Temporary anchorage devices in orthodontics

Mini implants
in
Orthodontics.
Dr Ravikanth Lakkakula

 Defination of implant.
 Introduction.
 Historical background.
 Parts of implants.
 Types of implants.
 Bone physiology.
 Indications and contraindications.
 Treatment planning.

 Treatment considerations.
 Sites of implants.
 Implant as a absolute anchorage.
 Comparision between conventional and implant anchorage.
 Surgical procedure.
 Comparision of different types of miniimplants.
 applications.
 Conclusion.

Definition of implant
 Implants are defined as alloplastic device (foreign
substance i.e.metal,ceramic,plastic) which are
surgically inserted into or onto the jaw bone -
Boucher
 Implantation is transfer of nonliving tissue into
biologic system.
 Osseointegration: An intimate structural contact at
the implant surface and adjacent vital bone,
devoid of any intervening fibrous tissue -
Branemark (1983).

Introduction
 Anchorage control is one of the most important
aspects of orthodontic treatment. The success of
orthodontic treatment hinges on the anchorage
protocol planned for a particular case. Use of
extraoral anchorage devices such as headgears
requires full patient cooperation, which is
sometimes not possible and is unpredictable.
 Introduction of implants in orthodontics have solved
this problem. Implants have become one of the
best sources of reliable anchorage. Mini implants
have revolutionized the field of anchorage in
orthodontics.

This new modality has been called by several names, some of
the popular ones are
 Mini implants,
 Microimplants,
 Skeletal anchorage,
 Temporary anchorage Device.

 Use of implants as a source of anchorage has number of
advantages as compared to traditional anchorage such as
1. no patient cooperation,
2. easy to use,
3. shortening of treatment time,
4. good control on tooth movements.
Branemark and co-workers" (1965) reported the successful
osseointegration of titanium implants in bone; many
orthodontists began investigating in using implants for the
purpose of orthodontic anchorage.

Historical background.
• The concept of metal components inserted into
maxilla and mandible to enhance the orthodontic
anchorage was first published in 1945 by
Gainsforth and Higley ,with use of vitallium screws to
effect tooth movement in dog ramus.
Despite some success ,the resultant tooth movent was
limited due to implant loosing within one month of
commencing toth movement.
 Two decades later, lincow(1969, 1970) used
endosseous mandibular blade-vent implants in a
patient to apply class II elastics , but did not report
on long term stability.

 Vitreous carbon implants showed failure rate of 67% , when
undergoing orthodontic loading and atempt at using bioglass
coated ceramic implants for orthodontic anchorage were
almost as disappointed.
 All the above materials are compatible with bone but none of
them showed consistent long term attachment of bone to
implant surface, which means they did not achieve true
osseointegration.

 In 1964, Branemark et al observed a firm anchorage of titanium to bone
with no adverse tissue response . In 1969, they demonstrated that titanium
implants were stable over 5 years and osseointegrated in bone under
lightmicroscopic view. Since then, dental implants have been used to
reconstruct human jaws or as abutments for dental prostheses.
 The first clinical report in the literature on the use of TADs appeared in
1983 when Creekmore and Eklund used a vitallium bone screw to treat a
patient with a deep impinging overbite by intruding upper incisors.

 In 1984, Roberts et al corroborated the use of implants in orthodontic
anchorage. 6 to 12 weeks after placing titanium screws in rabbit femurs, a
100-g force was loaded for 4 to 8 weeks by stretching a spring between the
screws. All but 1 of 20 implants remained rigid. Titanium implants
developed osseous contact, and continuously loaded implants remained
stable. The results indicated that titanium implants provided firm osseous
anchorage for orthodontics and dentofacial orthopedics.

Idea of absolute anchorage creekmore(1983)
Ankylosed tooth Kokich(1985)
Dental implants Roberts(1990,2002)
Shellhert(1996)
onplants Block(1995)
Orthoplants(palatal implants) Wehbein(19996)
Zygoma ligatures Melsen(1998)
miniscrews Costa(1998)
Paik(2002)
Miniscrews with miniplates Umimori(1999)
Chang(2002)
Clerck(2002)
Kanomi(1997)
Park(2001,2002)
Lee(2001)
Bae(2002)

Parts of implant
• Implant head – It serves as the abutment and in the case of an Orthodontic
implant, could be the source of attachment for elastics/ coil-springs.
• Implant body- It is the part embedded inside bone. This may be a screw type
or a plate type . Thescrew and plate design that has been used in Orthodontics
as the skeletal anchorage system varies from these conventional plate
implants.
 Implant Neck- It is the part of the implant which connects the Head and the
Body.
Implant head Threads in the Implant body

Types of the implants

Implants
Endosteal subperiosteal transosseous
Root form plate/blade form

Depending upon area of implantation
- endosteal
-subperiosteal
-transosseous

Endosseous implant
 These are partially submerged and anchored within
bone. These have been the most popular and the widely
used ones. Various designs and composition are available
for usage in specific conditions. The endosseous
implants are most commonly employed types for
orthodontic purposes.

Subperiosteal implant
 In this design, the implant body lies over the bony ridge. The
subperiosteal design currently in use for orthodontic purposes
is the “Onplant”.

Transosseous implants
 In this particular variety, the implant body penetrates the
mandible completely. These have enjoyed good success rate in
the past. However they are not widely used because of the
possible damage to the intrabony soft tissue structures like the
nerves and vessels .

 Depending upon their shape
- Screw type.
-Bladed type.
-Cylindrical.
• Based on the configuration design .
-Root form implants: These are the screw type
endosseous implants and the name has been derived
due to their cylindrical structure .
- Blade / Plate implants:

Plate / Blade form –
As the name suggests the basic shape of plate or blade implant is
similar to that of a metal plate or blade in cross section . Some
plate blade forms have combination of parallel & tapered sides.
Plate / Blade forms are unique among implants in that they can
function successfully in either osseointegration or
osteopreservation mode of tissue integration.

According to the surface structure.
Threaded or Non-threaded:
The root form implants are generally threaded as this provides for
a greater surface area and stability of the implant.
Porous or Non Porous:
The screw type implants are usually non porous,whereas the plate
or blade implants (non threaded) have vents in the implant body
to aid in in growth of bone and thus a better interlocking between
the metal structure and the surrounding bone.

