GOOD MORNINGGOOD MORNING
INDIAN DENTAL ACADEMY
Leader in continuing dental education
www.indiandentalacademy.com
www.india...
MAGNETIC RETENTIONMAGNETIC RETENTION
IN MAXILLO FACIALIN MAXILLO FACIAL
PROSTHESESPROSTHESES
www.indiandentalacademy.com
INTRODUCTIONINTRODUCTION
www.indiandentalacademy.com
 The success of most extra oral prosthesesThe success of most extra oral prostheses
depends on retention.depends on reten...
 A number of methods of retention are available.A number of methods of retention are available.
These include :-These inc...
 The use of magnets has been popular inThe use of magnets has been popular in
dentistry.dentistry.
 The reason of popula...
 Javid, in 1971 constructed an extensiveJavid, in 1971 constructed an extensive
prostheses for both extra-oral and intra-...
HISTORYHISTORY
www.indiandentalacademy.com
 Magnets were first introduced for applications inMagnets were first introduced for applications in
dentistry in 1953 in ...
 One of the earliest magnets was pairedOne of the earliest magnets was paired
AlnicoAlnico which is a permanent magnet al...
 In late 1960s another permanent magnet inIn late 1960s another permanent magnet in
which cobalt was alloyed with Samariu...
 Another alloy based on neodymium – iron –Another alloy based on neodymium – iron –
boron became available in 1980s for d...
CLASSIFICATIONCLASSIFICATION
www.indiandentalacademy.com
 Based on alloys usedBased on alloys used
• Those containing cobalt.Those containing cobalt.
E.g. Alnico, Alnico V, Co-Pt...
 Based on surface coatingBased on surface coating
• CoatedCoated
• UncoatedUncoated

Based on the type of magnetismBased...
 Based on number of magnets in theBased on number of magnets in the
systemsystem
 SingleSingle
 PairedPaired
 Based on...
MECHANISM OF MAGNETISMMECHANISM OF MAGNETISM
 Every atom in a material is a magnet becauseEvery atom in a material is a m...
 On application of a magnetic field, these domainsOn application of a magnetic field, these domains
align to reach a satu...
MAGNETIC MATERIALSMAGNETIC MATERIALS
Over the last century, significant advances have madeOver the last century, significa...
 The main magnetic material used isThe main magnetic material used is
the rare earth materialthe rare earth material Neod...
 Samarium Cobalt (SmCo) magnets: ofSamarium Cobalt (SmCo) magnets: of
the Rare Earth class, have been availablethe Rare E...
Alnico-alloysAlnico-alloys
 The Aluminum/Nickel/CobaltThe Aluminum/Nickel/Cobalt
combination is excellent for highcombina...
 Samarium iron nitride is a promising newSamarium iron nitride is a promising new
material for permanent magnet applicati...
Design of Magnetic Attachments.Design of Magnetic Attachments.
Magnet systems may be either anMagnet systems may be either...
 An open field system consistsAn open field system consists
of a cylindrical magnet withof a cylindrical magnet with
open...
 In closed field system Consists ofIn closed field system Consists of
paired magnets and an attachable andpaired magnets ...
 Attachment of closed-field magnets is moreAttachment of closed-field magnets is more
efficient because both the north an...
 A small magnetic field is attached to the top ofA small magnetic field is attached to the top of
the magnets.the magnets...
 A reversed split pole system was designed byA reversed split pole system was designed by
Gillings, provided a greater fo...
 Finite element analysis has been used to the design ofFinite element analysis has been used to the design of
attachments...
www.indiandentalacademy.com
www.indiandentalacademy.com
ADVANTAGESADVANTAGES
 Ease of placementEase of placement
 Automatic reseatingAutomatic reseating
 Constant retention wi...
DISADVANTAGESDISADVANTAGES
 Low corrosion resistanceLow corrosion resistance
 Cytotoxic effectsCytotoxic effects
 High ...
MAGNETIC RETENTIONMAGNETIC RETENTION
 Application of magnetic force in retention ofApplication of magnetic force in reten...
MAGNETIC RETENTION IN DIFFERENTMAGNETIC RETENTION IN DIFFERENT
MAXILLO FACIAL PROSTHESESMAXILLO FACIAL PROSTHESES
 EXTRA ...
