Implants in Orthodontics

 

IMPLANTS IN ORTHODONTICS INTRODUCTION Successful orthodontic treatment has always required intra oral anchorage with a high resistance to displacement. Extra oral traction can be an effective reinforcement, but demands exceptional patient co-operation. The size, bul, cost and invasiveness of  prosthetic !sseo integrated implants have limited their orthodontic application.

TERMINOLOGY • •

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 Anchorage: resistance to unwanted tooth movement.  Anchorage: resistance Temporary anchorage device" device" device that is temporarily fixed to the bone for the  purpose of enhancing orthodontic anchorage either by supporting the teeth of the reactive unit altogether, and is subsequently used.  Implant " a titanium device placed in the bone that replaces the root of a tooth and enables the attachment of prosthesis. Osseo integration" integration" the attachment of bone to the surface of an implant.  Immediate loading " a technique in which implants are restored, and thus, loaded at the time of their placement.

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Definition of orthodontic anchorage: •

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#n $%&' (ouis !ttofy defined anchorage as base against which orthodontic force or reaction of orthodontic force is applied. (ater, )asalogiannaes defined as *resistance to unwanted tooth movement+. )entists use appliances to produce desired movements of teeth in the dental arch.  ccording to ewtons third law of motion, every e very action has an equal and opposite reaction/ this means that, inevitably, other teeth move if the appliance engages them. nchorage is the resistance to the force provided by other teeth or devices. #n orthodontic treatment, reciprocal effects must be evaluated and controlled. The goal is to maximize desired tooth movement and minimize undesirable effects. E.0.ngle outlined anchorage as" Simple, Stationary, 1eciprocal, #ntra oral, #ntermaxillary or extra oral, it was summarized by !ttofy.  2oyers expanded !ttofys classification system simple 3 single, compound, and reinforced. 4ianelly and 4oldman defined the terms" maximum, moderate and minimum anchorage.  2arcotte and 5urstone classified as categories as , 5, 6. Tweed went on to describe anchorage preparation.

TEMPORARY ANCHORAGE DEICE enhancing cing TAD is a device that is temporarily fixed to bone for the purpose of enhan

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.

 

HISTORICAL PERSPECTIE •

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#n $%78, 4ainsforth and 0igley used vitallium v itallium screws and stainless steel wires in dog mandibles to apply orthodontic forces. 0owever, initiation of force resulted in screw loss. #n $%9%, (inow placed blade implants to anchor rubber bands to retract teeth but he never presented a long term results. $%97, 5ranemar et al observed a fixed anchorage of titanium to bone with no adverse tissue response. #n $%9%, titanium implants were stable over 8 years and osseointegrated in bone under light microscopy view. #n $%:7, 1oberts et al , corroborated the use of implants in orthodontic anchorage by using titatinum screws in rabbit femur. ;irst clinical report in the literature of the use of T)s appeared in $%:', 6reemore and Elund used a vitallium bone screw to treat patient with deep impinging overbite. CLASSI!ICATION

5iocompatible or 5iological in nature. 5oth groups sub classified according to manner in which they are attached to bone either biochemical <osseo integrated = or mechanical.   "ioco#$ati%&e TAD'

!sseo integration mechanical retention )ental implant palatal implant fixation screw fixationwire >alatal implant fixation screws wire?plates, mini screw implant 1etro molar implant "io&ogica& TAD' !sseointegration mechanical nylosed teeth dilacerated teeth I#$&ant' can %e ('ed in orthodontic') *ith fo&&o*ing reference': #mplants as a source of absolute anchorage   #mplants used for  anchorage and as abutments for restorations   •

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#mplant site preparation improved by orthodontics  #mplants in osteogenic distraction

I#$&ant' a' a 'o(rce of a%'o&(te anchorage   )uring active treatment, orthodontic anchorage aims to limit the extent of detrimental, unwanted tooth movement. There are methods available to reduce anchorage loss during treatment. 0owever, these techniques are often only partially successful, for example, transpalatal arches or headgear. The ability of  !sseo-integrated implants to remain stable under occlusal loading has led orthodontists to use them as anchorage units without   patient compliance.   Historical background  The concept of metal components componen ts being screwed into the maxilla  and mandible to