Implant materials
 Material must be : nontoxic, biocompatible, possess excellent mechanical
properties, and provide resistance to stress, strain, and corrosion.
3 categories :
 Biotolerant (stainless steel, chromium cobalt alloys)
 Bioinert (titanium, carbon)
 Bioactive (hydroxyl apatite, ceramic oxidized aluminum)

Based on material of construction
 Gold alloys.
 Vitallium.
 Cobalt-chromium.
 Vitreous carbon.
 Aluminium oxide ceramics.
 Nickel –chromium vanadium.
 Titanium alloy.
 Titanium alloy with hydroxyappatite coating.

Alloplastic materials

 Based on condition of exposure of the implant.
- Open implants-contact with oral cavity
- Closed implants- used for skeletal fixation.

CLASSIFICATION OF IMPLANTS FOR ORTHODONTIC ANCHORAGE
1. According to the shape and size:
I) Conical (Cylindrical)
a) Miniscrew Implants
b) Palatal Implants
c) Prosthodontic Implants
II) Mini plate Implants
III) Disc Implants (Onplants)
2. According to Implant bone contact:
I) Osteointegrated
II) Non-osteointegrated
3. According to the application:
I ) Used only for orthodontic purposes. (Orthodontic Implants) or TAD(temporary
anchorage devices)
I I ) Used for prosthodontic and orthodontic purposes.

Based on the implant morphology:
a) Implant discs ------- Onplant
b) Screw designs :
i. Mini-Implant
ii. Orthosystem implant system
iii. Aarhus implant
iv. Micro-implant
v. Newer systems
- Spider screw,
- OMAS system,
- Leone miniimplant,
- Imtec screw etc.
c) Plate designs
i. Skeletal Anchorage system (SAS)
ii. Graz implant supported system
iii. Zygoma anchorage system

Bone physiology

IMPLANT-BONE INTERFACE
The relationship between endosseous implants and bone
consists of one of two mechanisms :
Osseointegration : when the bone is in intimate contact with the
implant, or fibroosseous integration, in which soft tissues, such
as fibers and/or cells, are interposed between the two surfaces.
The proponents of the fibro-osseous system of implant retention
opinon that the presence of a dense collagenous tissue between
implant and bone will act as an osteogenic membrane.

The osseointegration concept proposed by Branemark et al and
called functional ankylosis by Schroede .
it states that there is an absence of connective tissue or any
nonbone tissue in the interface between the implant and the
bone. A more accurate term, microinterlock, where tissue and
implant are juxtaposed , providing a bioinert fixation with
surface porositiy grooves, or beads.
Osseointegration refers to the direct contact of bone and
implant at the light microscope level . Osseointegration never
occurs on 100% of the implant surface. Successful cases will
have between 30% -95% of the implant.

Bone Tissue :
Three distinct types of bone (woven, lamellar, and
composite) are involved in postoperative healing and
maturation of the osseous tissue supporting an implant .
Woven bone : it has high cellularity, a rapid formation rate
(30 µ/day or more), relatively low mineral density, high
random fiber orientation an poor strength. It serves an
important stabilization role in postoperative healing of
endosseous implants . During the initial healing process
woven bone fills all spaces at the bone-implant interface.
Although capable of stabilizing an unloaded implant, woven
bone lacks the strength to resist masticatory function.

Lamellar bone is the principal load-bearing tissue of the adult
skeleton. It is the predominant component of a mature bone-
implant interface. Lamellar bone is formed relatively slowly (less
than 1.0 µ/day),has a highly organized matrix, and is densely
mineralized.
Composite bone is a combination of paravascular lamellar bone
deposited on a woven bone matrix.. Formation of composite bone
is an important step in achieving stabilization of an implant
during the rigid integration process

The healing potential for an implant is determined by three
factors:
(1) quality of bone at the site of implantation,
(2) postoperative stability of the implant,
(3) degree of integration of the interface.

If there is good postoperative stability of the implant in
cortical bone, the healing response involves six
physiological stages:
1. Callus formation (0.5 month)- initial,
2. Callus maturation (0.5 to 1.5 months),
3. Regional acceleratory phenomenon (RAP) - (1.5 to 12
months) remodeling of the non vital interface and supporting
bone ,
4. Osseous integration of the interface (1.5 to 12
months)completion of the RAP, increased direct contact of
living bone at the interface,
5. Maturation of supporting bone (4 to 12 months)completion
of the RAP, secondary mineralization of newbone and
increased direct contact of living bone at the interface,
6. Long-term maintenance of osseo integration .

Biology of osseointegration.
Hematoma
Callus formation

Bone remodeling
Fibrous tissue

 Dr .J.B.cope proposed classified othodontic TAD into two types :

INDICATIONS
AND
CONTRAINDICATIONS

TREATMENT PLANNING
Problem List and Patient Desires
Initial Evaluation
Chief compliant
Medical/ Dental History Review
Intra /Extraoral Examination
Diagnostic Impression /Articulated Casts
Radiographs (Panoramic and Periapical ,CT Scan or Tomography
Photographs
Treatment Options / Informed Consent

TREAMENT CONSIDERATIONS
Suitability for implants
 Quantity and quality of the bone
 Age of the patient
 Reason behing their seeking implant placement.

1)Bone.
Bone quantity and extent of ridge resorption are important factors to assess.
2) Age of the patient.
Age of the patient is an important consideration, as implants are problematic
if inserted in growing children for the following reasons,
1.The use of palatal implants in anterior maxilla contraindicated because of
midpalatal suture being open.

 2.Resorption from the posterior part of the maxilla resulting from growth
changes, could lead to exposure of implant into sinus.
 3.Posterior part of the mandible continues to undergo growth changes in all
the planes of space ,and such as definitive implant placement in these
area difficult to estimate.
 4.Even when growth is complete and teeth appear fully erupted
,infraocclusion of Implants supported crowns may occur. This is result of
minimal continued eruption of adjacent teeth, post adolescence, and is
most frequently seen with upper lateral incisors.

Teeth- Number & Existing Conditions
1.Size shape & diameter of existing dentition.
2. Tooth & root angulation & proximity.
3.More than 1.5 mm space between implant and natural teeth.
Periodontium
Bone support :
Quality – Best is the thick compact cortical bone with core of dens
trabacular cancellous bone .
Quantity – 6mm buccal – lingual width with sufficient tissue volume

The predictable use of implants as a source of orthodontic and dentofacial
orthopedic anchorage requires a practical understanding of the fundamental
principles of bone physiology and biomechanics. However, a careful
evaluation of prospective patients is indicated because many candidates for
implant-anchored orthodontics are affected by osteopenia, osteoporosis, or
other medical problems. Optimal use of osseointegrated implants requires a
thorough knowledge of bone biomechanics, particularly when the patient is
skeletally and/or periodontally compromised .

