temporary anchorage devices

1. Temporary Anchorage
Devices
Dr.Lekshmi G Vijayan
First year PG

2. Contents:
 Introduction
 Definition
 Comparison of conventional and implant anchorage
 Classification of implants
 Indications
 Surgical procedure
 Instruction to patients

3.  Different implant systems
• Straumann orthosystem
• The Aarhus Anchorage System
• IMTEC mini ortho implants
• Spider screw anchorage system
• Skeletal anchorage system
• Bioresorbable implant system
 Biomechanical consideration
 Long term stability
 Failure of implants
 Conclusion
 References

4. Introduction
Anchorage is one of the important aspects of
orthodontic treatment

5.  TAD have gained profound applications in contemporary
orthodontic protocol
 To treat almost every genre of malocclusion be it arising from
dentoalveolar component , skeletal component or
combination of both
Jason B Cope.temporary anchorage device:A paradigm
shift.semin orthod11:3-9.2005

6. Temporary anchorage devices
Device that is temporarily fixed to bone for the purpose of
enhancing orthodontic anchorage either by supporting the
teeth of the reactive unit or by obviating the need for the
reactive unit altogether, and which is subsequently
removed after use.
Daskaloglannakis J:Glossary of orthodontic terms

7. HISTORY
 Gainsforth and Higley(1945)- subperiosteal vitallium implant
to retract maxillary canine in dogs
 Linkow (1969)-endosseous blade implants with perforations
for orthodontic anchorage.Had the potential for long term
masticatory function

8.  Kawahara (1975)-bioglass coated ceramic implant for
orthodontic anchorage
 Branemark (1964,1969,1977)-mentor of modern implant
surgery.
High compatibility and strong anchorage of titanium in
human tissue

9.  Creekmore(1983)-possibility of skeletal anchorage in orthodontics
Vitallium screw just below the anterior nasal spine
6mm intrusion achieved
Elastic thread from head of screw to arch wire.

10.  Roberts (1984)-used conventional two stage implant in the
retromolar region to help reinforce anchorage successfully
closing first molar extraction site in the
mandible.osseointegrated.
 Turley et al(1988)-endo-osseous implants in dogs as
anchorage for orthodontic and orthopaedic force

11.  Weherbein and collaegues (1990’s) –palatal implant called “straumann
orthosystem”
 Kanomi (1997)- first reported the clinical use of mini-implants for
orthodontic anchorage.
Implanted mini bone screw of 1.2mm diameter and 6mm length in the
alveolar bone between root apices of mandibular incisors
Elastic chain was tied to mandibular central incisor bracket and the implant
Intrusion of mandibular incisors..

12.  Fruedenthaler etal- first reported on immediately loaded , mechanically
retained orthodontic TADS
 Kim etal(2005) –use of drill free screws

13. Osseointegrated and mechanically retained
device
Classified by Dr.J.B.Cope

14. Osseointegration and dental implants
 Branemark et al introduced dental implants for tooth replacement
and prosthetic rehabilitation, osseointegration has remained the
singular goal.
 So in partially edentulous area these implants have been used
successfully in combined management of orthodontic and restorative
patients.

15. Problems
 Inability to place these implants in interdental areas,
owing to their bulkiness.
 Placement involved a two stage procedure and
therefore a long waiting time before loading.
 Anatomic limitations such as erupting teeth, possible
nerve damage or altered sensation
 The high cost
 Limitations in direction of force application

16. Development of microimplants
Initially screw were used 1.2 mm in
diameter and 5-10 mm in length
Drawback –
• lack of superstructure on the head
to attach elastics
• Ligature wire was tied on neck and
bend into hook
• Hook caused persistent
inflammation
Current therapy in orthodontics .Ravindra Nanda.Sunil Kapila.pg.no.291

17. Structure of an Implant
Head
Body
Abutment in prosthetic rehabilitation
Attachment source for Elastics & Coil
Springs in orthodontic treatment
Neck-trasmucosal portion that passes
through the mucosa
Screw- it is embed into cortical and medullary
bone to provide retention

18. Classifications

19. Biotolerant Stainless steel
Cobalt chromium alloy
Bioinert Titanium
Carbon
Bioactive Hydroxyapatite
Ceramic oxidized
aluminium
Resorbable Polylactic acid
Polyglycolic acid
Classification of
materials
Application of orthodontic miniimplants Jong Suk Lee Jung kook kim Robert vanarasdall

