Micro Implant Anchorage in Orthodontics / orthodontic courses by Indian dental academy

MICRO IMPLANT ANCHORAGE

IN

ORTHODONTICS INDIAN DENTAL ACADEMY

Leader in continuing dental education www.indiandentalacademy.com

www.indiandentalacademy.com

INTRODUCTIONOral implantology has recently become the object of growing attention.

Successful long term Osseo integration,has greatly increased the use of dental implants over the last 3 decades.

Other than replacing missing teeth,implants can also be used to enhance orthodontic treatment -as a source of absolute anchorage, -for orthopedic anchorage, -as abutments for restorations, -in osteogenic distraction.


During active treatment,orthodontic anchorage aims to limit the extent of detrimental,unwanted tooth movement.

The ability of Osseo integrated implants to remain stable under occlusal loading has led orthodontists to use them as anchorage units without patient compliance


History The earliest implantation in the sense of reimplantation,Date back to pre-Christian times .

In 18th and 19th centuries artificial materials were used as implant materials but were proved to be failures andwere abandoned.

Endosseous implants became a major influence within the oral implant Surgery due to the work of Branemark whoachieved constant Long term success rates with oral endosseous implants.

In the early 1930s the introduction of stainless metals and the development of a cobalt-chromium-molybdenum alloy (vitallium) gave new impulses to implant surgery.


Dahl(1945),first published the use of subperiosteal vitallium implants to effect tooth movements in dogs

Linkow (1966),described endosseous blade implants with perforations for orthodontic anchorage.

Kawahara etal(1975), developed ,Bioglass-coated ceramic implants for orthodontic anchorage

Various bioactive ceramics such as glass ceramics(Bromer etal 1977,Hench etal 1973),tricalcium phosphate ceramics (Luhr and Riess,1984) and hydroxy appetite ceramics(Hajek and Newesely,1963; Jarcho etal, 1977)


Branemark (1969,1977) the mentor of modern implant surgery ,described the high compatibility and strong anchorage of titanium in human tissue and coined the term “Osseointegration”

Creekmore (1983) reported the possibility of skeletal anchorage in orthodontics

Higuchi and James (1991) used titanium fixturesFor intraoral anchorage to facilitate orthodontic tooth movement.

Costa etal (1998) used miniscrews for orthodontic anchorage

Ume mori etal (1999) used SAS for open bite correction. www.indiandentalacademy.com

CLASSIFICATION Based on their position: -subperiosteal, -transosseous, -endosseousBased on material of construction: -titanium,ideal material -gold alloys, -vitallium, -cobalt-chromium, -vitreous carbon, -aluminium oxide ceramics


Based on their design: -screw type -cylindrical type -blade type -onplant


Indications for implant therapy.

motivated,cooperative,good oral hygiene

growth of alveolar process should be completed


Contraindications for implant therapyAbsolute contraindications: -severe systemic disorders; osteoporosis, -psychiatric disease,e.g.pyschoses,dysmorphobia. -alcoholics,drug abusersRelative contraindications: -insufficient volume of bone, -poor bone quality, -pts undergoing radiation treatment, -insulin-dependent diabetes, -heavy smokers


TITANIUM AS AN IDEAL IMPLANT MATERIAL

Titanium is a reactive metal -forms an oxide layer on contact with air, water or any electrolyte,which protects it from chemical attack including aggressive body fluids

Titanium is inert in tissue – i.e.,no ions are released which are reactive with the body tissues


Titanium possesses good mechanical properties -tensile strength=st.steel -tough and malleable,makes it insensitive toshock loading and will yield on heavy loads -corrosion resistant

Titanium is a bioactive material -bone grows into rough surface of the metal and bonds with metal leading to osseointegration


Uses of implant-based anchorage

• Retracting and realigning anterior teeth with no Posterior support • Closing edentulous spaces in first molar extraction sites

• Mid-line correction when missing posterior teeth,

• Intruding/extruding teeth,

• Protraction or retraction of one arch

• Stabilization of teeth with reduced bone support• Orthopaedic traction


Measurement of alveolar bone heightwww.indiandentalacademy.com

Tissue response following implant placement

Stage I;Woven callus (0-2wks) -bridging callus forms within a few millimeters from the margin of implantation site, -stability of the approximating segments is important for efficient bridging callus formation

Stage II;Lamellar compaction (2-6wks) -is the period of lamellar compaction, -callus matures and achieves sufficient strength for loading.