An evaluation of bone metabolism is a key element of the
diagnostic workup. The minimal screening procedure involves a
careful medical history, evaluation of signs and symptoms of
skeletal disease and an assessment of risk factors associated with
negative calcium balance.
The most prevalent metabolic bone diseases in middle-aged and
older patients are:
Renal osteodystrophy-poor bone quality (fibrous dysplasia) that
is secondary to inadequate kidney function .
Hyperparathyroidism-elevated serum calcium is often associated
with high-turnover osteopenia (low bone mass) secondary to a
parathyroid adenoma .
Thyrotoxicosis-high bone turnover leading to osteopenia,
associated with hyperthyroidism or overtreatment of
hypothyroidism .

Osteomalacia - poor mineralization of osteoid due to
deficiency of the active metabolite of vitamin D
(I, 25-dihydroxycholecalciferol) .
Osteoporosis-usually defined as symptomatic osteopenia ;
most common fractures are of the spine, wrist, and/or hip.
Fragility of other weight bearing joints such as the knee and ankle are also
common problems.

Mucogingival problems
Suffient volume is necessary
Soft tissue heights of <2mm or> 4mm may present a challenge
Oral hygiene
Important pre and post implant placement
Systemic manifestations
1.Diabetics are predisposed to delayed healing
2. Destructive habits – smoking is contraindicated to placement of implant as
delayed or inadequate tissue healing and osseo intergration is noted
Radiographic analysis
Periapical pathology
Radiopaque/radiolucent regions above the inferior alveolar region or below the
maxillary sinus.
Adequate space above IAN or below maxillary sinus
Implant should be placed at a minimum of 2mm from the inferior alveolar cana
or below the maxillary sinus
Adequate inter radicular area.
Bone quality and quantity. Dr Ravikanth Lakkakula

Sites of the implants

maxilla
BELOW NASAL SPINE
PALATE
INFRAZYGOMATIC
CREST

RETROMOLAR AREA
AND MOLAR AREA
ALVEOLAR PROCESS
SYMPHYSIS
Mandible

Blue -- safe zone
red -- danger zoneDr Ravikanth Lakkakula

maxilla

Implant as a absolute anchorage

Classification of anchorage
1.resiprocal anchorage.
2.muscular anchorage.
3.anchorage preparation : tip back and toe – in
4.splinting anchorage.
5.intermaxillary anchorage.
6.extraoral anchorage.
7.cortical anchorage.
8.extraoral anchorage.
9.absolute anchorage.

1.Resiprocal anchorage
 It is depending upon
1.position,tipping,rotation of tooth
2.radicular size.
3.radicular space(dilacerations etc)
4.periodontal support
5.crown condition
6.root condition
7.it can be – mesiodistal,labiolingual,intrusion or extrusion.

2. Muscular anchorage
 It is depending upon
1.lips and cheek strenght.
2.habits such as lips ,cheek, tongue trust.
3.mandibular elevating muscular strenght type.
4.cusps integrity.
5.presence or absence of antagonist teeth.

3.Anchorage preparation toe-in and tip back.
 Anchorage preparation is achived by incorporation of toe in
and tip back bends in archwires. sagittal curve(pronounced
curve of spee in the maxilla or inverted curve of spee in the
mandible(ovoid shape) Responds to toe-in and tip back
respectively.
 Anchorage preparation in lingual technique same as
Far as saggital curve is concerned,but it is other way around
as far as horizontal curve is concerned,also archwire must
curve towards the labial.(toe-out curve)

4.Cortical anchorage
It is depends upon
1. radicular position with respect to cortical bone.
2. alveolar border narrowing in edentulous space.
3. It is increase with age due to decrease of blood circulation.

5.Splinting anchorage
 It is usually done with figure of 8 with ligature wire,
Depends upon
1.Number of splinting teeth.
2.Radicular Size and shape of splinting teeth.
3.Periodontal support of splinting teeth.
4.Presence of fixed prosthesis(bridges).
It offers only mesio-distal anchorage.

6.Intermaxillary anchorage
 Inter maxillary class 2 ,class 3 oblique , vertical and cross elastics used as
inter maxillary anchorage.
 There are many appliances(functional appliances, appliances with occlusal
guide. etc)and fixed (herbest ,twin force, jasper jumper) also used.

7.Extraoral anchorage
1.inverse chin cup.
2.facemask.
3.facebow.

8.Anchorage appliances
1.goshgarian trans palatal arch.
2.Expansion appliances
-quad helix
-bi-helix
-separation appliances etc
3.Distalisation appliances-pendulum
4.Nance appliances
5.Lingual or palatine arch
6.Lip bumper.

9.Absolute anchorage
1.microimplants
2.miniplates
3.zygomatic ligatures
4.conventional implants
5.ankolysed teeth
6.palatine implants
7.onplants.

 There are two basic forms of absolute anchorage
Direct anchorage : when active segment is pulled directly from
microimplant.
Indirect anchorage : when active segment is pulled from the reactive
segment, and this segment is fixed to microimplant to incrase anchorage.

Anchorage is a “resistance to unwanted tooth movement ” ---
proffit
*Group A :- more than 75% of the extraction space is required
for retracting the anterior segment.
* Group B :- describes symmetrical space closure with equal
movement of the anterior & posterior teeth to close the space.
* Group C :- this is a category of non- critical anchorage wherein
75% of the space closure is achieved by mesial movement of
the posterior teeth.

Methods of Anchorage control
Conventional
Extra oral Intra oral
Head Gear Dental anchors

Problem with Conventional anchors
• Head gears require patient compliance so as to be an effective
source of anchorage. If the patient is not co-operative enough with
the treatment, anchorage preservation becomes a difficult issue to
tackle.
&
• There are also many reported cases of Head gear injuries.

While problems with dental anchors are that, the anchor units experience
a reciprocal effect of the forces applied to move the remaining teeth to
their optimal positions – thereby tending to move towards the direction of
the force applied. Therefore skeletal anchorage through implants is
chosen to limit the extent of detrimental, unwanted tooth movement.
The paradigm shift is the usage of implant as skeletal anchors to overcome
the problems of conventional anchors.

Differece between
conventional
and
implant anchorage

Surgical procedure

equipments
 General armamentarium
Basic set of dental instruments
sterile tray cover
sterile suction tips
anaesthesia : local and topical gel
 Instruments for self cutting mini screws
mucosal biopsy or soft tissue punch
Rotary drill
Pilot drill
Elbow or contra angle hand piece
Hand driver or dental hand piece driver for mini screw.