20. Titanium is a reactive metal - forms an oxide
layer, which protects it from chemical attack
Titanium is inert in tissue – i.e., no ions are
released which are reactive with the body tissues.
• Three times stronger than stainless steel
•Little response to electricity, heat and magnetic
properties
•Biocompatible
•Inert
 Type V TITANIUM has smallest amount of
alloy(6%aluminium,4%vanadium) of all grades
Application of orthodontic miniimplants Jong Suk Lee
Jung kook kim Robert vanarasdall pg no 1

21. Depending upon the area of implantation
Subperiosteal
Eg:onplants
Endosteal
Transosseous

22. TAD
BIOLOGICAL
TADS
BIOCOMPATIBLE
TADS
osseointegration mechanical
osseointegration mechanical
Ankylosed
teeth
Dilacerated
teeth
Dental
implants
Fixation
screw
Mini screw
MOST CURRENT ORTHODONTIC MINISCREWS ARE MECHANICALLY
RETAINED NOT OSSEOINTEGRATED
Jason b cope.TAD:a paradigm
shift .semin orthod 11;3-9

23. Biological response to osseointegrated and
mechanically retained TADS
POST IMPLANT
PERIOD
OSSEOINTEGRATED MECHANICALLY
RETAINED
IMMEDIATE BIOFILM,FORMATION
OF BLOOD CLOT
1 DAYS RED BLOOD CELL AND
INFLAMMATORY CELLS
ATTACHMENT OF
OSTEOBLASTS TO
TITANIUM SURFACE
3-5 DAYS APPEARANCE OF
OSTEOBLAST
DECREASE IN
INFLAMMATORY CELLS
1-4 WEEKS BONE REMODELLING BONE REMODELLING

24.  Primary stability of mechanically retained device depends mainly
on geometric design of implant ,bone quality,insertion technique
and tip moment
 Where as in osseointegrated it mainly depends on no loading
healing period.

25. Depending on shape
Screw type Disc type Blade type

26. Screw type
Disc type
Plate
type
Orthosystem
Aarhus implant
Micro implant
Spider screw
Onplant
Graz implant supported system
Zygoma anchorage system
Mini plates

27. Open implant
Closed implant
Application of orthodontic miniimplants
Jong Suk Lee Jung kook kim Robert vanarasdall
Based on head exposure

28. According to surface structure
Threaded Non Threaded
Greater surface area
Increase stability
Porous Non Porous
The vents in the implant body aids in the ingrowth of bone
Better interlocking between the implant & the bone

29. According to mode of insertion
• Self- tapping screw
• Self-drilling screws
Self tapping and self drilling scews

30. Self tapping
 Non cutting tip
 Require pilot hole of same length as implant
 More invasive
 Once pilot hole is drilled ,can be placed
without difficulty and minimal tissue damage
Self drilling
 Cutting tip
 Pilot hole not required
 High pressure required to drill through
cortical bone
 Compression of bone, patient
discomfort,resorption .
 Loss of tactile sensitivity.
The ideal combination appears to be a self drilling mini-implant system with
perforation of only the cortical bone but without a true pilot hole extending into
the bone the entire length

31. Comparison of loading
behaviour of selfdrilled and
predrilled miniscrews

32. Three dimensional stable anchorage is
needed.
Maximum anchorage case
Several missing teeth making it
difficult to engage posterior units
Intrude/extrude teeth
Close edentulous spaces
INDICATIONS
Indirect anchorage configuration for
anterior teeth retraction
Post treatment

33. To treat borderline cases with non
extraction method
Patient is not willing to undergo
orthognathic surgery.
Reposition of malposed tooth
Eruption of impacted tooth
Treat partial edentulism
Retraction of anterior teeth(class II divI)
Direct anchorage configuration for
protraction of mandibular right first
molar
Post treatment

34. Uprighting of molars
Mesiodistal tooth movement
Open bite correction
Molar mesialization
Distalization of molars
Orthopedic use-onplants can be
used for expansion and maxilla
protraction.
Correct undesirable occlusion
Hyper-extruded maxillary first molar before
temporary anchorage device intrusion.
Maxillary first molar following temporary
anchorage device intrusion.