 

enhance orthodontic anchorage was first published  in $%78, with the use of vitallium screws to effect tooth movement in dogs. )espite some success, the resultant tooth   movement was limited due to the implants loosening within $ month of commencing tooth movement. Two decades later, (inow described the endosseous blade implant for   orthodontic anchorage, but did not report on the long-term stability. stability. @itreous carbon  implants showed a failure rate of 9A per cent when undergoing  orthodontic loading, and attempts at using 5ioglass-coated ceramic implants for orthodontic anchorage were almost as disappointing.  lthough all the above materials were compatible with bone,   none of them showed consistent long-term attachment of bone  to the implant interface, which means they did not achieve true osseo-integration.  Types of implants The rise in the use of dental implants has led to a great diversity  in their design and manufacture. The classification of implants can be based on their position, material of construction, or  design.  •

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The position of the implant can be subperiosteal, transosseous, or endosseous, the last of which is the most commonly used type  of dental implant.    Titanium is the accepted ideal material  for implant fabrication, but other variants     include gold alloys, vitallium, cobalt-chromium, vitreous carbon, aluminium oxide ceramics, or nicel-chromium-vanadium alloys. Even with the  favoured titanium metal, the implant surface maybe rough or  smooth, and may have an additional hydroxyapatite or titanium-spray coating. There appears to be a lac of consensus among researchers and clinicians regarding the best design for an implant. The  main area of dispute focuses on how an implant gains its support from the surrounding bone.  screw thread around the implant surface aids loading of the surrounding bone in compression, whereas a smooth cylindrical design increases implant support when shear forces are exerted on the bone. 5oth these varieties show a more uniform stress distribution under loading when compared to other designs.

Osseo-integrated implants and orthodontics #n malocclusions requiring a high level of anchorage an chorage control, osseo-integrated implants can be used on a temporary basis to minimize loss of anchorage. 1oberts, used conventional, two-stage titanium implants in the retromolar region, to help reinforce anchorage whilst successfully closing first molar  extraction sites in the mandible. fter completion of the orthodontic  treatment, the implants were removed using a trephine and histologically analysed. They found a high level of osseo-integration had been  maintained, despite the orthodontic loading. #n another study,  Turley et al . used tantalum marers and bone labelling dyes in dogs to illustrate the stability of two-stage implants in  cases of orthodontic or orthopaedic traction. This wor also showed that one-stage implants were less successful in this role. 

 

#mplant-based anchorage can be of particular benefit in treating certain aspects of malocclusions, for example"  • • • •

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1etracting and realigning anterior teeth with no posterior support.   6losing edentulous spaces in first molar extraction sites.  6entre-line correction when missing posterior teeth.     1e-establishing proper transverse and antero-posterior position position of isolated molar abutments.  #ntruding?extruding teeth.  >rotraction or retraction of one arch.     Stabilization of teeth with reduced bone support.  !rthopaedic traction. 

 Design of orthodontic implants !ne of the obvious disadvantages of two-stage implants for orthodontic anchorage is the need for a long healing period of 739 months, which adds significantly to the treatment   time. The bone height required for traditional endosseous implants may also restrict the locations available for implant placement.  s a result of these problems, implants have  been designed specifically for orthodontic purposes. #deally, an implant used to enhance en hance   