Direct method

Anchor pro x-ray guide
Pilot drill Short and long screw driverDr Ravikanth Lakkakula

Surgical implant Index
Prepare an acrylic jig in cold cure acrylic to fit the occlusal surfaces of adjacent
teth 0.9mm ss orthodontic wires.
Mark likely spot on soft tissue with methylene blue indeliable marker or
bleeding point.
Align tip of jig wire to this point .
IOPA X-ray with jig to determine suitability of site.
ACRYLIC SURGICAL INDEX RADIOGRAPHIC EVALUTION

Indirect method

 Surgical procedure for orthodontic implants should be placed on following
principles,
1)aseptic principle.
2)atraumatic principle.
3)thorough preoperative examination and precise implant positioning.
4)premedication for pain control.
5)standerised procedure.

Aseptic principle

Atraumatic procedure
 Necrotic bone should be removed to promote the healing of
the bone tissue. it is essential to minimize trauma during
implant placement to allow favorable healing ,because the
necrosis of the osseous tissue inevitable.

 To promote standardized process, the surgical procedure divided into
1) preoperative examine stage.
2) marking stage.
3) perforating stage.
4) guiding stage.
5) finishing stage.

Perporating stage
There are two ways by which perporate through cortical bone :
1. use of surgical drill.
2.use of an implant.
Implant is inserted perpendicular to the surface is recommended to prevent
slippage on the surface.
The slope of osseuoss tissue should be determined by palpation at earlier
stage.

Possible causes of implant failure
1.infection : the surface of microimplant should be contaminated.
2. hygiene of the patient : tooth brushing and illutories.
3.avoid overload, the pull direction should be perpendicular as possible to the
axial direction of implant.
4. microimplants are designed to support 450grams
but it is better to use forces under 300grams.

5.Microimplant mobility provokes inflammatory response to adjacent teeth. If
mobility appears, remove and reinsert again same other site.
6.insufficient penetration into bone. (not less than 4-5mm not counting the
soft tissue thickness)
7.Oblique insertion angle offers more retention than perpendicular insertion
angle, but because it offers a wide contact angle between micro implant
and cortical bone. it should be taken account osseo integration should not
take place.

8.Failure to disinfect the area before insertion.
9.Too much heat during insertion due to high velosity.
excessive pressure or abscence of irrigation.
10.poor quality of bone and poor density.
11.dry mouth and inflammation.
12.smoker.
13.poor oral hygiene.
14.contact of implants with adjacent roots.

prevention of complications and failures
1.use tapered microimplants.
2.Use a large diameter as possible ,but not smaller than 1mm
3.try to insert micro implants through attached gingiva.
4.Do not press micro implants while inserting them to avoid its fracture.
5.Usually,a long screwdriver will be used in labial zone and a short
screwdriver in palatine zone. it is recommendable to tie up the short
screwdriver to avoid accidents such as its swallowing.

6.Avoid oscillatory movements when inserting microimplants to avoid
perforating larger diameter into the bone than needed,which than would
not serve to retain microimplant. special attention should be paid when
perforating palatine surface due to tongue pressure or in labial distal zone
,due to labial commissure tension.
7.check inter radicular space before insertion of micro implant.
8. if there is too much resistance offered when trying to insert micro implant
,repeat drilling using thicker bur.
9.measure adequately the mucosa thickness to determine microimplant’s
lenght. microimplant should penetrate into the bone 4-5mm as minimum.

10.use bur that has a diameter of 0.3-1mm smaller than diameter of
microimplant which will depend on the quality of the bone, to perforate the
cortical bone, especially in zones where cortical bone is very thick.
11.if closed coil spring or elastic chain is used, check if they do not press the
mucosa and if necessary, insert a buffer to avoid its invagination into
mucosa.

Prevention of microimplant deformation and fracture.
 In case that a significant resistant is encountered when
screwing microimplant ,it is recommendable to perforate the
cortical bone with a bur that has smaller diameter than
microimplant . Special screwdriver have been designed with
force controllers which avoids microimplant fracture.

Prevention of peri microimplantitis
 By avoiding the infection and avoiding the to overload of microimplant.
It is important to take following precautions
 Surgical technique : disinfection of surgical field sterilisation of
instruments and microimplants ,maitainance of sterilisation according to
aseptic norms, not contaminating microimplants during insertion.
 Hygiene of the patient : recommended buccal irrigators ,careful
teethbrushing.etc.

 The risk is increased in smokers and mouthbreathers.
 Force intensity : it should be less than 300grams buy force
used in orthodontics is less than 200 grams.
 Force should be as perpendicular perpendicular to
microimplant direction as possible.at least it should be tried
not to exert axial force.

DIFFERENT TYPES OF MICROIMPLANTS

Different companies of miniscrews

Number of miniscrews in the delivery program of
different companies.

Different head designs

The diameter of the trans gingival collar in relation to diameter of the head.
To avoid inflammation around the screw (perimucositiis), it is recommended that the
diameter of the head should be smaller(A) or equal (B) to the diameter of the head.
The gingiva around the screw is difficult to clean if the gingiva is covered by part of
the miniscrew(c).

Screw with design
type
indication Coupling elements advantage
ball or triangular
head
Mesial and distal
translations with
restrictions, space
closure and
intrusion.
Elastic chain,
tension and coil
springs, round
wires.
Most coupling
elements can be
easily applied.
Orientation of ball
head in contrast to
screw with hooks is
not necessary.
Eyelets or holes Mesial and distal
translations with
restrictions, space
closure and
intrusion.
Round
wires,tension
springs and elastic
chains.
No advantage
compare to either
hook or ball head.

Single slot Uprighting,intrusion
,extrusion,
Mesial and distal
translations
Square and
rectangular wires ,
tension springs and
elastic chains.
Square and
rectangular wires
can be used.
Cross slot Uprighting,
intrusion, extrusion,
Mesial and distal
translations
Square and
rectangular wires ,
round wires,tension
springs and elastic
chains.
The head design has
added advantage of
permitting the in
corporation of
Square and
rectangular wires
for indirect
applications that
open new horizon
in biomechanics for
Advanced users of
miniscrews.
hooks Mesial and distal
translations with
restrictions, space
closure and
intrusion.
Elastic chain,
tension and coil
springs, round
wires.
Most coupling
elements can be
easily appiled.

Different head designs--companies

Comparision of shanks

Comparision of self drilling and self tapping thread.