35. Success and failures
Immediate failure
 Loosening occur during
initial healing phase
 Improper insertion site
 Improper handling
 Rare cortical bone
 Recent extraction socket
 Delayed failure
 Occur during active
orthodontic treatment
 Excessive loading
 Sudden impact during
mastication
 Contact with root

36. Inflammation
 Microimplants in oral mucosa,deep in vestibule or near the
frenum can cause persistant inflammation
 Periimplantitis is considered one of major complications that
can cause implant failure.

37. Root damage
 Root damage by drill or micro implant is not common.
 Evaluate the distance between roots from periapical
radiographs.
 If insufficient space, alignment of teeth should be taken to
widen interdentally space before placement.
 The resistance of cortical bone is quite strong, but after
penetrating, the resistance is minimal.
 If any strong resistance is felt, it may be root surface.

38. Procedure for implant placement

39. Standardised procedures
1. Preoperative examination
stage
2. Marking stage
3. Perforating stage
4. Guiding stage
5. Finishing stage

40. Patient selection
 Local condition
 Artificial valves/organs considered as high risk for infections.
 Metabolic bone disease/endocrine problems(diabetes).
 Uncontrolled cvs problems.
 Psychological problems
 Anatomic structures that interfere with implant placement
 Sites without space for implantation(because of root
proximity.
 Excessively developed Torus
 Sites with mech irritation:vestibule
 Sites with strong occlusal forces.

41. Pre operative information to the patient
 It takes 10 mins to place an implant.
 During implant placement, a feeling of stiffness may occur inspite of local
anesthesia.
 The teeth may be sore even though they are not touched during procedure.

42.  Soft tissue procedure like Frenectomy may be indicated in
certain patients.
 Position of implant may be modified during process
depending on soft tissue and hard tissue condition.

43. Radiographic evaluation
 Radiographic information is a prerequisite for ideal placement
site selection.
• 2 D panoramic radiograph
• 3 D CT
• IOPA
 Gives more detailed information about the implant sites, bone
depth, bone density and distance between adjacent roots.
 This data can be used for fabrication of surgical stent.
 During surgery ,a surgical guide is a safe and reliable tool that
allows precise insertion at designated site.

44. Implant site selection
 Indication and required mechanics.
 Attached gingiva placement, clear of frenulum.
 Sufficient interradicular distance.
 Avoid other anatomical structures.
 Adequate cortical bone thickness

45. Maxillary Microimplants sites
 Infrazygomatic crest area
 Maxillary tuberosity area
 Between the first and second molar buccally
 Between the first molar and second premolar buccally
 Between the lateral incisors and canine labially
 Between the maxillary incisors facially
 Between maxillary second premolar and first molar and
between first and second molar palatally
 Midpalatal area
Application of orthodontic miniimplants Jong Suk Lee Jung
kook kim Robert vanarasdall

46. Infrazygomatic crest area
Purpose
 For retracting the entire maxillary dentition
 For intrusion of anterior teeth
Bone quality is good with hard cortical tissue
Recommended microimplant-1.3&1.4mm diameter and length of
5 to 6mm
Chances of penetrating maxillary sinus

47. Influence of orthodontic mini
implant penetration of the
maxillary sinus in the
infrazygomatic crest region.

48. Maxillary tuberosity area
 Purpose -Retraction of maxillary posterior teeth
 Used when third molars are missing or having been extracted and healing
is complete
 Quality of bone is sometimes compromised,hence long implants required
 Incision not needed because of covering of attached gingiva.
 Used only in special situations
 Recommended size- diameter of 1.3-1.5mm and length of 7-8mm

49. Between the first and second molar
buccally
 Purpose- second choice to retract the maxillary anterior teeth
.
 Excellent location for applying intrusive force to maxillary
molars
 Surgical considerations-the root of second molar is tipped
mesially so sometimes no enough space between 1st and 2nd
molar roots
 Recommended size-1.2-1.3mm diameter
7-8mm length

50. Between maxillary first molar and second
premolar buccally
 Best area for retraction of maxillary anterior teeth and for
intrusion of molars
 If placed at a higher position,path of drill should be angles
approximately perpendicular to root of teeth.helps in avoiding
sinus injury

51. Between lateral incisors and canine
 Bilaterally used for intrusion of anteriors
 Used when cant of occlusion need to be changed