orthodontic anchorage should   biocompatible, inexpensive, easily inserted and removed under local anaesthesia, and bebe small enough to locate in multiple sites in the mouth. #t   should also osseo-integrate in a few days, and would be stable to orthodontic  loading in all planes of space.   5loc and 0offman addressed the issue of bone height by developing a disc-lie structure called an Bonplant , which is designed to be placed under local anaesthetic. This hydroxyapatite-coated disc is $C mm in diameter by b y ' mm  thic, and is placed subperiosteally on the posterior aspect of the hard palate, using a Btunnelling surgical    procedure. The latter minimizes the potential for infection to occur around the onplant. fter a $C-wee healing period, the onplant is surgically exposed and a ball-shaped abutment <which replaces the cover screw= is attached. This is subsequently connected to orthodontic bands on the upper molar teeth by a transpalatal arch. This mechanism has  been shown  to resist greater  than 'CC g of continuous orthodontic force, which  is comparable to the force required for conventional space closure of orthodontic extraction sites. fter correction of the malocclusion, the  onplant is removed using an osteotome,  but the authors do not elaborate on any complications associated with this removal   technique. lthough the onplant requires less bone depth compared to conventional endosseous implants and the period of consolidation co nsolidation is approximately half as long, the surgical procedure is complex.  The secondary surgical procedure to uncover the integrated onplant involves a large area of soft tissue being re-exposed, which  is quite traumatic to the patient. #n addition, the use of an  osteotome to remove the onplant under   local anaesthetic may be disconcerting for the patient. Mini'cre* i#$&ant : the Aarh(' '+'te# 6osta and colleagues colleagues described a miniscrew miniscrew with a head that imitated imitated a bracet, thereby facilitating wire placement between the head of the screw and a tooth, the tooth being

 

us used ed as ancho anchora rage ge.t .the he init initia iall desig design n ha had d a l lle len n wr wren ench ch ty type pe ho hole le in th thee he head ad fo forr  placement. This design was later replaced by a miniscrew with a bracet lie head. #t is available in either $.8mm or & mm diameter.the length of both the threaded screw and the transmucosal collar variesto accommodate the thicness of the bone and mucosa in different locations in the oral cavity. The latest generation are self drilling This system is indicated in two groups" adult patients with insufficient teeth for the establ est ablish ishmen mentt of convent convention ional al anchor anchorage age and any patien patientt where where reacti reactive ve forces forces are anticipated to cause adverse effects. THE SPIDER SCRE, ANCHORAGE SYSTEM This Th is is a self self ta tappi pping ng,, comme commerc rcia iall lly y pure pure tita titani nium um mi mini nisc scre rew. w. The The sc scre rew w ca can n be immediately loaded with forces in the range of 8C to 'CCg. vailable in either $.8mm or &.Cmm diameter. The $.8mm comes in lengths of 9, :, or $Cmm. The &.Cmm comes as A, %, or $$mm lengths.The placement of screw requires sufficient bone depth of atleast &.8mm to protect the anatomic structures. INDICATIONS:

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SELECTION O! MINI IMPLANT SI-E AND LOCATION

The diameter of the mini screw will depend on the site and space ava available. ilable. #n the maxilla, a narrower implant can be selected if it is to be placed between the roots. #f stability depends on insertion in to trabecular bone, a longer screw is needed, but if cortical bone will provide enough stability, a shorter screw can be chosen. >ossible insertion sites include, in the maxilla" the area below the nasal spine, the palate, the alveolar process, the retro molar area,and the symphysis. n intra oral radiograph is required to determine the correct location. Dhenever possible, the mini implant should be inserted through attached gingival. #f this is impossible, the screw can be buried beneath b eneath the mucosa so that only a wire, a coil spring or a ligature passes through the mucosa. #n the maxilla, the insretion should be at an oblique angle, in an apical direction/ in the mandible, the screw should be inserted as parallel to the roots as possible.

