3. • No steel/elastomeric ligatures
• Frictional force of ligatures ( O configuration)= 50 g
• Reduced friction- especially passive design
• Less force required for tooth movement
• More physiological in terms of PDL vascular supply
• More alveolar bone generation, greater expansion, less proclination of
anterior teeth, less need for extractions
Kapur et al:
• Friction per bracket with Ni-Ti archwires-41g under conventional ligation and
15g with Damon system
• For SS wires: 61g (conventional); 3.6g (self ligating)
BIOMECHANICAL APPROACH
Self Ligating Bracket System
4. • Despite low friction, do not perform faster alignment/ space closure
• They are narrower than conventional brackets- effect of binding due to
tipping is greater- increased resistance
• Short chair side time and less incisor proclination (1.5 degree)
Self Ligating Brackets- Current Evidence
BIOMECHANICAL APPROACH
1.Chen SS et al. Systemic review of self ligating brackets. Am J Orthod Dentofacial
Orthop.2010;137:726e1:726e18
2. Fleming PS, Johal A. Self ligating brackets in orthodontics. A systemic review. Angle
Orthod.2010;80:575-84
5. Beeson et al & Davidovitch et al:
• Direct current : 7 volts & 15 microamperes
• Anode : pressure side; Cathode: tension side
• Degree of bone formation and resorption at electrically treated pressure &
tension side was higher
• Increase osteoblasts, PDL cells, osteoclasts
Mechanism:
• Direct current generate local response to increase AB turnover
Disadvantages:
• The device and battery providing electric current were bulky
1. Direct Electric Current Stimulation: Evidence
PHYSIOLOGICAL/ MECHANICAL APPROACH
Beesan DC, Jhonston LE, Wisotzky J. Effect of constant currents on orthodontic tooth movement in
cat. J Dent Res 1975;54:251-54
Davidovitch Z et al. Electric currents, bone remodelling and orthodontic tooth movment. Am J
Orthod.1980;77:33-47
6. • Used clinically (2009)
• It utilizes glucose as a fuel and enzymes as catalyst
• Placed on the gingiva near the alveolar bone
• Small size /minimal tissue injury
Disadvantage:
• Short life time
• Poor power density
Enzymatic Micro battery
PHYSIOLOGICAL/ MECHANICAL APPROACH
7. • Electric potentials can be created by applying force to a tooth resulting in
bending of bone and generation of piezoelectric charges
• The charges are created when stress is applied and released
• Vibration could be used to apply and release forces at rapid rate
• AcceleDent vibratory system : High frequency vibration (30Hz) for 20
min/day
Mechanism:
• Stimulate cell proliferation and maturation to allow faster bone remodeling
Endogenous Piezoelectric stimulation
PHYSIOLOGICAL/ MECHANICAL APPROACH
8. • Prospective RCT: 45 patient , Random allocation for use of AcceleDent
appliance
• NiTi coil spring was attached from canine and distally to TSAD
• Distance checked b/w TSAD and distal of canine bracket – every 4 wks
• 39 completed the trial and reported 38% (0.29mm/wk) faster tooth
movement compared to control (0.21mm/wk)
Discussion:
• Lack of blinding & measurement method may affect the outcome
• TSAD can drift under orthodontic loading-1.5mm
• Vibration may results in accelerated drift of TSAD
Conclusion:
Future research needed
Endogenous Piezoelectric stimulation: Evidence
PHYSIOLOGICAL/ MECHANICAL APPROACH
AcceleDent website.http//accledent.com/images/uploads/AcceleDent + increases+the Rate of Orthodontic
tooth movement Results of a RCT Final for Print November 14 2011.pdf Accessed 20 May 2012
9. • Gallium-aluminium-arsenide Irradiation
• Wavelength: 630-860nm energy , energy 4.5-6 J/cm2
• Minimally invasive, simple and safe to apply
Mechanism:
• Increase in ATP at localized site - induce cells to undergo a remodeling process
due to an elevated metabolic activity
• Increase in vascular activity contribute to rapid turnover of bone
Evidence:
• Controversial
• Few studies reported positive result, few no effect and some reported retarded
tooth movement
Low-Level Laser Therapy: Evidence
PHYSIOLOGICAL/ MECHANICAL APPROACH
Youssef M et al. Low energy laser irradiation therapy during orthodontic tooth movement. A preliminary
stud. Lasers Med Sci 2008;23:27-33
Limpanichkul et al. Effects of low laser therapy on rate of orthodontic tooth movement. Orthod Craniofac
Res. 2006;9:38-43