52. Between maxillary incisors facially
 Purpose-site is used for intrusive forces and torque control of the
maxillary incisors
 Surgical considerations-area has very good quality cortical bone and
attached gingiva.
 Microimplant usually must be placed in a slightly higher position to
produce intrusion of incisors
 Young patients ,there is gap in the midline suture area allowing the use of
a slightly large diameter micro implants


53. Between maxillary second premolar and first
molar and between first and second molar
palatally
 Can be used for anchorage in lingual orthodontics and for
intrusion of the maxillary molars in treating an anterior open
bite
 Should be long enough to penetrate through thick soft tissue
 The position of greater palatine artery and nerve must be
reviewed to avoid injuring them
 Palatal micro implants are the best choice for intrusion of
maxillary molar teeth

54. Midpalatal area
Used for any kind of tooth movement of the
maxillary posterior teeth,including unilateral
constriction of the arch
Can also be attached to transpalatal arch for
improving anchorage and distalizing molars
Good quality cortical bone

55. Mandible
1. Retromolar area
2. Between mandibular first and second molar buccally
3. Between mandibular first molar and second premolar
buccally
4. Between mandibular canine and premolar buccally
5. Mandibular symphysis facially
6. Edentulous area
7. Other areas

56. Retromolar area
 Uprighting of tilted mandibular molars and retraction of
mandibular teeth or whole dentition
 Retromolar area offer adequate thickness and high quality
cortical bone

57. Between first and second molar buccally
 used for retracting the mandibular anterior teeth as well as for
intrusion and distal movement of the mandibular molars
 Provide micro implant sites for the correction of scissor bite ie
buccal cross bite and Brodie bite
 Quality of cotical bone is excellent in this region
 Probability of root damage is less than with maxillary arch

58. Between first molar and second premolar buccally
 Used for retracting the mandibular anterior teeth as well as
for intrusion of mandibular posteriors
 Most common site to retract mandibular anterior teeth

59. Between canine and premolar buccally
 Used for protraction of mandibular molar
 Volume of buccal alveolar bone in this area is not as thick in
the posterior teeth

60. Mandibular symphysis facially
 Used for intrusion of mandibular incisors
 The distance between the roots of mandibular anterior teeth is
small,it is better to place micro implant diagonally

61. Edentulous area
 Best place for controlling teeth adjacent to an edentulous
space to achieve such movements as molar uprighting
 Excellent location because the cortical bone is of good quality
and there is no risk of root injury

62. Other areas
 Can be used in any areas of the mouth if there is bone
 Eg:- mandibular tori and bone adjacent residual root that will
be extracted at a later date can be used for placement of micro
implants

63. Bone density and MISCH classification
D 1
Dense cortical bone.
Anterior mandible
Buccal shelf area
midpalatal region
D 2
Porous cortical bone with coarse
trabeculae
Anterior maxilla
Midpalatal region
Posterior mandible
D 3 Porous cortical bone with fine
trabeculae
posterior maxilla
Posterior mandible
D 4
Fine trabeculae bone
Tuberosity region
Regions frm D
1 to D3 are
adequate for
TAD insertion.
TADS can be
placed in D1 to
D3 regions
with 70-
90percent
success.

64. Miniscrew shape: tapering
Reduced diameter at apical region can minimize possible
root injury
Large collar increases the surface area and helps in distribution of
stress on cortical bone.
Temporary Anchorage Device-Ravindra Nanda pg no:106

65. Composition of miniscrew

66. Growing patients considerations
 The success rates in individuals younger than 15 yrs of age is relatively low.
 To prevent injury to successor tooth buds,areas in which permanent teeth have
not yet erupted should be avoided.
 Predrilling through cortical bone is recommended to minimize surgical trauma.
 Use of light continuous forces is preferable to the use of heavy intermittent
force. (150g)
 Parasagittal area may be considered.