 

PLACEMENT PROCEDURE

 small amount of local anesthetic is sufficient for surgical procedure. Try not to achieve  profound anesthesia of teeth. The teeth will be affected only if the bone drill approaches their roots, in which case the drill can be redirected away. Dhen anesthetizing the palatal mucosa, the needle can probe and measure the mucosal thicness and help determine the screw length necessary for anchorage. The implant sites should be mared with brass wires before drilling. d rilling. 2axillary micro C implant sites need a 'C-7C angulations to the long axes of the teeth, either buccally or lingually , to increase the surface contact between the microscrew and the bone. The thicer mandibular cortical bone requires $C-&CCof angulation. fter (  is applied, wash the implant area with .C& chlorhexidine. 2elsen et al. recommend , that even when sself- drilling screws ae used, pilot drilling may be required where the cortex is thicer than &mm, as in the retro molar area or the symhysis, because dense bone can bend the fine tip of the screw. The pilot drill should be .&mm - .'mm thinner than the screw and should be inserted to a depth of no more than &-'mm. #f a manual screwdriver is used for insertion, it is immediately evident when a root has been contacted. (ow speed drill reduces the tactile sensation. SURGICAL GUIDE !OR OPTIMAL POSITIONING O! MINI IMPLANTS !ptimal positioning has always been critical to the effectiveness of dental implants.  careful clinical and radiographic assessment before omplant placement is necessary. nother critical factor in orthodontic mini implant placement is the angle of insertion. 1ecommended angles of the implant to the long axes of teeth have ranged from $C-&C C in the mandible and from 'C-7C C in the maxilla.

CLINICAL APPLICATIONS O! THE MINISCRE, IMPLANT

$. 6losure 6losure of extraction extraction spaces" (oss of posterior posterior anchorage anchorage during extractio extraction n space closure can exacerbate the curve of spee and deepen the bite. 2iniscrew provide reliable seletal anchorage for anterior retraction in either arch, whether a single tooth at a time or en masse. 2axillary miniscrews are placed between the roots of the first and second  premolars, where the large interredicular space typically allows easy insertion insertion without root interference. The screw heads can be situated at or above the mucogingival line, depending on the desired line of action. #f both intrusive and distallising forces are needed, the miniscrew should be positioned above the muco gingival line. #f the primary movement is distalliasing , miniscrew placd at the mucogingival line. The higher the screw is placed in the maxilla, the more perpendicular to the bone it must be to avoid damage to the maxillary sinus. #n mandibular arch, minisrews can be useful in patients with maximum anchorage needs , such as bialveolar protrusion and class### cases.

 

&. Symmetric Symmetrical al incisor intrusio intrusion n" in patients patients with moderate moderate to severe deep bites requiring pure intrusion of the anterior teeth to occlusal plane, miniscrews can be used. To providde anchorage during incisor intrusion, miniscrews placed between the upper lateral incisors and canines. The insertion should be done after leveling and aligning , so that maximum amount of interradicular space will be available. To avoid tipping og incisors buccally arch wire should be cinched bac. '. 6orrection 6orrection of a canted canted occlusal occlusal plane" miniscrew miniscrewss provide provide seletal seletal anchorage anchorage for intrusion of the appropriate teeth on the canted c anted side. The screws can be inserted  between the upper lateral incisors and canines, the upper canines and premolars, or the lower lateral incisors and canines. To avoid av oid interference with the teeth to be intruded, it is important to center the miniscrew between their roots. 7. lignment lignment of dental dental midlines midlines" a screw can be placed either either lingually lingually or bucally bucally so that the head stands out at the crown margins. Thus, the line of force is directed more occlusally , with an enhanced horizontal vector. 8. Extrus Extrusion ion of imp impact acted ed canines canines" 2inisc 2iniscrew rewss can be used used instead instead when heavy heavy forces are required to bring an impacted canine in to occlusion, without relying on the rest of teeth for anchorage. 9. 2olar 2olar intrus intrusion ion" minis miniscre crews ws are reliab reliable le source source of anchor anchorage age for intrusio intrusion n of  posterior teeth. #t is difficult to place p lace them precisely in narrow space between the roots of first and second molars without interfering with the roots. #n open bite cases requiring bilateral intrusion of the posterior segments, miniscrews are not ideal solution. A. 2olar 2olar distal distalisa isatio tion n" molar molar distal distalisa isati tion on applian appliances ces have become become increa increasin singly gly  popular for the correction of class ## malocclusion. The ideal site for seletal anchorage is palate. The 2S F distal Get is used. :. 2olar mesial mesialisat isation ion " molars molars are often often moved mesially mesially in orthodon orthodontic tic treatmen treatmentt to close extraction spaces or edentulous spaces.  miniscrew placed mesial to the space, at a height that will produce a force vector approximating the center of resistance of the molar, can be variable source of anchorage. %. #ntermaxil #ntermaxillary lary anchorage anchorage " 2iniscr 2iniscrews ews are a convenie convenient nt source source of anchorage anchorage in  both extraction and non extraction therapy when inter maxillary forces are applied with class ## elastics or anterior repositioning appliances.undesirable effects of these mechanics are bite opening and excessive protrusion and proclination of lower incisors. !ne possible solution is to place a miniscrew between the roots of the lower first and second molars or, second premolar and first molar, the latter is  p7referred because the screw can be inserted perpendicular and inter radicular space is wider. #n class ###, when the maxillary arch needs to be advanced, miniscrews can be  placed between the roots of the lower canines and first premolars for elastic attachment. $C. Hpper third molar alignment alignment" Hpper third third molar can be uprighted uprighted with a fixed secti sec tional onal wire, wire, utiliz utilizing ing a palata palatall minisc miniscrew rew for selet seletal al anchora anchorage ge to limit limit unwanted extrusion of the molar.