APPLICATIONS

APPLICATION OF IMPLANT IN ORTHODONTICS
As a Source of Anchorage alone (Indirect anchorage)
a. Orthopedic Anchorage
- Maxillary Expansion
- Headgear like effects
b. Dental Anchorage
-Space closure of anterior teeth
-Intrusion of posterior teeth
-Distalization
c. In conjunction with prosthetic rehabilitation (Direct
anchorage).

ORTHOPEDIC CORRECTION WITH IMPLANTS
i) Maxillary Protraction
ii) Maxillary Expansion.
However, these have been in experimental studies.
i) Maxillary Protraction.
Smalley et al in 1988 used Branemark implants into the maxilla, zygoma, orbital and
occipital bones of monkeys. A force of 600 gm was delivered to maxillary and
zygomatic bones . A 12mm widening at the zygomaticomaxillary suture was seen and
16mm widening at zygomaticotemporal suture was observed. The dental changes seen
were a 5-7mm change in overjet . However dental tipping also occurred along with
skeletal protraction.

ii) Implants for skeletal expansion
In 1995 - Movassaghi et al tested fronto nasal suture expansion in rabbits from an
implanted titanium screw device. The plates were placed in frontal and nasal
bones. After 4 weeks of healing, 55 gm force was applied . Force was applied for 5
weeks and a significant increase in growth to the tune of 6 mm across frontonasal
suture was seen.

In 1997 Andrew Parr et al conducted experiments on
Midnasalexpansion using endosseous titanium screws. They
divided the sample into 3 groups- 1 control and 2
experimental groups. 1 Nand 3N loading forces were
applied in the two experimental groups. Their results
showed a 92% stability of implants. Sutural expansion of
5.2mm and 6.8 mm respectively was seen in the 1N and 3N
load categories. Mineral apposition and bone formation
rates were significantly higher in the experimental group.
The 3N group showed more expansion but this did not
affect the rate of bone formation across the suture

ENDOSSEOUS IMPLANT
Implants for dental anchorage
a) Implants for intrusion of teeth
Creekmore in 1983 published a case report of usage of a vitallium implant for
anchorage, while intruding the upper anterior teeth. The vitallium srew was
inserted just below the anterior nasal spine . After an unloading period of 10
days, an elastic thread was tied from head of the screw to the arch wire. Within
one year, 6mm intrusion was demonstrated along with lingual torque .

Another study by Southard in 1995 compared the intrusion 'potential of implants
with that of teeth (denta1 anchors). Titanium implants were placed in extracted
4th premolar area in dogs, followed by an unloading period of three months.
Then, an intrusive force of 50-60 gm via 'V' bend was effected. This was
compared with intrusive potential of teeth on the other side using the same
mechanics. No movement of implant was seen at the end of the experiment
whereas, on the other side, the tooth acting as the anchor units tipped severely.
Therefore, implants are definitely superior to the teeth acting as anchor units.

b) Implants for space closure
Extensive research relating to usage of retromolar implants for orthodontic
anchorage has been done by Eugene Roberts.
The first clinical trial was on an adult wherein an atrophic extraction site had
to be closed. A special implant was developed of size 3.8mm width and 6.9
mm length, which was placed in the retromolar area. A 0.021" X .025" SSwire
was used for used for anchorage from the screw around the premolar bracket .
The extraction spaces were closed using forces from buccal as well as the
lingual sides by activating the lingual arch. The premolar was prevented from
moving distally with the help of 0.021 X .025" wire acting as an anchorage.
The modification in this technique as suggested by him in 1994 includes the
usage of a .019" X.025" TMAwire ---This wire is termed as the anchorage
wire.

A Patient before treatment, showing missing mandibular first molar
with mesial tipping of second and third molars into extraction site.
B. Beginning of active treatment, with anchorage wire In place.
C. Molars translated mesially with no appreciable distal movement of
premolars.
D. Five months after active treatment, 9 mm of mesial translation of
mandibular molar root apices. Dr Ravikanth Lakkakula

Although the retromolar implants popularised by Eugene Roberts are very
efficient in preserving anchorage, they suffer from certain drawbacks, which
in turn has hindered their acceptance in routine clinical practice.
DISADVANTAGE OF RETROMOLAR (ENDOSSEOUS) IMPLANT.
The important limitations are :
a) Bulkiness of the implant and therefore the non suitability of placement in
the inter-dental areas.
b) It involves a two stage procedure and therefore a long waiting time before
loading the implant.
c) Anatomical limitations - such as erupting teeth, nerve canal etc. also add to
their minimal usage.
d) Cost of the implants - These are the root form implants used for tooth
replacement and therefore, very expensive.
.

SUBPERIOSTEL IMPLANT
THE ONPLANT
This is a classic example of a sub periosteal implant in Orthodontics , Developed by
Block and Hoffman in 1995, this system consists of a circular disc 8-10 mm in diameter
with a provision for abutments in the center of the superficial surface . These abutments
would enable the Orthodontist to carry out tooth movement against the Onplant. The
undersurface of this Titanium disc is textured and coated with Hydroxyapatite (HA). The
Hydroxyapetite ,being bioactive helps in stabilisation of the implant by improving
integration with bone. The average thickness (height) of the implant is 3 mm .
Lateral view
Different shapes
Internal surfaceDr Ravikanth Lakkakula

Method of Placement:
The onplant is placed by a surgeon through a specialised procedure known as
Tunneling. After making an incision in the posterior region of the palate, a sub-
periosteal tunnel flap is created extending till the desired location, using an
elevator. Care is taken to position the onplant as close to the midline as possible.
The onplant is not disturbed for a period of 3-4 months to allow bio-integration.
Later, the superficial surface of the onplant is exposed using a trephine and the
desired abutment is then threaded on.
Various head designs

Studies on Onplants:
Extensive animal studies have been carried out on onplants. They point out to the
fact that onplants bio-integrate and can tolerate a maximum force of 16 Ibs(1 pound
= 450 grams). Block and Hoffman further suggest that these onplants could be used
not only for dental anchorage; for eg: retraction of anteriors or distalising
posteriors, but also for orthopedic traction. Human trials are however, limited.
Disadvantages of Onplants:
a) A long waiting period prior to orthodontic force application.(3 months -
osseointegration)
b) Excessive surgical intervention - Two surgeries are necessary after onplant
placement; one to uncover the onplant cover screw and the other to remove the
onplant itself following Orthodontic treatment.
c) Cost factor.

OSSEOUS IMPLANT
Osseous implants are those that are placed in dense bone such as the zygoma ,the
body and ramus area or the mid-palatal areas. The implant systems under this
category are the
1.Skeletal Anchorage system,
2. Graz implant supported system ,
3. Zygoma anchorage system .