 Intra oral prostheses-Intra oral prostheses-
 ObturatorsObturators
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FREESTANDING MAGNETIC RETENTION FORFREESTANDING MAGNETIC RETENTION FOR
EXTRAORAL PROSTHESES WITHEXTRAORAL PROSTHESES WITH
...
 The most common method of retentionThe most common method of retention
used in conjunction with implants is theused in c...
 The use of magnets inThe use of magnets in
conjunction with a bar splint orconjunction with a bar splint or
as a complet...
 It is important to be selective in the use of freestandingIt is important to be selective in the use of freestanding
mag...
www.indiandentalacademy.com
RETENTION OF MAGNETS IN ENDOSTEALRETENTION OF MAGNETS IN ENDOSTEAL
IMPLANTS USED FOR FACIAL PROSTHESESIMPLANTS USED FOR FA...
 At present, endosteal implants andAt present, endosteal implants and
implant-supported epitheses are the stateimplant-su...
www.indiandentalacademy.com

 End osseous Fixtures in the Calotte used for retaining
Wigs With magnetic attachments

www.indiandentalacademy.com
Magnetic retention in midfacialMagnetic retention in midfacial
prostheses without implants.prostheses without implants.
ww...
www.indiandentalacademy.com
MAGNETIC RETENTION IN AURICULAR PROSTHESES
www.indiandentalacademy.com
MAGNETIC RETENTION INMAGNETIC RETENTION IN
COMBINED PROSTHESESCOMBINED PROSTHESES
www.indiandentalacademy.com
www.indiandentalacademy.com
 Intra-oral magnetic retentionIntra-oral magnetic retention
The hollow facial epithese was made with medical silicone mat...
CONCLUSIONCONCLUSION
 Magnets have been effectively used for theMagnets have been effectively used for the
retention, mai...
Thank you
For more details please visit
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Magnetic retention in maxillo facial prostheses/ General orthodontics

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Magnetic retention in maxillo facial prostheses/ General orthodontics

  1. 1. GOOD MORNINGGOOD MORNING INDIAN DENTAL ACADEMY Leader in continuing dental education www.indiandentalacademy.com www.indiandentalacademy.com
  2. 2. MAGNETIC RETENTIONMAGNETIC RETENTION IN MAXILLO FACIALIN MAXILLO FACIAL PROSTHESESPROSTHESES www.indiandentalacademy.com
  3. 3. INTRODUCTIONINTRODUCTION www.indiandentalacademy.com
  4. 4.  The success of most extra oral prosthesesThe success of most extra oral prostheses depends on retention.depends on retention.  The problem of retention in maxillofacialThe problem of retention in maxillofacial prosthesis is a great challenge posed to theprosthesis is a great challenge posed to the prosthodontists.prosthodontists.  When the prosthesis is designed, fullWhen the prosthesis is designed, full consideration must be given to the retention ofconsideration must be given to the retention of the prosthesis.the prosthesis. www.indiandentalacademy.com
  5. 5.  A number of methods of retention are available.A number of methods of retention are available. These include :-These include :-  Mechanical devicesMechanical devices  Anatomic methods andAnatomic methods and  Adhesives with or without the use of the otherAdhesives with or without the use of the other methods.methods.  The mechanical retention methods includes theThe mechanical retention methods includes the use of magnets amongst many other methods.use of magnets amongst many other methods. www.indiandentalacademy.com
  6. 6.  The use of magnets has been popular inThe use of magnets has been popular in dentistry.dentistry.  The reason of popularity is related to theirThe reason of popularity is related to their small size and strong attractive forces.small size and strong attractive forces.  Magnets have generated great interest inMagnets have generated great interest in dentistry, and their application are numerous.dentistry, and their application are numerous.  They are being used as retentive aids for overThey are being used as retentive aids for over dentures, removable partial dentures anddentures, removable partial dentures and implants.implants. www.indiandentalacademy.com
  7. 7.  Javid, in 1971 constructed an extensiveJavid, in 1971 constructed an extensive prostheses for both extra-oral and intra-oralprostheses for both extra-oral and intra-oral aspects connected with magnets.aspects connected with magnets.  Federick, in 1976, rehabilitated a patientFederick, in 1976, rehabilitated a patient with a large orofacial defect using a 2-with a large orofacial defect using a 2- component obturator that was locked tocomponent obturator that was locked to In maxillofacial prosthodontics theyIn maxillofacial prosthodontics they have been used for decades tohave been used for decades to reconstruct large defects with the helpreconstruct large defects with the help of multiple component prostheses.of multiple component prostheses. www.indiandentalacademy.com