 

"one . i#$&ant interaction •

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Endosseous implantation in to cortical bone elicits a unique sequence of modeling and remodel remodeling ing events events that that are critic critical al to healin healing, g, ada adapta ptatio tion, n, and long long ter term m maintenance of the bone implant interface. 6allus formed at the endosteal and periosteal surfaces is the first vital bone to contact the implant. #nitial healing response is driven by release of local chemical factors such as >)4;, T4;-I and >4s.   1emo 1e model delin ing g of bonebone- im impl plant ant inte interf rface ace is of im impo port rtan ance ce be beca caus usee it is th thee mechanism for forming a vital interface between the implant and host bone.

Peri i#$&ant %one re'$on'e to O+onarte et a& /A0O a(g('t 122345 •

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orthodontic

&oading

Smaller amounts and less variability in crestal bone loss were seen in porous surface implants compared with machine threaded implants in both control and orthodontically loaded subGects. !rthodontic loading does not seem to affect the amount of direct bone-to-implant contact !sseo integrated implants. #mplantwith surface design appears to be an important determinant of peri implant  bone remodeling with dental implants used as orthodontic anchorage units. Sint Si nter ered ed , porous porous su surf rfac acee im impl plant antss sh show ow more more fa favo vora rabl blee pa patt tter erns ns of bone bone remodeling under orthodontic loading compared with machine threaded implants, suggesting that shorter implant lengths still maintain !sseo integration.

Dri&& free ' Dri&& t+$e i#$&ant'  Drill free advantages: 1educe operative time (ower morbidity (ess invasive ); had more bone 3to-implant contact and a larger bone area than ) type. ); had increased level of bone bo ne remodeling and !sseo integration. ;or easy removal, low torque is needed which is proportional to the square of screw radius. 1emoval torque is directly proportional to screw radius and bone contact area, which is proportional to screw radius under same bone contact ratio. Dhen Dhe n screw screw radius radius reduces reduces to one-thi one-third? rd? one-fo one-fourt urth, h, the removal removal torque torque is decreased by one-ninth ? one-sixteenth. s bone density increases, the resistance created by the stress surrounding the screw  becomes important in removal than in insertion of the screw. t removal, the stress is concentrated in nec, which may lead to fracture. • • • •

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!ORCE LOADING HO, LONG SHOULD ,E ,AIT "E!ORE LOADING6  #f the implants are  planned for future prosthetic abutments, a standard healing protocol should be followed. )irect orthodontic forces generate less stress on implants due to limited force impose <'CCgm=. Dith dense bone and satisfactory stability, immediate loading might be feasible. Threaded implants provide superior mechanical interloc as compared with cylindrical designs. Thus, waiting time should be longer for non threaded implants.