SKELETAL ANCHORAGE SYSTEM
The skeletal anchorage system was developed by Umemori and Sugawara.
Appliance design
It essentially consists of titanium miniplates, which are stabilised in the maxilla
or the mandible using screws. The earlier of these miniplates were the
conventional surgical mini plates, which are used by Oral Surgeons for rigid
fixation. The recent versions of these miniplates have been modified for attaching
orthodontic elastomeric or coil springs.
Different designs of miniplates are available and this fact offers some versatility
in placing the implants in different sites. The 'L' shaped miniplates have been the
most commonly used ones, while the 'T' shaped ones have been proposed for
usage while intruding anterior teeth . The screws used for fixing the miniplate are
usually 2-2.5mm in diameter

Method of Placement
Titanium miniplates were implanted after a local anesthesia with intravenous
sedation. First, a mucoperiosteal incision was made at the buccal vestibule
directly under the first or second lower molars. The mucoperiosteal flap was
then elevated, and the surface of the cortical bone at the apical region of the
molar was exposed.
An L-shaped miniplate was adjusted to fit the contour of each cortical bone
surface and was fixed by bone screws (length, 5 mm or 7 mm) with the long
arm exposed to the oral cavity from the incised wound (there are two holes in
the long arm of the miniplate; the exposed hole will be used to directly receive
the intrusive force).
The implant was placed such that it did not interfer with mandibular
movement.. All of the miniplates were transfixed at the region of the buccal
vestibule. Loading was done after wound is healed.

Advantage of miniplates
The shape of the miniplate can be adjusted to the type of tooth movement:
i.e,
intrusion of molars, intrusion of incisors, distalization or protraction of teeth,
etc., and the thickness of the patient’s bone.
Position of the plate can be adjusted during the treatment .
It can be placed without destroying the teeth or bone
The anchor plates are monocortically placed at the piriform opening rim, the
zygomatic buttresses, and any regions of the mandibular cortical bone. The
anchor plates work as the onplant and the screws function as the implant, SAS
enables the rigid anchorage that results from the osseointegration effects in both
the anchor plates and screws
All portions of the anchor plates and screws are placed outside the maxillary
and mandibular dentition, so the SAS does not interfere with tooth movement

Distalization of molars
It is possible to distalize the mandibular molars with anchor plates placed at the
anterior border of the mandibular ramus or mandibular body. Distalization of the
mandibular molars enables the clinician to correct anterior crossbites, mandibular
incisor crowding, and mandibular dental asymmetry without extracting premolars.
single molar distalization
Extraction of the third molars is done to create the space for the molar distalization.
After the buccal segments are leveled and aligned, stiff archwires . L-shaped anchor
plates are placed at the anterior border of the mandibular ramus. Then the bands or
brackets of the first molars are taken off, and a retractive force is applied to the second
molars with an open coil spring. To avoid the side effects of the reciprocal coil spring,
the first premolars must be firmly ligated with anchor plates . After the distalization of
the second molars, distalization of the first molars is done with the same procedure.

En masse distalization of the entire buccal segments.
Direct retractive force is applied from the anchor plates to the first premolars to
perform en masse distalization of the buccal segments. Elastic chains or
nickeltitanium closed coil springs usually provide the retractive orthodontic
force.

Intusion of lower molar for correction of open bite.
Intrusion of the lower molars was achieved with the application of elastic orthodontic
force on the SAS , Lingual crown torque was applied to the lower molars with Burstone’s
precision lingual arch to avoid buccal flaring during intrusion .

A) L-shaped miniplate for intrusion of molars
B) L-shaped for distal movement of molars
C) Y-shaped intrusion and distalizaton of maxillary molars
D) Straight miniplate for intrusion of molars

ADVANTAGE OF SAS
The SAS enables tooth movement to be controlled 3-dimensionally, so that
treatment goals can be accomplished, even when the amount of tooth
movement required is more than the mesiodistal width of the premolars.
SAS, it is not always necessary to extract the mandibular first or second
premolars, even in patients with moderate to severe crowding.
The molar relationship in patients with symmetric or asymmetric Class III
molar relationships can be corrected without having to extract mandibular
premolars

ZYGOMA ANCHORAGE SYSTEM( ZAS )
Hugo De Clerck and Geerinckx of Belgium introduced this system in 2002.
Appliance design
The upper part of the Zygoma Anchor is a titanium miniplate with three holes, slightly
curved to fit against the inferior edge of the zygomaticomaxillary buttress . A round bar,
1.5mm in diameter, connects the miniplate and the fixation unit. A cylinder at the end of
the bar has a vertical slot, where an auxiliary wire with a maximum size of .020 can be
fixed with a locking screw.
The plate is attached above the molar roots by three self-tapping titanium miniscrews,
each with a diameter of 2.3mm and a length of 5mm or 7mm. The miniscrews do not need
to be sandblasted, etched, or coated. Square holes in the center of the screw heads
accommodate a screw-driver for initial placement, while pentagonal outer holes are used
to remove the screws at the end of treatment.

Method of Placement
To place the anchor, an L-shaped incision, consisting of a vertical incision mesial to
theinferior crest of the zygomaticomaxillary buttress and a small horizontal incision at
the border between the mobile and attached gingiva, is made under local anesthesia. The
mucoperiosteum is elevated, and the upper part of the anchor is adapted to the curvature
of the bone crest . Three holes with a diameter of 1.6mm each are drilled, and the
Zygoma Anchor is affixed with the three miniscrews. The cylinder should penetrate the
attached gingiva in front of the furcation of the first molar roots at a 90° angle to the
alveolar bone surface. The miniplate is covered by the mucoperiosteum
and sutured with resorbable stitches.

CLINICAL APPLICATION
Orthodontic forces can be applied to the anchor immediately after implantation. To
connect the Zygoma Anchor with the anterior teeth, a rigid power arm was designed to fit
in the large vertical slot of a canine bracket .The hook at the end of the power arm is
situated at the level of the canine’s center of resistance. A nickel titanium closed-coil
spring with a force of 50-100g is attached between the power arm on the canine and the
Zygoma Anchor, so that the direction of force is parallel to the main archwire

ADVANTAGE
1. Miniscrews are small enough to be placed between the roots of the teeth in the
alveolar bone.By connecting two or more miniscrews, the orthodontic reaction
forces can be neutralized.
2.The surgical procedure is uncomplicated because the screws are placed directly
through the gingiva, without a mucoperiosteal flap, and can be loaded
immediately after insertion.
3.Miniscrews can be used in the anterior or posterior region and attached with
elastics or coil springs to the fixed appliance for direct anchorage.
4.Anchorage can be adapted to changing treatment needs in different parts of the
dental arches.