67. Armamentarium for surgical insertion
Straight screw
driver handle
Contraangle
screw driver
handle
Short and long driver tips

68. Driver assembly for contra
angle insertion on palatal
side with long guide drill
Miniscrew supplied in
sterilized capsules

69. Direct installation of
screw for straight
screwdriver
Direct installation of
screw for contra angle
screwdriver

70. Placement protocol
Topical anesthesia is sufficient for painless placement of
miniimplant.
Layers through which implant penetrates
Gingiva-strongly innervated-topical anesthesia effective for
desensitizing the neural input.
Periosteum-highly innervated-topical anaesthesia can reduce
painful stimuli if sufficient time is allowed for diffusion
Cortical plate-not highly innervated-anaesthesia not required
Cancellous bone-not highly innervated-anaesthesia not
required
Important feedback for the clinician if he comes close to
sensitive structures such as alveolar socket of tooth,nerve
canal,maxillary sinus

71. Marking stage
 Insertion site should be cleaned with povidone iodine.
 Periodontal probe is used to mark the horizontal and vertical
reference lines on gingiva.
 Thickness is measured with probe.
 Placing microimplants through oral mucosa requires 3 mm
long stab incision.
 The incision can be avoided with placement in attached
gingiva.

72. Perforating stage
This stage is important because cortical bone is the
component most resistant to implant insertion.
2 ways to prerforate –
 Orlus surgical drill
 Use of an implant

73.  The direction of screwing on the implant depends upon the
thread direction.
 For a right-handed thread the direction of rotation should be
clockwise
 For a left-handed thread, it should be counterclockwise.
 All miniscrews are mostly right-handed screws.

74.  Upper jaw:Relative to long axis of teeth ,placed at
30-40˚
 Advantages:
 Increased surface area of cortical bone contact with
micro implant
 Less chance of root contact and damage.
 Longer micro implants can be placed which enhance
stability.
 Lower jaw:Relative to long axis of teeth ,placed at
20-60
Placement angle

75. Guiding stage
 Implant should be inserted to the planned depth, and the
implant head should be exposed to an adequate extent.
 Finishing solely with rotational force is crucial to maximize
contact with the cortical bone.

76. Finishing stage
 During this stage, the screw should be engaged with the bone
and inserted at a planned angle.
 Implant should be inserted through rotation of the screw with
minimal vertical force

77. Head exposure
 Ligature wire extension tied around neck to apply force
 Head can be exposed while placing in Attached Gingiva
 Elastics or nickel titanium coil springs can be attached directly
to head.
 Vestibular depth and retromolar area:May get embedded by
overgrowth of surrounding soft tissues

78. Initial stability of miniscrew
 Periotest
Values greater than +10=insufficient initial fixation
-3 =recommended value
Orthodontic loading can be deferred for 1-2 weeks when the initial value is
relatively high.
Placement torque value increases as periotest value decreases resulting in
good primary stability
Takashi,KenMiyasva,MisuzuKawaguchi.Insertion torque and periotest
values are important factors predicting outcome after orthodontic
miniscrew placement.Am J Orthod Dentofaciail Orthop2017:152:483-8

79.  The majority of primary miniscrew stability comes from Cortical
Bone, with lesser stability coming from medullary bone.
 Upon placement, a miniscrew should have at least 0.5 mm to
0.75 mm of available bone around its circumference.
 As most miniscrews are intended to be placed and loaded at the
same visit, the miniscrew must have Adequate cortical bone
purchase and exhibit no mobility.

80. Post operative instructions
 There may be some amount of Pain.
 Ulceration may occur because of mechanical irritation.
 Any kind of mechanical irritation can cause loosening of an
implant.
 Brushing of the implant is also necessary, brush as gently as
possible.
 Never touch implant with finger or with the tongue.
 When eating a meal, hard food may cause mechanical
irritation.

81. Chlorhexidine rinse
 Minimum twice daily during the first week after implant
placement and continued throughout the treatment if needed
to minimize soft tissue inflammation
 Chlorxidine is cationic,bacteriostatic, that works via
substantivity within the oral cavity.
 Slows down epithelization,which limits soft tissue overgrowth.
 After rinsing with chlorhixide,patient should wait 30 mins
before brushing with fluoridated toothpaste

82. Emergency situations
 In the event of emergency an immediate visit to dental office
is recommended.
 Marked mobility means failure.
 An implant can be extruded unexpectedly because of
loosening, but this does not cause severe problems. In
general reimplantation is required.
 Continuous pain may be clinical sign indicating latent
problem.
 Swelling over an implant or drainage of pus may be clinical
sign of infection.

83. Loading protocols
 Loading protocols for screws involve immediate loading or a
waiting period of 2 weeks to apply orthodontic forces.