Implant vs. Screw Loading Protocols O%7ecti8e: This systematic review presents the loading protocols applied when using implants and?or screws in orthodontic treatments. Materia&' and Method': 6linical trials which assessed the use of implants and?or screws for orthodontic anchorage ancho rage and studies involving treatment on syndromic patients, surgery, other simultaneous treatments, or appliances <ie mini-plates= were considered. Electronic databases <2edline, 2edline #n>rocess J !ther on-#ndexed 6itations, (ilacs, >ubmed, Embase, Deb of Science, and ll Evidence 5ased 2edicine 1eviews= were searched with the help of a senior 0ealth

Sciences librarian. bstracts which appeared to fulfill the selection criteria were selected  by consensus. The original articles were then retrieved and evaluated with a methodological checlist. 1eferences were also hand searched for possible missing articles. Re'(&t': Eleven articles fulfilled the selection criteria established. ;ive studies involved the use of implants while six involved the use of screws for orthodontic  purposes. n individual methodological analysis for each article was made. Conc&('ion':  (oading protocols for implants involve a minimum waiting period of & months before applying orthodontic forces while loading protocols for screws involve immediate loading or a waiting period of & wees to apply forces. Success rates for implants were on average higher than for screws.

Dhen reviewing the implant studies, all presented a waiting period before loading for orthodontic reasons. These waiting periods varied from & months & to a maximum of $& months,& pre Screws present some advantages when compared with implants. ;or example, they do not present maGor anatomical limitations for insertion, no surgery is necessary, and the cost is low.'38 lso, there are no symptoms after insertion, ' no laboratory wor is necessary, they are easy to remove, 8 and they only require a short $C,$A $A 7,8 waiting period before loading, 7,8  if any. ',',A,A,$C,  This last advantage reduces the treatment  period and, thus, increases patient acceptability.$C The short waiting period for healing and osseointegration after screw insertion is because of mechanical retention that is initially obtained. This gives the screws a sufficient ',8  primary stability to resist orthodontic orthodontic loading forces,',8  ranging between 'C and &8C g % used in different orthodontic movements.  evertheless, this short waiting period is sufficient forahealing but not for osseointegration, is an important factor inthe maintaining rigid anchorage unit. 0istologically,which it has been demonstrated that

 

 premature load generates the formation of fibrous tissue between the bone and the screw. This layer of tissue gives the mechanical retention for the screw to not displace in the direction of the applied force.8 #n some cases, this layer of tissue can become granulation tissue because of the short time given for the formation of a correct osseointegration.$: (iou et al8 demonstrated that the screws are clinically stable but not absolutely stationary when forces are loaded on them, which, in the case of implants, would be  because of the correct osseointegration. lthough there is some displacement by the screws, they have enough stability to complete the treatment. These screws mostly move toward the direction of the applied force, ranging from K$ to $.8 mm displacement. ;or this reason, it is recommended that they should be placed & mm away from any vital anatomical structure <roots, nerves=. 6oncerning the forces applied to implants or screws, these should be proportional to the amount of osseointegration, which at the same time depends on the surface con contact tact %,$% $% %,  between material and osseous tissue.  ;actors that are involved in this increase in surface are length, diameter, and shape of the appliance.% ccording to ;avero et al,%  there is an inverse relationship between length and an d diameter where if the length decreases, the diameter should increase. #n this regard, studies on screws establish that ',7 ',7 ' the length of the screws have no relationship with their stability,  whereas the diameter does. .