  8. 8. HISTORYHISTORY www.indiandentalacademy.com
  9. 9.  Magnets were first introduced for applications inMagnets were first introduced for applications in dentistry in 1953 in the field of orthodontics.dentistry in 1953 in the field of orthodontics.  Conventional magnets were applied inConventional magnets were applied in prosthodontics in the year 1960 as retentiveprosthodontics in the year 1960 as retentive devices for over dentures, removable partialdevices for over dentures, removable partial dentures and maxillo- facial prostheses.dentures and maxillo- facial prostheses. www.indiandentalacademy.com
  10. 10.  One of the earliest magnets was pairedOne of the earliest magnets was paired AlnicoAlnico which is a permanent magnet alloy ofwhich is a permanent magnet alloy of iron, cobalt ,nickel and aluminum. But theiron, cobalt ,nickel and aluminum. But the main disadvantage of this system was themain disadvantage of this system was the large size.large size.  Coated and uncoated cobalt-platinum barCoated and uncoated cobalt-platinum bar magnets(co-pt) were implanted in themagnets(co-pt) were implanted in the mandible by Behr man and Toto to retain amandible by Behr man and Toto to retain a denture.denture. www.indiandentalacademy.com
  11. 11.  In late 1960s another permanent magnet inIn late 1960s another permanent magnet in which cobalt was alloyed with Samariumwhich cobalt was alloyed with Samarium (Co(Co55sm) was introduced, it has twice thesm) was introduced, it has twice the magnetic field strength of co-pt and themagnetic field strength of co-pt and the strongest of Alnico alloys.strongest of Alnico alloys.  These magnets could be produced in veryThese magnets could be produced in very small dimensions and approximately one fifthsmall dimensions and approximately one fifth of Co-pt magnets and still could provide sameof Co-pt magnets and still could provide same force.force. www.indiandentalacademy.com
  12. 12.  Another alloy based on neodymium – iron –Another alloy based on neodymium – iron – boron became available in 1980s for dentalboron became available in 1980s for dental applications. Both Coapplications. Both Co55Sm and Nd-Fe-B areSm and Nd-Fe-B are termed as rare earth magnets because they aretermed as rare earth magnets because they are rare from the standpoint of extraction.rare from the standpoint of extraction.  Another material Samarium iron nitride is beingAnother material Samarium iron nitride is being developed for medical and dental appliances. Itdeveloped for medical and dental appliances. It is highly resistant to demagnetization and hasis highly resistant to demagnetization and has better resistance to temperature and corrosionbetter resistance to temperature and corrosion than Nd-Fe-B. It is still under development.than Nd-Fe-B. It is still under development. www.indiandentalacademy.com
  13. 13. CLASSIFICATIONCLASSIFICATION www.indiandentalacademy.com
  14. 14.  Based on alloys usedBased on alloys used • Those containing cobalt.Those containing cobalt. E.g. Alnico, Alnico V, Co-Pt.E.g. Alnico, Alnico V, Co-Pt. • Those not containing cobalt.Those not containing cobalt. E.g. Nd-Fe-B, Samarium iron nitride.E.g. Nd-Fe-B, Samarium iron nitride.  Based on ability to retain magnetic propertiesBased on ability to retain magnetic properties • Soft (Easy to magnetize or demagnetize – less permanent).Soft (Easy to magnetize or demagnetize – less permanent). E.g. Pd-Co-Ni alloy, Pd-Co alloyE.g. Pd-Co-Ni alloy, Pd-Co alloy • Hard (Retain magnetism permanently).Hard (Retain magnetism permanently). E.g. Alnico alloy, Co-Pt.E.g. Alnico alloy, Co-Pt. www.indiandentalacademy.com
  15. 15.  Based on surface coatingBased on surface coating • CoatedCoated • UncoatedUncoated  Based on the type of magnetismBased on the type of magnetism • RepulsionRepulsion • AttractionAttraction  Based on the type of magnetic fieldBased on the type of magnetic field • Open fieldOpen field • Closed fieldClosed field  Rectangular closed – field sandwich designRectangular closed – field sandwich design  Circular closed – field sandwich designCircular closed – field sandwich design www.indiandentalacademy.com
  16. 16.  Based on number of magnets in theBased on number of magnets in the systemsystem  SingleSingle  PairedPaired  Based on the arrangement of polesBased on the arrangement of poles  Reversed polesReversed poles  Non-reversed polesNon-reversed poles www.indiandentalacademy.com