DISADVANTAGE
The main disadvantage of these screws is their proximity to the roots, which may be
damaged during placement of the screws or when the adjacent teeth are displaced
5.The ZAS uses three miniscrews, increasing total anchorage over other types of
implants.
6.The point of application of the orthodontic forces is brought down to the level of
the furcation of the upper first molar roots.
7.The vertical slot with the locking screw makes it possible to attach an auxiliary
wire, which can move the point of force application some distance from the anchor.

ORTHOSYSTEM IMPLANT
Developed by Wehrbein, this is a titanium screw implant with a diameter of 3.3
mm inserted into the median palate or the retromolar regions of the mandible or
the maxilla . The implants are surface treated with sand blasting and acid
etching for reducing to improve integration. They are available in two sizes of 4
mm and 6 mm length. An 8 week waiting period has been suggested before
applying forces onto this implant.

GRAZ IMPLANT SUPPORTED PENDULUM
Graz implant supported system introduced by Karcher and Byloff, this anchorage
system consists of a modified titanium miniplate, with provision for four miniscrews,
and two oval shaped cylinders. This was used mainly as a support for the Nance button
of a pendulum appliance in the palate . This system can be loaded within 2 weeks to
distalize and anchor maxillary first and second molars ..

Appliance Design
It consists of a simple surgical plate (15 X 10 mm) . Two cylinders (10 mm long and
3.5 mm in diameter) are soldered at right angles to the center of the
plate. The plate is fixed to the palatal bone via four 5-mm-long titanium miniscrews.The
2 cylinders perforate the palatal mucosa to enter the oral cavity .The entire anchorage
device is constructed of 100% titanium. No auxiliary wires are bonded to the premolars,
making the GISP removable . In the palatal portion of the resin body are 2 cylindric slots
that correspond to the 2 cylinders . The system is based on a telescopic principle:the 2
slots of the removable pendulum (RP) are placed over the 2 fixed cylinders of the
implant .

CLINICAL APPLICATIONS
Surgical placement and orthodontic procedure
The surgeon exposes the anterior part of the palate for insertion of the anchorage plate by
preparing a mucoperiosteal flap . If third molars are removed at the same time, the
procedure is carried out under general anesthesia. The titanium plate with the 2 cylinders
is fixed via four 5-mm-long titanium miniscrews to the bony palate in the median palatal
area.

The plate can be positioned so that the cylinders are positioned either mesiodistally
along the palatal suture, or one to the right and one to the left (i.e, rotated 90degrees).
The area is then covered again with the flap, which has been incised to let the 2
cylinders pass through.
After 1 to 2 weeks of healing, an impression is made of the maxillary arch
and the palate , and a plaster model is made of the maxilla and titanium cylinders. The
removable Pendulam Appliance is fabricated in the laboratory and then placed onto the
2 cylinders in the patient's mouth.

The TMA springs are extraorally activated prior to insertion to generate approximately 250
g of force at a 45-degreeangle . The Removable Pendulum is then slid onto the 2 cylinders ,
and the 2 TMA springs are introduced into lingual sheaths on the maxillary first molars. At
the same time a 0.020- inch stainless steel round sectional wire is inserted into the tubes on
the first and second molars. A nickel-titanium alloy (Ni-Ti) push-coil distalizes the second
molar with approximately 100 g of force. Once the second molar is sufficiently distalized,
the force of the push-coil is reduced to be barely active. The TMA spring of the Removable
Pendulum is then stronger than the passive push-coil between the first and second molar. In
this way the first molar is more effectively moved distally, since the force of the distalizing
force is focused primarily on it, while the second molar is kept in the desired position.

Advantages of Osseous implants:
The osseous implants, specially the mini plate designs offer the Orthodontist a fair
chance of success in effecting complex tooth movements such as molar intrusion.
True intrusion of upper and lower molars in moderate anterior open bite cases converts
a borderline orthognathic case into an orthodontic one. This emerging new area of
implant application has been termed as 'Orthognathic Orthodontics limitations of
Osseous implants:
Disadvantage
1. They need a fairly complex surgery and therefore have to be placed by a surgeon.
2. The chances of infection are greater than the screw implants.
3. Their removal is as difficult as the placement .

INTERDENTAL IMPLANTS
These implants are endosseous implants but of smaller diameter, which allows
placement in interdental areas. They rely more on mechanical retention than complete
osseointegration .They are favored over the retro molar implants due to the
following reasons:
a) Placement is very simple and can be done under L.A.
b) They seem to be equally effective in resisting forces as the larger root form
implants.
c) They can be used for bringing about all types of tooth movement .
d) Removal is an uneventful procedure .

Molar uprighting
A micro-implant (1.2mm in diameter, 12mm in length) was placed in the maxillary
tuberosity. A longer microscrew was used than in the lower retromolar area
because the cortical bone is much thinner in the maxillary arch than in the
mandibular arch. After two weeks of healing, 70g of force was applied with
between the microscrew and lingual cleats on the buccal and lingual surfaces of the
second molar . Four months later, the second molar showed considerable uprighting

A micro-implant (1.2mm in diameter, 8mm in length) was placed in the retromolar
area distal to the second molar, and a ligature wire was extended outward for
elastomeric force application . To avoid root damage, only 50g of orthodontic force
was applied . The molar was uprighted after eight months of treatment, and bracket
was bonded to it for further movement.

SPIDER SCREW
The Spider Screw is a self-tapping miniscrew available in three lengths--7mm, 9mm,
and11mm--in single-use, sterile packaging. The screw head has an internal .021" ×
.025" slot, an external slot of the same dimensions, and an .025" round vertical slot.

It comes in three heights to fit soft tissues of different thicknesses:
A . regular, with a thicker head and an intermediate-length collar;
B . low profile, with a thinner head and a longer collar; and
C . low profile flat, with the same thin head and a shorter collar .
All three types are small enough to avoid soft-tissue irritation, but wide enough
for orthodontic loading. The biocompatibility of titanium ensures patient
tolerance, and the Spider Screw's smooth, self-tapping surface permits easy
removal at the completion of treatment.
Applied forces can range from 50g to 200g, depending on the quality of the bone
and the orthodontic movement desired

MINISCREW ANCHORAGE SYSTEM(M.A.S)
Developed by Incorvati ,Carano and et al
Appliance design
The screws used in the M.A.S. system are made of medical grade 5 titanium, they have a
conical profile and are available in three diameters.
Type A ----- has a 1.3 mm diameter at the height of the neck of the implant, and 1.1 mm at
the tip.
Type B ------has a 1.5 mm diameter at the neck and 1.3 mm at the tip.
The overall length for both Type A and Type B is 11.0 mm.
Type C ---------has a 1.5 mm at the neck and 1.3 mm at the tip with 9mm of total length.

