Anchorage in orthodontics

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Anchorage in orthodontics

  1. 1. FATHIMA SISINI FINAL YEAR PART ONE
  2. 2. DEFINITION • Anchorage in orthodontics as the nature and degree of resistance to displacement offered by an anatomic unit for the purpose of tooth movement. (GRABER) • Anchorage is the site of delivary from which force is exerted(White and Gardnier)
  3. 3. CLASSIFICATION(MOYERS) • ACCORDING TO MANNER OF FORCE APPLICATION SIMPLE STATIONARY RECIPROCAL • ACCORDING TO JAWS INVOLVED INTER MAXILLARY INTRA MAXILLARY • ACCORDING TO SITE INTRA 0RAL EXRAORAL MUSCULAR
  4. 4. • INTRA ORAL;-TEETH,ALVEOLAR BONE,BASAL BONE • EXTRA ORAL;- CERVICAL,OCCIPITAL,CRANIAL,FACIAL • MUSCULAR • According to number of anchorage units;-single or primary,compound,multiple or reinforced CLASSIFICATION cntd….
  5. 5. INTRA ORAL ANCHORAGES • 1) teeth • 2)alveolar bone • 3)basal bone • 4)musculature
  6. 6. TEETH • WHEN ONE TEETH MOVES THE OTHERS CAN ACT AS ANCHORAGE UNITS,IT DEPENDS ON -ROOT FORM -ROOT SIZE -NO OF ROOTS -ROOT LENGTH -ROOT INCLINATION
  7. 7. ROOT FORM • FLAT-RESIST MOVEMENTS IN MESIO-DISTAL DIRECTION,BUT LITTLE RESISTANCE BUCCOLINGUALLY EG;-MANDIBULAR INCISORS AND MOLARS,BUCCAL ROOT OF MAXILLARY MOLARS • ROUND:-RESIST HORIZONTALLY DIRECTED FORCE IN ANY DIRECTION EG;-BICUSPID,PALATAL ROOT OF UPPER MOLARS • TRIANGULAR;-MAXIMUM ANCHORAGE EG;-CUSPIDS,MAXILLARY CENTRALS AND LATERALS
  8. 8. SIZE AND NUMBER OF ROOTS • MULTIROOTED TEETH HAVING THE MAXIMUM SIZE HAVE MAX. ANCHORAGE ROOT LENGTH;-DIRECTLY PROPOTIONAL TO ANCHORAGE AXIAL INCLINATION;-ANCHORAGE IS MORE WHEN FORCE EXERTED IS OPPOSITE TO THAT OF AXIS OF INCLINATION OF TEETH ANKYLOSED TEETH;-NO PDL, SO NO MOVEMENT-EXCELLENT ANCHORAGE
  9. 9. ALVEOLAR BONE • ALVEOLAR BONE RESIST TOOTH MOVEMENT UP TO ITS LIMIT,BEYOND THAT IT ALLOW TOOTH MOVEMENT BY REMODELLING • HEALTHY ALVEOLAR BONE-MORE ANCHORAGE
  10. 10. BASAL BONE • CERTAIN AREAS ACT AS RESISTANCE AREAS-PROVIDE GOOD ANCHORAGE- HARD PALATE,LINGUAL SURFACE OF MANDIBLE
  11. 11. MUSCULATURE • HYPERTONIC LABIAL MUSCULATURE USED FOR ANCHORAGE IN LIP BUMPER
  12. 12. EXTRA ORAL • 1)CRANIUM(OCCIPITAL OR PARIETAL ANCHORAGE:-ANCHORAGE OBTAINED FROM OCCPITAL OR PARIETAL BONE EG:-HEAD GEAR TO RESTRICT MAXILLARY GROWTH • 2)CERVICAL:-ANCHORAGE FROM CERVICAL OR NECK REGION • EG:-CERVICAL HEAD GEAR • 3)FACIAL BONES:-FACE MASK USED TO PROTRACT MAXILLA TAKE ANCHORAGE FROM MANDIBULAR SYMPHYSIS REVERSE HEAD GEARS TAKE ANCHORAGE FROM FOR HEAD AND CHIN