  17. 17. MECHANISM OF MAGNETISMMECHANISM OF MAGNETISM  Every atom in a material is a magnet becauseEvery atom in a material is a magnet because electrons orbit it’s nucleus. While theseelectrons orbit it’s nucleus. While these electrons move they produce a magnetic fieldelectrons move they produce a magnetic field around the atom.around the atom.  In some atoms such as Fe, Ni, and Co, thereIn some atoms such as Fe, Ni, and Co, there are unpaired electrons that create a tinyare unpaired electrons that create a tiny magnetic field.magnetic field.  In a magnetic material, a large portion of theseIn a magnetic material, a large portion of these atoms align in small regions called “domains”.atoms align in small regions called “domains”. www.indiandentalacademy.com
  18. 18.  On application of a magnetic field, these domainsOn application of a magnetic field, these domains align to reach a saturation point, at this point thealign to reach a saturation point, at this point the material is magnetized.material is magnetized.  Some materials require small magnetic field to reachSome materials require small magnetic field to reach the saturation point called “the saturation point called “softsoft” magnet, some” magnet, some require larger magnetic field to be magnetized, suchrequire larger magnetic field to be magnetized, such material becomes a “material becomes a “hardhard”” magnet.magnet.  When the external magnetic field is removed, if theWhen the external magnetic field is removed, if the material retains its magnetization then it is called amaterial retains its magnetization then it is called a permanent magnetpermanent magnet.. www.indiandentalacademy.com
  19. 19. MAGNETIC MATERIALSMAGNETIC MATERIALS Over the last century, significant advances have madeOver the last century, significant advances have made in the development of magnetic materials. Thesein the development of magnetic materials. These advances have been quickly transferred into dentaladvances have been quickly transferred into dental applications.applications.  NeodymiumNeodymium –– iron boroniron boron––(Nd-Fe-B)(Nd-Fe-B)  RE-alloy samarium cobalt.RE-alloy samarium cobalt.  Alnico-alloysAlnico-alloys  Samarium iron nitrideSamarium iron nitride www.indiandentalacademy.com
  20. 20.  The main magnetic material used isThe main magnetic material used is the rare earth materialthe rare earth material NeodymiumNeodymium – iron boron–(Nd-Fe-B)– iron boron–(Nd-Fe-B)  It is the most powerful commerciallyIt is the most powerful commercially available magnetic material.available magnetic material.  This group of magnetic materialsThis group of magnetic materials provides the highest availableprovides the highest available magnetic energies of any material.magnetic energies of any material.  NdFeB magnets allow small shapesNdFeB magnets allow small shapes and sizes with high magnetic fields.and sizes with high magnetic fields.  Coating is needed for NdFeBCoating is needed for NdFeB Neodymium – iron boron www.indiandentalacademy.com
  21. 21.  Samarium Cobalt (SmCo) magnets: ofSamarium Cobalt (SmCo) magnets: of the Rare Earth class, have been availablethe Rare Earth class, have been available since the early 1970's.since the early 1970's.  These magnets possess very highThese magnets possess very high magnetic properties, excellent thermalmagnetic properties, excellent thermal stability, and remarkable resistancestability, and remarkable resistance against corrosion and oxidation.against corrosion and oxidation.  These characteristics make SmCoThese characteristics make SmCo magnets ideal for applications requiring amagnets ideal for applications requiring a resistance to wide-ranging temperaturesresistance to wide-ranging temperatures and environments.and environments. Samarium cobalt www.indiandentalacademy.com
  22. 22. Alnico-alloysAlnico-alloys  The Aluminum/Nickel/CobaltThe Aluminum/Nickel/Cobalt combination is excellent for highcombination is excellent for high temperature use, and is readilytemperature use, and is readily available in rods or bars.available in rods or bars.  The direction of magnetizationThe direction of magnetization for Alnico is usually much longerfor Alnico is usually much longer than the other dimensionsthan the other dimensions (parallel to the length) for best(parallel to the length) for best results.results.  As cast material, it is gray toAs cast material, it is gray to dark brown in color, but looksdark brown in color, but looks metallic when ground.metallic when ground. www.indiandentalacademy.com