The following conclusions should be considered with caution because only a secondary level of evidence was found. •

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(oading protocols for implants involve a waiting period of o f a minimum of & months before applying orthodontic forces. (oading protocols for screws involve immediate loading or a waiting period of & wees to apply orthodontic forces. The success rates for implants were, on average, higher h igher than for screws. IMPLANT MAINTENANCE

fter surgery, the surrounding soft tissues must be maintained to ensure longevity of implant. >laque accumulation near the gingival margin can cause perimucositis. >rolonged inflammation leads to breadown of bone bo ne around implants and periimplantitis. Therefore, patient is instructed to follow daily plaque control at home and have periodic professional care. COMMON PRO"LEMS ASSOCIATED ,ITH MINI IMPLANTS • • •

Screw related problems !perator related problems  patient related problems

 

Scre related problems: $.  screw screw can fractur fracturee if it is too narrow narrow or the nec nec area is not strong strong enough t owithstand the stress stress of removal. The solution solution is to choose a conical screw with a solid nec and a diameter appropriate to the quality of bone. &. #nfection #nfection can can develop develop around the the screw screw if the the transmucos transmucosal al portion portion is not entirely smooth. Operator related problems: $. application application of excessive excessive pressure pressure during during inserti insertion on of a self drilli drilling ng screw can can fracture the tip of the screw. &. over tighteni tightening ng can cause it it to loosen. loosen. #t is crucial crucial to to stop turning turning the the screw as as soon as the smooth part of the nec has reached periosteum. '. with a bracet bracet lie lie screw head head , the ligature ligature should should be placed placed on top of the the screw screw in the slot perpendicular to the wire. 7. it is import important ant not to wiggle wiggle the screw screw driver driver when when removing removing it from screw screw head. head.  !atient related problems: $. the prognosis prognosis for for primary primary stabili stability ty of a mini mini implant implant is poor in cases where where the the cortex is thinner than .8mm and the density of trabecular bone is low. &. #n patients patients with with thic mucosa, mucosa, the the distance distance between between the point point of force force application application and the center of resistance of the screw will be greater than usual, thus generating a large moment when a force is applied. '. loosening loosening can occur occur , even after after primary primary stabilit stability y has been achieved achieved,, if a screw is is inserted in an area with considerable bone remodeling because of either resorption of a deciduous tooth or post p ost extraction healing. 7. mini implan implants ts are contra contra indicated indicated in patients patients with with systemi systemicc alteration alteration in the bone bone metabolism due to disease, medication , or heavy smoing.  

I#$&ant' for orthodontic anchorage4 Meta9ana&+'i'4 <La%ana('aite ", 0ana('a' G, a'i&ia('a' A, Haffar N.=   The purpose of this article was to review and an d update current data of the use of implants for orthodontic anchorage.  meta-analysis of selected literature was carried out and a total of 7$8 articles were identified in this process. 0aving reviewed the articles or their abstracts?summaries the data were evaluated and the articles were categorized according to the Gournal and the year of publication, the type of the article and the type of the implant. The interest in the possibilities of the implant usage for orthodontic anchorage an chorage is noticeably increasing and today it has reached the pea. #n order to facilitate the understanding of the wide range of implants, we suggested the classification of the implants for orthodontic anchorage according to the shape and size, the implant bone contact and the application ap plication of the implant. De systemized the information about types of implants and their advantages in respect of o f traditional orthodontic treatment.

 

I#$&ant' in o'teogenic di'traction •

>ilot studies on the maxilla and mandible, undertaen by Heda et al have illustrated the use of !sseo-integrated implants to transfer continuous distraction forces through the full width of the distraction site. This has been successfully completed in mandibular lengthening, maxillary advancement, and alveolar ridge augmentation but requires further research prior to becoming an established technique

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MICROSCRE, IMPLANT ANCHORAGE SLIDING MECHANICS  Step-by-step procedure procedure •