84. Removal
 Deep anesthesia is generally unnecessary
 Topical anesthesia or infiltration anesthesia may be
administered.
 There is no serious difficulty in bleeding control.
 Removal is done by turning in opposite direction of placement.
 If covered by soft tissue the head of the microimplant will need
to be incised and reflected to expose the head of implant.
 Apply slight and gentle force until the interface between
microimplant and bone breaks.
 If removal torque reaches fracture torque ,the clinician should

85. Various implant systems
Straumann Orthosystem Palatal Implants
The Aarhus Anchorage System Miniscrew Implants
IMTEC Mini Ortho Implants Miniscrew Implants
The Spider Screw Anchorage System Miniscrew Implants
The Skeletal Anchorage System Mini Bone Plate

86. Straumann Orthosystem
(Palatal Implants)
 Palatal implants are titanium screws with
a machined or modified surface
(SLA=Sand blasted, Large grit, Acid
etched).
 The substantial increase of the implant
surface obtained with these surface
modifications compensates for the
reduced length of the palatal implants.

87. Flange fixture
Transmucosal
abudment
screw with external
hexagon (bottom)
for rotational stability.
Length:3mm
Diameter:3.75mm

88. Due to its minimized length, this
implant has been used in the palate
for maximum anchorage.

89.  A threaded abutment is
mounted on the top of the
flange with an external
hexagon attached to prevent
rotation.
 The customized orthodontic
device which is fabricated in
the laboratory is screwed on
top of the abutment.
 Its 2.5 mm transmucosal
collar has a highly polished
surface.

90. Aarhus anchorage system
 Mini screw with a bracket like head.
 The screw driver can engaged the entire outer circumference
of the mini screw.
 Decreased the risk of fracture on removal.
 Available in either 1.5 or 2 mm in diameters.

91. The length of both the threaded screw and
the trans mucosal collar varies to
accommodate the thickness of the bone and
mucosa in different locations in the oral
cavity respectively.

93. IMTEC Ortho implant
 The Ortho Implant is 1.8-mm in outer diameter .
 1.6-mm core diameter at the head and tapers.
 There is a 0.7-mm-diameter hole in the ball head
of the implant and a
 Second 0.7-mm hole in the square helix of the
implant oriented at 90˚to the first hole .
 The holes allow a variety
of attachment to the implant.
Miniscrew implants:IMTEC Mini Ortho

94. The implant is available in 6, 8, 10 mm in lengths.
Ortho implant kit
 Soft tissue punch to aid in placement of the implant
 Variety of different size drivers,
 1.1 mm pilot drill

95. Spider screw
 Self-tapping miniscrew
1.5 mm 2 mm
6mm 7mm
8mm 9mm
10mm 11mm
The screw head has an internal .021" × .025" slot,
 An external slot of the same dimensions
 .025" round vertical slot.

96.  It comes in three heights to fit soft tissues of
different thicknesses:
Low profile screw
 Longer Transmucosal Collar
 A Flat Head
 Utilized In the thick soft tissues of posterior
segments

97. Low Profile Flat Screw
 same head
 a short collar
 thin tissue of the patient’s anterior segments,
Regular design
 An intermediate length
 A raised head,
 And when combined with a resin core can be used as a
Temporary prosthetic abutment.

98. Skeletal anchorage system
 Comprised of bone plates and fixation screws.
 Made of commercially pure titanium that is biocompatible
and suitable for osseointegration.
 3 PARTS
 Head
 Arm
 body
Minibone plates:The Skeletal Anchorage System
Semin Orthod 2005 11:47-56

99. Head
 Exposed intraorally and is positioned outside of the dentition
so that it does not interfere with the tooth movement.
 The head component has 3 continuous hooks for
attachment of orthodontic forces.

100. Arm
Transmucosal and is available in
three different lengths
 short 10.5 mm
 medium 13.5 mm
 long 16.5 mm
Body
Positioned subperiosteally and is available
in three different configurations.
The T plate, the Y plate, and the I
plate.

102. Advantage
 Enables not only single molar distalization but enmass movement of max
and mand posteriors with only minor surgery.
 Do not interfere with tooth movement as they can be placed away from
tooth
 Useful where we need consistent and reliable delivery force for prolonged
periods
Limited use of miniplate
 The perception that they are difficult to place
 Unpleasant and difficult for the patient to tolerate
 Cumbersome for the orthodontist to use
 Might not provide significant advantages for treatment.

