastic properties of the NiTi wires helped the insertion of the expander into the lingual sheaths of prefitted maxillary molar bands. Expansion occurs after insertion when the appliance was warmed up to body temperature and the NiTi loops return to its original shape. Over expansion was built into the treatment to anticipate relapse (approximately 30%) due to uprighting of the maxillary molars after removal of appliance.


NiTi transpalatal loops were sprayed with tetrafluoroethane refrigerant prior to placement of the appliance.


Original Pendulum design

.032” TMA

NanceButtonOcclusal

rests


Pendexwww.indiandentalacademy.com

T-Rex Design

Mesial wire


The PHD Appliance

Pendulum Hygiene Design/devicewww.indiandentalacademy.com


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expansion in orthodontics /certified fixed orthodontic courses by indian dental academy

Documents

symphysis joint grays

dental cosmos

symphysis stresses

network of collagen

oriented collagen fibres

articulations grays

expansion appliance

halves of maxilla