  23. 23.  Samarium iron nitride is a promising newSamarium iron nitride is a promising new material for permanent magnet applicationsmaterial for permanent magnet applications because of its high resistance tobecause of its high resistance to demagnetization, high magnetization and betterdemagnetization, high magnetization and better resistance than Nd-Fe-B to temperature andresistance than Nd-Fe-B to temperature and corrosion.corrosion. Samarium iron nitride www.indiandentalacademy.com
  24. 24. Design of Magnetic Attachments.Design of Magnetic Attachments. Magnet systems may be either anMagnet systems may be either an  Open fieldOpen field  Closed field designsClosed field designs  A cup typeA cup type  A sandwich typeA sandwich type  A modified split-pole typeA modified split-pole type  A split pole with slant magnetizationA split pole with slant magnetization  A cylinder typeA cylinder type www.indiandentalacademy.com
  25. 25.  An open field system consistsAn open field system consists of a cylindrical magnet withof a cylindrical magnet with open ends, it can be single oropen ends, it can be single or paired.paired.  For simple, cylindrical, openFor simple, cylindrical, open field magnet encased in nonfield magnet encased in non magnetic housing, magneticmagnetic housing, magnetic field is experienced outside thefield is experienced outside the magnetic specimen.magnetic specimen.  Only one pole is used forOnly one pole is used for attachment to the keeper.attachment to the keeper. www.indiandentalacademy.com
  26. 26.  In closed field system Consists ofIn closed field system Consists of paired magnets and an attachable andpaired magnets and an attachable and detachable keepers.detachable keepers.  The magnet pairs are arranged withThe magnet pairs are arranged with opposite poles adjacent and magnetopposite poles adjacent and magnet faces abut magnetizable alloy keepers.faces abut magnetizable alloy keepers.  In general, closed field magnets haveIn general, closed field magnets have higher contact forces than open fieldhigher contact forces than open field devices of an equivalent size.devices of an equivalent size. www.indiandentalacademy.com
  27. 27.  Attachment of closed-field magnets is moreAttachment of closed-field magnets is more efficient because both the north and south polesefficient because both the north and south poles can be used for attachment to the keeper andcan be used for attachment to the keeper and the keepers can contain the magnetic flux.the keepers can contain the magnetic flux.  The first closed field design was the split poleThe first closed field design was the split pole design, which consisted of 2 magnets arrangeddesign, which consisted of 2 magnets arranged with opposite poles adjacent to each other.with opposite poles adjacent to each other. www.indiandentalacademy.com
  28. 28.  A small magnetic field is attached to the top ofA small magnetic field is attached to the top of the magnets.the magnets.  Comparisons of the forces provided by pairedComparisons of the forces provided by paired magnets, single magnets and soft magneticmagnets, single magnets and soft magnetic material, and reversed and non-reversed polesmaterial, and reversed and non-reversed poles have been performed.have been performed.  Paired magnets provided a greater breakawayPaired magnets provided a greater breakaway force than a single magnet with a soft magneticforce than a single magnet with a soft magnetic keeper.keeper. www.indiandentalacademy.com
  29. 29.  A reversed split pole system was designed byA reversed split pole system was designed by Gillings, provided a greater force than a nonGillings, provided a greater force than a non reversed split pole design.reversed split pole design.  Various designs exist that are based on circularVarious designs exist that are based on circular and rectangular assemblies.and rectangular assemblies.  A magnet sandwich design, has been shown toA magnet sandwich design, has been shown to work well, the amount of retention depends onwork well, the amount of retention depends on the thickness of the side plates and base.the thickness of the side plates and base. www.indiandentalacademy.com