  13. 13. SIMPLE ANCHORAGE • IS THE DENTAL ANCHORAGE SUCH THAT MANNER AND APPLICATION OF FORCE IS SUCH THAT IT TENDS TO CHANGE THE AXIAL INCLINATION OF THE TEETH • THE RESISTANCE OF ANCHORAGE UNITS TO TIPPING IS USED TO MOVE OTHER TEETH • THE COMBINED ROOT SURFACE AREA OF THE ANCHORAGE UNIT MUST BE DOUBLE TO THAT OF TEETH TO BE MOVED • EG:-PALATALY PLACED PREMOLAR IS PUSHED IN TO THE ARCH BY REST OF THE TEETH AS ANCHOR UNITS
  14. 14. STATIONARY ANCHORAGE • MANNER AND APPLICATION OF FORCE TEND TO DISPLACE THE ANCHORAGE UNIT • RESISTANCE PROVIDED BY THE ANCHORAGE UNITS IS AGAINST BODILY MOVEMENTS(DISPLACEME NT)
  15. 15. RECIPROCAL ANCHORAGE • RESISTANCE OFFERED BY TWO MALPOSED UNITS WHEN THE APPLICATION OF TWO EQUAL AND OPPOSITE FORCES TEND TO MOVE EACH UNIT TO A MORE NORMAL POSITION • EG:-CLOSURE OF MIDLINE DIASTEMA CROSS BITE ELASTICS,EXPANSION APPLIANCES
  16. 16. INTRA MAXILLARY ANCHORAGE • TEETH ARE TO BE MOVED AND THE ANCHORAGE UNITS ARE IN THE SAME ARCH
  17. 17. INTER MAXILLARY ANCHORAGE • TEETH ARE TO BE MOVED IN ONE ARCH AND RESISTRANCE UNITS ARE IN OPPOSITE ARCH • EG:-CLASS II ,CLASS III ELASTICS
  18. 18. SINGLE OR PRIMARY ANCHORAGE • SINGLE TEETH WITH MORE ALVEOLAR SUPPORT USED TO MOVE ONE WITH LESSER SUPPORT
  19. 19. COMPOUND ANCHORAGE • ANCHORAGE PROVIDED BY MORE THAN ONE TEETH WITH GREAT SUPPORT TO MOVE TOOTH WITH LESS SUPPORT
  20. 20. REINFORCED ANCHORAGE • MORE THAN ONE TYPE OF RESISTANCE UNIT IS UTILIZED • EG:-A)TO AUGMENT THE INTRA ORAL ANCHORAGE, EXTRA ORAL ANCHORAGES TRANS PALATAL ARCH,AND LINGUAL ARCHES IS USED B)UPPER ANTERIOR INCLINED PLANE USED FOR FORWARD MOVEMENT OF MANDIBLE USES MUSCULAR ANCHORAGES
  21. 21. MINI DENTAL IMPLANTS • USED IN PATIENTS HAVING MULTIPLE LOST TEETH OR HYPODONTIA OR TO AUGMENT TEETH WITH PERIODONTAL DISEASES • CLASSIFICATION -ACCORDING TO EXPOSURE OF HEAD:- OPEN-HEAD IS EXPOSED TO ORAL CAVITY-USED WHEN SOFT TISSUES ARE NOT MOVABLE CLOSED-EMBEDED UNDER SOFT TISSUES-MOVABLE TISSUES