103. Biodegradable implant system
 BIOS implant comprises a
biodegradable implant body and a
variable metal abutment as a
superstructure.
 The metal abutment is anchored by
means of a metrically-standardized
internal thread located in the implant.

104. The technological innovation of this development is, the
biodegradable lactide copolymer.
The resorbable implant body is produced
by injection moulding and sterilized using ethylene
oxide.

105. Extra radicular bone screws
 Placed at infrazygomatic crest and
buccal shelf areas
 Stainless steel is preferred than Ti for
bonescrews since it provide greater
fracture resistance
 Two most specific indications
full arch distalization in classII and Class
III malocclusion
distalization of arch in retreatment case
of anchorage loss

106. Placement of Bone Screws
Maxilla

107. • No pre-drilling, raising of flap or vertical slit in the mucosa is required
• Immediate loading is possible and a force of up to 300–350 g can be
taken up by a single bone screw.

108. Mandible-
• For placement of bone screws in the BS area of mandible (2nd
molar region), initial point of insertion is inter-dentally between
the 1st and the 2nd molar and 2 mm below the mucogingival
junction. The self-drilling screw is directed at 90° to the occlusal
plane at this point.
• Later changes to 60-70

109. Advantage:
1.No risk of root contact
2.Hardly any complication assosciated with insertion process
of bone screw except for minor bleeding.
3.Less chances of occlusal plane rotation and development of
posterior open bite and anterior deep bite compared to mini
screws.
4.Stability and success rate of bone screw are far more
superior purely beacause of their larger dimension and
placement site having excellent quality of cortical bone22
Disadvantage:
Chances of gingival over growth on screws

110. Types of anchorage
 DIRECT ANCHORAGE
 INDIRECT ANCHORAGE

111. DIRECT ANCHORAGE
 Force is directly applied
from the implant to tooth or
group of teeth that are to
be moved.
 Pulling mechanics
 Simple installation and
hidden force vectors
INDIRECT ANCHORAGE
 Miniimplants are used to
stabilize a group of
teeth,creating implant-
dental anchorage unit.
 Implant placement is
independent of type of
tooth movement desired
 Traditional orthodontic
mechanism

112. Force characteristics delivered using mini screw
 Single linear force
 Moderate magnitude of force
 Intrusive component of force
 A single miniscrew is expected to withstand approx 200-300 gms of force
which appears to be sufficient to move segments of teeth.
 Multiple miniscrews may be indicated to provide anchorage to heavier
forces for movement of larger segment such as post segment of whole
arch.
 When elastic chain or nickel titanium coil springs are engaged to the
screw head,they generate a linear force whose line of action is
represented by direction of elastic component
 As miniscrews are placed apical to archwire,forces have an intrusive
component
Temporary Anchorage Device-Ravindra Nanda

113. Biomechanical consideration in
microimplant anchorage
 The type of tooth movement that can be produced with same
microimplant anchorage is determined by same
biomechanical principles and considerations that operate
during conventional orthodontic treatment
 Eg: force,moment, centre of resistance, center of rotation etc..

114. Anterior enmasse retraction mechanics in extraction
cases
3 categories of retraction mechanics
Low pull mechanics
Medium pull mechanics
High pull mechanics

115. Medium pull mechanics
• Maxillary microimplants are placed about 8-10mm above the
main arch wire
• If force is applied from a medium pull microimplant to hook
located between the lateral incisors and canine that extend 6 to
7mm vertically,the maxillary occlusal plane can be maintained
• Treating pts with normal over bite relationships

116. Low pull mechanics
• Microimplants placed less than 8mm from the main arch
• Maxillary occlusal plane can be rotated in the clockwise direction
• Useful in treating pts who have an openbite or openbite tendency

117. High pull mechanics
• More than 10mm away from the main arch
• Maxillary occlusal plane will rotate in the counter clockwise direction
• Use full in treating pts who have a deepbite or deebite tendency

118. Anterior intrusion mechanics
• Force originating from a single microimplant is placed between
the maxillary central incisor root is adequate to intrude anterior
dentition
• Transverse cant to occlusal plane-two microimplants can be
placed bilaterally between the central lateral incisor roots