  30. 30.  Finite element analysis has been used to the design ofFinite element analysis has been used to the design of attachments to maximize that they provide.attachments to maximize that they provide.  A closed –field design consisting of a magnet in a cupA closed –field design consisting of a magnet in a cup which in turn is placed in an outer cup provides a higherwhich in turn is placed in an outer cup provides a higher retention force than a simple open field system.retention force than a simple open field system.  A circular closed field sandwich-type design provides aA circular closed field sandwich-type design provides a greater amount of retention, if keeper materials aregreater amount of retention, if keeper materials are made ellipsoidal, then retention will increase further.made ellipsoidal, then retention will increase further. www.indiandentalacademy.com
  31. 31. www.indiandentalacademy.com
  32. 32. www.indiandentalacademy.com
  33. 33. ADVANTAGESADVANTAGES  Ease of placementEase of placement  Automatic reseatingAutomatic reseating  Constant retention with many cyclesConstant retention with many cycles  Easy replacement if neededEasy replacement if needed  Small size with strong attractive forces.Small size with strong attractive forces.  Can be placed within the prosthesisCan be placed within the prosthesis  Dissipate lateral functional forcesDissipate lateral functional forces  Less need for parallel abutmentsLess need for parallel abutments  Can be used for implant – supported prosthesis.Can be used for implant – supported prosthesis.  Ease of cleaningEase of cleaning www.indiandentalacademy.com
  34. 34. DISADVANTAGESDISADVANTAGES  Low corrosion resistanceLow corrosion resistance  Cytotoxic effectsCytotoxic effects  High costHigh cost  Short track record.Short track record. www.indiandentalacademy.com
  35. 35. MAGNETIC RETENTIONMAGNETIC RETENTION  Application of magnetic force in retention ofApplication of magnetic force in retention of prostheses has been tried more than halfprostheses has been tried more than half century.century.  With the development of magnetic materialsWith the development of magnetic materials and manufacturing technique, it has become aand manufacturing technique, it has become a realization to use magnetic force to retain oralrealization to use magnetic force to retain oral and maxillofacial prostheses in recent 20 years.and maxillofacial prostheses in recent 20 years.  As a mature retentive technique, magneticAs a mature retentive technique, magnetic attachment has been applied in variousattachment has been applied in various prostheses more and more popularly now.prostheses more and more popularly now. www.indiandentalacademy.com
  36. 36. MAGNETIC RETENTION IN DIFFERENTMAGNETIC RETENTION IN DIFFERENT MAXILLO FACIAL PROSTHESESMAXILLO FACIAL PROSTHESES  EXTRA ORAL PROSTHESES-EXTRA ORAL PROSTHESES-  Free standing magnetic retention for prosthesis withFree standing magnetic retention for prosthesis with osseointegraded implants.osseointegraded implants.  Magnetic retention in endosteal implants used forMagnetic retention in endosteal implants used for facial prostheses.facial prostheses.  Magnetic retention in midfacial prostheses withoutMagnetic retention in midfacial prostheses without implants.implants.  Magnetic retention in combined prostheses.Magnetic retention in combined prostheses. www.indiandentalacademy.com
  37. 37.  Intra oral prostheses-Intra oral prostheses-  ObturatorsObturators www.indiandentalacademy.com
  38. 38. FREESTANDING MAGNETIC RETENTION FORFREESTANDING MAGNETIC RETENTION FOR EXTRAORAL PROSTHESES WITHEXTRAORAL PROSTHESES WITH OSSEOINTEGRATED IMPLANTSOSSEOINTEGRATED IMPLANTS  The use of extra oral Osseo integrated implantsThe use of extra oral Osseo integrated implants for prosthetic rehabilitation of facial defects isfor prosthetic rehabilitation of facial defects is now widely accepted and practiced throughoutnow widely accepted and practiced throughout world.world.  Extra oral Osseo integrated implants are notExtra oral Osseo integrated implants are not without problems, most common is hygiene ofwithout problems, most common is hygiene of the implant abutment.the implant abutment. www.indiandentalacademy.com
  39. 39.  The most common method of retentionThe most common method of retention used in conjunction with implants is theused in conjunction with implants is the bar splint and clip assembly, itbar splint and clip assembly, it provides good retention but theprovides good retention but the presence of the bar may inhibitpresence of the bar may inhibit abutment hygiene by preventingabutment hygiene by preventing sufficient patient access to the area.sufficient patient access to the area.  Other complication include the initialOther complication include the initial difficulty in placing the prosthesis anddifficulty in placing the prosthesis and fracture of the base if the clips are setfracture of the base if the clips are set too tightly.too tightly. www.indiandentalacademy.com