  22. 22. • ACCORDING TO IMPLANT PLACEMENT 1)SELF TAPPING METHOD:-IMPLANT TAPPED IN TO A PREVIOUSLY DRILLED HOLE- SMALLER DIAMETER IMPLANTS 2)SELF DRILLING METHOD:-IMPLANT IS ITSELF DRILLED IN TO THE BONE-LARGER DIAMETER IMPLANT • ACCORDING TO THE PATH OF INSERTION:- 1)OBLIQUE;-30=60DEGREES TO LONG AXIS OF TEETH-WHERE INTER RADICULAR BONE IS NARROW 2)PERPENDICULAR;-INSERTED PERPENDICULAR TO THE BONE SURFACE- WHEN SUFFICIENT INTER RADICULAR BONE PRESENT
  23. 23. SITE OF PLACEMENT OF MICRO IMPLANTS • 1)MAXILLARY TUBEROCITY • 2)INFRA ZYGOMATIC CREST • 3)BUCALLY B/W MAX 6 & 7 • 4)BUCALLY B/W MAX 5&6 • 1)MAXILLRY POSTERIORS • 2)RETRACTION OF MAX.ANTERIORS &INTRUSION OF MAX.POSTERIORS • 3)SAME AS ABOVE • 4)SAME AS ABOVE &TO TIP BUCALLY
  24. 24. • 5)BUCALLY B/W MAX 3&4 • 6)LABIALLY B/W MAX. CENTRALS • 7)PALATALLY B/W MAX 5&6 • 5)DISTAL &MESIAL MVMT OF MAX.MOLARS AND INTRUSION OF MAX BUCCAL TEETH • 6)INTRUSION AND TORQUE CONTROL OF INCISORS • 7)RETRACTION OF MAX ANTERIORS AND INTRUSION OF MAX MOLARS
  25. 25. • 1)RETROMOLAR PADS • 2)BUCALLY B/W MAND. 6&7 • 3)BUCALLY B/W 4&5 • 4)BUCALLY B/W 3&4 • 5)MADIBULAR SYMPHYSIS • 1)UPRIGHTING&RETRA CTION OF MAND.TEETH • 2)INTRUSION &DISTAL MVMT OF MAND MOLARS,RETRACTION OF MAND.ANTERIORS • 3)SAME AS ABOVE • 4)PROTRACTION OF MOLARS • 5)INTRUSION OF MANDIBULAR ANTERIORS SITES IN MANDIBLE
  26. 26. ANCHORAGE PLANNING • FACTORS AFFECTING ARE:- 1)NO; OF TEETH BEING MOVED:-TO MOVE GREATER NO;OF TEETH, ANCHORAGE SHOULD BE MORE 2)TYPE OF TEETH:-TEETH HAVING MORE SURFACE AREA REQUIRE MORE ANCHORAGE 3)TYPE OF MOVEMENT:-BODILY MOVEMENT REQUIRE MORE ANCHORAGE 4)DURATION:-PROLONGED TREATMENTS REQUIRE GOOD ANCHORAGE 5)SKELETAL GROWTH PATTERN:- A)VERTICAL-REQUIRE MORE ANCHORAGE DUE TO POOR TONICITY OF FACIAL MUSCLES B)HORIZONTAL-VICE VERSA
  27. 27. • 6)OCCLUSAL INTERLOCK:-GOOD OCCLUSION=GOOD ANCHORAGE • ANCHORAGE LOSS:-UNWANTED TOOTH MOVEMENTS DURING ORTHODONTIC THERAPY • BASED ON THE ANCHORAGE LOSS THE ANCHORAGE DEMAND OF THE EXTRACTION CASES ARE OF THREE TYPES • MAXIMUM,MODERATE,MINIMUM
  28. 28. MAXIMUM ANCHORAGE CASES • ANCHORAGE DEMAND IS VERY HIGH • NOT MORE THAN 1/4TH OF THE EXTRACTION PLACE SHOULD BE LOST BY ANCHORAGE LOSS • SO AUGMENTATION OF ANCHOR TEETH REQUIRED
  29. 29. MODERATE ANCHORAGE CASES • ANCHORAGE LOSS 1/2TH TO 1/4TH OF EXTRACTION SPACE
  30. 30. MINIMUM ANCHORAGE CASES • ANCHORAGE LOSS CAN BE MORE THAN 1/2TH OF EXTRACTION SPACE
  31. 31. BIBLIOGRAPHY • TEXT BOOK OF ORTHODONTICS-S I BHALAJI,PROFET • WWW.FUNNYTOOTH.COM • WWW.WIKIPEDIA.COM

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