120. Anterior enmasse retraction with anterior
intrusion
• Deepbite cases- high pull mechanics recommended
• But difficult to place microimplants higher in the buccal vestibule
• Two posterior microimplants in low or medium pull orientation
combined with one or two anterior implants
• Anterior intrusion microimplants will counteract the tendency for
incisors to tip lingually during the retraction

122. Molar intrusion mechanics for openbite
cases
• If 1 mm of absolute molar intrusion is achieved posteriorly,an
anterior open bite of 2-3mm will closed anteriorly
• Implants can be placed between the roots of maxillary 2nd
premolar and first molar and or first molar and second molar
buccally or palatally for intrusion of maxillary molars
• A transpalatal arch used for palatal support in the absence of
palatally place microimplants
• Mandibular arch- not advisable to insert microimplants
lingually,lingual holding arch can be used for support instead

125. Molar distalization mechanics for nonextraction
cases
Microimplants can be place between the roots of second premolar and first
molar ,NiTi coil spring can be used

127. Retraction of entire maxillary or
mandibular dentition
• Two buccally placed microimplants can provide sufficient
anchorage to move the the entire maxillary or mandibular
dentition
• Usually between the roots of second premolar and first molar
• If adequate volume of bone exist buccal to the root,entire dentition
can be retracted in one stage
• If microimplants touches the second premolar root during
retraction ,the first microimplant is removed and a new one is
placed just distal to first one
Kyu Rhim,HyeRan Choo,Peter Ngan.Timely relocation of
mini-implants for uninterrupted full arch
distalization:Am J Orthod Dentofacial Orthop
2010:138:839-49

129. How should mobile implants be managed after placement
 Choose another insertion site
 Can be inserted on same site after few days
 Or choose a higher diameter implant

130. Is CBCT is needed?
 Probably not in all the cases
 In private practice CBCT has some shortcomings that need to
be considered.
 For implant placement in some areas like Infrazygomatic
Crest where there is reduced bone depth and more chance of
maxillary sinus perforation,CBCT is invaluable diagnostic
tool.

131. Conclusion
 Placed in either alveolar or extra-alveolar bone for the purpose of
providing orthodontic anchorage, temporary anchorage devices (TADs)
are removed once they complete their function in the treatment regimen.
 While they do not necessarily increase the rate of orthodontic correction
 They helped converting many borderline surgical cases to non surgical
and extraction cases to non extraction and even bringing about esthetic
impact which was difficult to achieve by conventional mechanics.

132. References
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vanarasdall
 Su-Jung Mah,a Pil-Jun Won,b Jong-Hyun Nam,b Eun-Cheol Kim,c and
Yoon-Goo Kangd. Am J Orthod Dentofacial Orthop 2015;148:849-61
 Makato Nishimura,Minayo Sannohe.Am J Orthod Dentofacial Orthop
2014:145:85-94
 Jason B Cope.temporary anchorage device:A paradigm shift.semin
orthod11:3-9.2005
 Clin Oral Implants Res 2005:16;575-78
 Current therapy in orthodontics Ravindra Nanda, Sunil K

133.  Systematic review of the experimental use of temporary skeletal
anchorage devices in orthodontics.Am J Orthod Dentofacial Orthop
2007
 Minibone plate .The skeletal anchorage device system. Semin orthod
2005;11:47-56.
 The Spider Screw for Skeletal Anchorage: JCO 2003;February(37):90-
7.
 Miniscrew implants:IMTEC Mini Ortho Implants Semin Orthod
2005:11,32-39
 M. Leo1, L. Cerroni2, G. Pasquantonio3, S.G. Condò4, R. Condò2 .
 Temporary anchorage devices (TADs) in orthodontics: review of the
factors that influence the clinical success rate of the mini-implants Clin
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134.  . Nishimura M, Sannohe M, Nagasaka H, Igarashi K, Sugawara J.
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Effectiveness of orthodontic miniscrew implants in anchorage
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Orthopedics. 2017 Mar 1;151(3):440-55.
 Takashi,KenMiyasva,MisuzuKawaguchi.Insertion torque and periotest
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miniscrew placement.Am J Orthod Dentofaciail Orthop2017:152:483-8

135.  Kee Joon Lee,Sung Jin Kim.Advanced biomechanics for total arch
movement and non surgical treatment for hyperdivergent faces.Semin
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 Kyu Rhim,HyeRan Choo,Peter Ngan.Timely relocation of mini-
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