  40. 40.  The use of magnets inThe use of magnets in conjunction with a bar splint orconjunction with a bar splint or as a complete magneticas a complete magnetic superstructure have been wellsuperstructure have been well documented, however thedocumented, however the problem of abutment hygieneproblem of abutment hygiene may still be compromised bymay still be compromised by presence of superstructure orpresence of superstructure or bar.bar.  Newer generation magnets andNewer generation magnets and associated abutment magna-cupassociated abutment magna-cup components have beencomponents have been successfully used is a variety ofsuccessfully used is a variety of patients over the past 5 years.patients over the past 5 years. www.indiandentalacademy.com
  41. 41.  It is important to be selective in the use of freestandingIt is important to be selective in the use of freestanding magnetic retention.magnetic retention.  A common use of freestanding magnets has been in smallA common use of freestanding magnets has been in small orbital defects that are subject to minimal soft tissueorbital defects that are subject to minimal soft tissue movement.movement.  The original Neo-mini magnet has a pull force ofThe original Neo-mini magnet has a pull force of approximately 500 gm and when used for orbitalapproximately 500 gm and when used for orbital prostheses, where there is no fear of lateral displacement,prostheses, where there is no fear of lateral displacement, complete security of retention is assured.complete security of retention is assured. www.indiandentalacademy.com
  42. 42. www.indiandentalacademy.com
  43. 43. RETENTION OF MAGNETS IN ENDOSTEALRETENTION OF MAGNETS IN ENDOSTEAL IMPLANTS USED FOR FACIAL PROSTHESESIMPLANTS USED FOR FACIAL PROSTHESES  Facial defects, whether the result of trauma orFacial defects, whether the result of trauma or ablative surgery, are usually surgically treatedablative surgery, are usually surgically treated whereby lost parts are replaced by soft tissue orwhereby lost parts are replaced by soft tissue or bone grafts or both.bone grafts or both.  Some cases where reconstruction is notSome cases where reconstruction is not possible or contraindicated, the treatment ofpossible or contraindicated, the treatment of choice is facial prostheses to restore lostchoice is facial prostheses to restore lost structures.structures. www.indiandentalacademy.com
  44. 44.  At present, endosteal implants andAt present, endosteal implants and implant-supported epitheses are the stateimplant-supported epitheses are the state of art. Anchoring components may exist ofof art. Anchoring components may exist of bar constructions or magnets.bar constructions or magnets.  Magnets are often used as abutments forMagnets are often used as abutments for nasal, auricular and orbital epitheses.nasal, auricular and orbital epitheses. www.indiandentalacademy.com
  45. 45. www.indiandentalacademy.com
  46. 46.   End osseous Fixtures in the Calotte used for retaining Wigs With magnetic attachments  www.indiandentalacademy.com
  47. 47. Magnetic retention in midfacialMagnetic retention in midfacial prostheses without implants.prostheses without implants. www.indiandentalacademy.com
  48. 48. www.indiandentalacademy.com
  49. 49. MAGNETIC RETENTION IN AURICULAR PROSTHESES www.indiandentalacademy.com
  50. 50. MAGNETIC RETENTION INMAGNETIC RETENTION IN COMBINED PROSTHESESCOMBINED PROSTHESES www.indiandentalacademy.com
  51. 51. www.indiandentalacademy.com
  52. 52.  Intra-oral magnetic retentionIntra-oral magnetic retention The hollow facial epithese was made with medical silicone material and two pairs of magnetic attachments were also applied to connect the epithese and the obturator. www.indiandentalacademy.com
  53. 53. CONCLUSIONCONCLUSION  Magnets have been effectively used for theMagnets have been effectively used for the retention, maintenance and stabilization ofretention, maintenance and stabilization of maxillo facial prosthesis and they are effectivemaxillo facial prosthesis and they are effective for this purpose. Retention is like a castle heldfor this purpose. Retention is like a castle held together by proper Support and Stability. If anytogether by proper Support and Stability. If any one fails the whole castle comes crumblingone fails the whole castle comes crumbling down….down…. www.indiandentalacademy.com
  54. 54. Thank you For more details please visit www.indiandentalacademy.com www.indiandentalacademy.com

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