The head has a shape of two spheres ( 2.0 mm the lower sphere and 2.2mm the
upper) that are fused together, with an internal hexagon for the insertion of the
screw driver. There is a 0.6 mm aperture placed perpendicular to the length of the
screw where a ligature wire or auxiliary monkey hook can be attached. In the
junction point between the two circles, a slot is present for the attachment of
elastics, chains or coil springs .

ADVANTAGE OF MINISCREW ANCHORAGE SYSTEM:
. Independency from the number or position of the present teeth
. Optimal use of the pulling forces.
. Independency from patient cooperation.
. Patient comfort.
. Shorter treatment time .(not need to prepare dental
anchorage).
. Easy and fast screw insertion.
. Possible application even in interceptive therapy .
Advantages when compared with other osteointegrated systems:
. VersatiIity in the insertion sites
. Easy insertion and removal
. Immediate loading
. Application in growing patients
. Lowcost

CLINICAL APPLICATION
Closure of Space
For posterior space closure the anterior-posterior location of the miniscrew is between
roots of the first molars and the second bicuspids roots.
Vertically the miniscrew should be located at or above the mucogingival line depending
on the desired line of action.
For intrusion and distalization –above the mucogingival line.
For retration movement –at level of the mucogingival line.
Higher the screw in the maxilla the more perpendicular ,it is inorder to avoid damage to
the maxillary sinus .Ideally it is 30- 40 degrees .
In case the alveolar process is to prominent an auxillary attachment (monkey hook) is
used it avoids discomfort and possible ulceration of the gums.
In the mandibular arch care should be done to avoid the mental foramen.

Symmetric intrusion of the incisors
To intrude the upper incisors the screw is placed between the upper lateral incisors and
the canines. The placement of the mini-screws should be done after leveling and
alignment, in order to maximize the inter radicular space at the placement site.
In order to avoid tipping the upper incisors buccally during the intrusion, the end of the
archwire should be cinched back .

Correction of cant of occlusal plane
 The facial asymmetry is often associated with canting of
occlusal plane. the cant in the occlusal plane may compromise
the beauty, facial profile, with concurrent canting the lip line.
 The canted occlusal plane can be corrected with extrusion of
teeth on the side with more superiorly placed teeth, using
vertical elastics.
 The intrusion of the extruded side, however cannot be achived
with coventional orthodontic mechanics.

 The microimplant can be placed in buccal alveolar bone can
apply intrude force to the posterior teeth, and can be used to
correct the canted occlusal plane.
 During the intrusive movements, it is very important to center
the mini-screws in between the roots of the teeth that need to
be intruded in order to avoid the interferences between the
teeth and the screw.

Molar intrusion
 The extruded molar required pure molar intrusion along the
long axis the tooth without extrusion of the adjacent teeth.
 The c-res of the upper molar is expected to be at the center of
the occlusal table , close to the palatal root.

The recommended insertion points are mesial interdental area
of the buccal surface and distal interdental area on the
palatal side, or viceversa.

 In this way a combined buccal and palatal force can pass
throught the c-res .
 Additional miniscrews are placed either side of the alveolar
slope to increase the adjustability of the force direction.
 three or four miniimplants are useful to prevent or correct the
tipping of the molars .

Enmass anchorage loss(molar mesialisation)
 To avoid mesioinclination of posterior teeth and retroinclination of anterior
teeth during molar mesialisation ,mechanics are followed
 A long hook is welded to the first molar band and microimplant is inserted
from distal from the canine in the c-res ,in this way molar can be moved
mesially without side effects.

Intermaxillary anchorage
Class II correctionis done by elastics or anterior repositioning appliances (i.e.
Jasper Jumper, Bite Fixer, etc. There are numerous unwanted side effects of
those kinds of mechanics, such as excessive anterior movement (proclination
and protrusion) .
To address the above problems one alternative may be to place MAS between
the roots of the first and second lower molars or between the root of the second
bicuspids and lower first molars, in this way the upper arch can be retracted
without any unwanted dental effects on the lower teeth.
The placement of the MAS mesial to the lower molar may also prevent the
mesial movement of the entire lower arch because the MAS, when in contact
with the lower molar, may not allow it to move anteriorly. More research is
needed to verify the clinical results.

Lingual orthodontics
 To facilitate and minimize the appliance.
 Minimize the friction.
 Minimize the requirements of patient co-operation.
 Minimize the force.
 Maximize the anchorage.

Asymmetric expansion

FUTURE OF IMPLANT(BIOS).
The ideal implant design would be one that would be simple to place as well
as remove, causing minimum discomfort to the patient. At the same time,
they should be optimum in resisting the conventional Orthodontic forces.
One would be looking at newer designs, which could be placed by an
Orthodontist himself. Also, since the implants need not last for a very long
time, biodegradable implants may be a lucrative option.
Biodegradable screws made of L-polylactide have been introduced by
Glatzmaier et al and are currentlyundergoing clinical trials. The system,
termed as theBIOS (Bioresorbabale implant for Orthodontic systems)consists
of resorbable polylactide with a metal abutment.

 The bio resorbable implant anchor for orthodontics system (BIOS)
implant is designed to provide orthodontic anchoring functions in
adolescents and adult patients, and to then be resorbed without a
foreign body reaction or signs of clinical inflammation.
 Shear strength and maximum vertical strength have been measured
in biomechanical in vitro tests. BIOS fixtures can be loaded with
horizontal shearing forces of 50 N with a mean deflection of
0.26+0.13 mm and mean vertical removal forces of 155+80 N.
 Clinical studies are currently being undertaken to evaluate clinical
practicability and biocompatibility of the BIOS implants.

CONCLUSION
Implants for the purpose of conserving anchorage are welcome
additions to the armamentarium of a clinical Orthodontist. They
help the Orthodontist to overcome the challenge of unwanted
reciprocal tooth movement. The presently available implant
systems are bound to change and evolve into more patient
friendly and operator convenient designs. Long-term clinical
trials are awaited to establish clinical guidelines in using
implants for both orthodontic and orthopedic anchorage.

Temporary anchorage devices in orthodontics

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