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 "A#I$$A%& A%'H: >lacement of microscrew implant implant into the alveolar bone between ## premolar and # molar on both sides. 5onding of C.C&& >E and transpalatal bar for maintaining arch form. >artial canine retraction/ a canine tied bac to the microscrew implant. En masse retraction of 9 anterior teeth via C.C$9LC.C&& C.C$ 9LC.C&& archwire hoos / iTi closing coil spring conncts the anterior hoos to the microscrew implant and applies $8Cg of force on each side. ;inishing/ occlusal settling with vertical elastics.  "A(DI)*$  "A(DI )*$A% A% A%'H: A%' H: >lacement of microscrew implant between the first and second molars on both sides. >artial canine retraction/ the canine is tied bac to the second premolar. En masse retraction of 9 anterior teeth via C.C$%LC.C&8 C.C$ %LC.C&8 inch archwire. pplication of an intrusive force to upright and intrude the mandibular molars by ligating an elastic thread from implant to mandibular archwire. ;inishing

6ontrolling the mode of anterior tooth retraction are" •

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!cclusogingival position of the implant, the height of the anterior hoos, and the amount of torquing curve given on the arch wire. #mplant placed low position -7mm gingival to arch wire distalizing force in non extraction cases >osition at :-$Cmm gingival to arch wire retraction of anteriors in extraction cases

Characteri'tic' Characteri'ti c' of MIA '&iding #echanic' •

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llows bodily retraction of 9 anteriors, while utilizing the force near the center of resistance. #nduce early changes of profile. Hprighting and intrusion of mandibular molars induce autorotation of mandible. 1educes treatment time.

 

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MINI"ONE PLATES: THE S;ELETAL ANCHORAGE SYSTEM The SS comprises of bone plates and fixation screws. They are made o off commercially  pure titanium that is biocompatible and suitable for osseointegration. osseointegration. The anchor plate consists of ' components 3 the head, the arm and the body. The head component is exposed intra orally and positioned outside of the dentition so that it does not interfere with tooth movement. The head has ' continuous hoos for attachment of orthodontic forces. Two different types of head based on directionof hoos. The arm is transmucosal and in ' lengths- short <$C.8mm=, medium<$'.8mm=, long<$9.8mm=. The body is positioned sub periosteally and in ' configurations- T plate, M- plate and #  plate. 2axillary sites " zygomatic buttress b uttress and piriform rim 2andible" lateral cortex in most locations except adGacent adGacen t to mental foramen.  M plate maxilla at zygomatic zygomatic nutress to intrude and distalise distalise upper molars # plate in piriform opening for intrusion of upper anteriors or protraction p rotraction of upper molars. T or ( plate placed in body of mandible to intrude , protract or distalise lower molars. t anterior border of ascending ramus to extrude impacted molars.

 !lacement procedure " procedure " under (  with #@ sedation. #nitially a mucoperiosteal incision is  performed in the buccal vestibule.  vertical incision is usually made in maxilla and horizontal incision in mandible.flap elevated to expose the bony cortex. 5ased on the distance between the surgical site and the dentition on x ray , the appropriate shape and length of anchor plate is selected.plate contoured to final position and placed. The a pilot hole is drilled , and a self tapping mono screw is placed. The remaining screws are inserted to firmly attached the anchor plate to the bone surface. (ast surgical site closed with resorabable sutures. Significant advantage it allows the acheievement of predictable three dimensional molar movements. Timing of orthodontic treatment" treatment" orthodontic force is applied about ' wees after implantation procedure, but before the osseointegration o sseointegration of the titanium screws are implants. #mmediately after orthodontic treatment , all anchor plates are removed. dvantages" $. 2ade 2ade of pure pure titan titanium ium , its its safe safe and and stabl stable. e. &. )o not distur disturb b any ind ind of tooth tooth system system as placed placed outside outside dentit dentition. ion. '. Easy Easy cont control rol of occ occlus lusal al plan plane. e. 7. pa pati tien entt compl complia ianc ncee not need needed ed

CONCLUSION The concept of temporary anchorage device is a relatively new application of more established clinical methodologies. lthough the clinician can loo to the literature for many answers, much is unnown and will only be answered by well designed  prospective basic science and clinical trials. The future development of temporary anchorage devices for orthodontic anchorage will establish a more complete understanding of biology and biomechanics associated with both !sseo integrated and non integrated devices.