Stage III;Interface healing (2-6wks) -begins at the same time callus is completing lamellar compaction, -callus starts to resorb and remodeling of devitalized interface begins.

Stage IV;Maturation (6-18wks) -bone matures by a series of modeling and remodeling process -callus completes resorption(modeling)


Long term maintenance

Repetitive loading results in microscopic cracks Which if accumulates lead to structural failure.

Osteoclasts resorbs oldest and most weakenedBone which maintains structural integrity.

This remodeling of the interface and supporting bone helps in long term maintenance of rigid osseous fixation.


MINI-IMPLANTS

Conventional-3.5-5.5mm dia, 11-21mm length

Small in size;1.2mm dia,6mm length


mini-implant for cuspid retraction

For molar intrusion


For molar distalization

For anterior intrusion


Steps in placement of mini implant

(Osseointegrated)1.Reflection of mucoperiosteal Flap and denuding of bone

2.Pilot drill used to enter same Distance as length of mini-implant


3.Mini implant inserted

4.Implant site sutured


5.Gingival tissue exposed Over head of mini implant

6.Soft tissue surrounding headOf mini-implant


7.titanium bone plate attached to head of mini-implant


NON OSSEOINTEGRATED MINI IMPLANTS: (Spider screw)

Advantages:

small in size,

inexpensive,

simple to place and remove,

immediately loadable,

well tolerated by patients,www.indiandentalacademy.com

spider screw

-is a self-tapping titanium mini screw -available in three lengths-7mm,9mm,& 11mm. -screw head has an internal slot of .021”x.025” external slot of.021”x.025” round vertical slot of .025”


Available in three forms

Regular-thicker head & intermediate length collar

Low profile-thin head & long collar

Low profile flat-thin head & shorter collar


Site for placement:

should have enough bone depth to accommodate the screw & 2-3mm of bone width to protect adjacent dental roots and anatomical structures typical insertion areas -maxillary tuberosity -retromolar areas -edentulous ridges -interradicular septi -palate -anterior alveolar process


Determination of screw placement site:

Acrylic surgical index


SURGICAL PROCEDURE

Osseous site preparation with 1.5mm pilot drill

Spider screw insertion with low speed

Contra-angle(30rpm)


Screw removal Immediately after removal

Seven days laterwww.indiandentalacademy.com

Case Report

Extrusion of maxillary molars-pre Rx


Intrusion of premolar & molars using coil springs & elastics to spider screw


Post-Rx –after intrusion of molars


Treatment planning phase • problem list & patient desires

• initial evaluation

1. chief complaint 2. medical/dental history review 3. intra/extra oral examination 4. evaluation of existing prosthesis 5. diagnostic impressions/articulated

casts 6. radiographs (panoramic and

periapical, CT scan or tomography – as indicated)

7. photographs www.indiandentalacademy.com

Problem list & treatment

considerations


TEETH – NUMBER & EXISTING CONDITION INCLUDING:

prognosis of remaining teethsize, shape & diameter of existing dentitiontooth & root angulations & proximity mesiodistal width of edentulous space**Need: minimum of 6-7mm between teeth to facilitate implant placement (based on 3mm fixture)> 1.5mm between implant and natural teeth 7mm from center of implant – to center of implant for edentulous area**If more than 10mm mesiodistal space – then single tooth implant not recommended


bone support – quality & quantity (Lekholm & Zarb classification)

quality: best is thick compact cortical bone w/ core of dense trabecular cancellous bonebest region is mandibular symphysis; poorest in posterior regionsquantity: required for implant placement: 6mm buccal-lingual width w/ sufficient tissue volume8mm interradicular bone width 10mm alveolar bone above inferior alveolar (IAN) canal or below maxillary sinus**If inadequate bone support, may need ridge or site augmentation:ramus or chin graft (autograft)DFDBA (allograft)Bio-Oss(xenograft)**implants should be placed at a minimum of 2mm from the inferior alveolar (IAN) canal orbelow the maxillary sinus



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Micro Implant Anchorage in Orthodontics / orthodontic courses by Indian dental academy

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