10. • Light with 800-850nm wavelength (just above the visible light spectrum)
penetrates cheeks and soft tissues over AB
• 97% light lost , 3% excite intracellular enzymes and increase cellular activity
in PDL and bone
• Increase blood flow and may enhance tooth movement
Advantage:
• Can be adjusted to apply light to only anterior teeth, whole arch or posterior
teeth
LLL therapy: Photo-biomodulation (Biolux)
PHYSIOLOGICAL/ MECHANICAL APPROACH
11. • Corticosteroids
• PG’s
• Growth Hormone
• Parathyroid hormone
• Active form of Vitamin D
• Relaxin
PHARMACOLOGIC APPROACH
12. Mechanism:
• PGE2 – an important mediator of bone remodeling under mechanical force
(increase cAMP & cGMP)
Yamaseki &Harell et al:
• Experiment on animal model found application of orthodontic force –
increase in PG’s synthesis- stimulate osteoclastic bone resorption
• Injections of PGE1 and PGE2 into gingival tissues near first molar – increase
rate of tooth movement
Prostglandins: Evidence
PHARMACOLOGIC APPROACH
Yamaseki K et al. Prostaglandin as a mediator of bone resoprtion induced by experimental
tooth movement in monkeys. J Dent Res. 1982;61:1444-1446
13. • Following LA, 0.1 ml of a 0.01% PGE1 solution in saline was injected
submucosally at pressure side
• Rate of canine retraction- 1.6 fold increase
Disadvantages:
• Injection were repeated at weakly intervals
• Severe pain after injections
Protaglandins: Clinical trials
PHARMACOLOGIC APPROACH
Speilmann T et al. Acceleration of orthodontically induced tooth movement through the local
application of prostaglandin (PGE1). Schweiz Monatsschr Zahnmed 1989;99:162-165
14. • Insulin family of structurally related hormone
• Produced during pregnancy
Mechanism:
• Increase rate of degradation of extracellular fibrous C.T (stimulate
collagenase)
• Increase bone resorption via increase in TNF and IL-1B secretion
Relaxin
PHARMACOLOGICAL APPROACH
Kristiansson P et al. Does human relaxin-2 affect peripheral blood mononuclear cells to
increase inflammatory mediators in pathological bone loss?.Ann N Y Acad Sci.2005;1041:317-9
Stewart Dr et al. Use of Relaxin in orthodontics. Ann N Y Ascad Sci.2005 1041:379-387
15. • Vitamin D and PTH regulate the amount of calcium and phosphorus levels
• Vitamin D receptors – present on osteoblasts but also in osteoclast precursors
and in active osteoclasts
Collins and Sinclair et al (1988)
• Intraligamentary injections of vitamin D metabolite- increase in the number
of osteoclasts and amount of tooth movement during canine retraction with
light forces
• Stimulatory action of vitamin D on osteoblasts can help stabilize orthodontic
tooth movement.
Vitamin D ( 1,25 Dihydroxycholecalciferol)
PHARMACOLOGICAL APPROACH
16. • Rapid canine retraction through distraction of the PDL
• Rapid canine retraction through distraction of dento-alveolus
• Corticotomy assisted rapid tooth movement
• Corticision/Peizocision
SURGICAL-ASSISTED APPROACH
17. Mechanism:
• Incorporation of a surgical procedure on interseptal bone distal to canine the
time of extraction of first premolar, resistance is reduced
• Rapid canine retraction through distraction (stretching) of PDL
• This approach is based on distraction osteogenesis
• Pressure side: Canine-interseptal bone complex transported distally inside
the socket
• Tension side: PDL distraction leading to osteogenesis
1.Rapid canine retraction via PDL distraction
SURGICAL-ASSISTED APPROACH
18. Rapid canine retraction through distraction of PDL
Procedure
• At the time of extraction of 1st
pm, socket is deepened to the
same depth as canine with a
4mm round carbide bur
• 1mm carbide fissure bur- to
make two vertical grooves,
running from socket bottom to
the alveolar crest, on the MB
and ML corners
• These grooves are joined
obliquely toward the base of
interseptal bone
Liou EJ, Haung CS. Rapid canine retraction through distraction of periodontal ligament. Am J
Orthod Dentofacial Orthop. 1998;114: 372-383
19. Technique:
• Mucoperiosteal flap reflected
• Cortical holes made in alveolar bone from canine to 2nd pm curving apically to
pass 3-5mm from apex
• Connect the holes with tapering fissure
• First premolar is extracted and buccal bone removed
• Large osteotomes are used to mobilize the whole segment
• Distraction : after 3 days of surgery
• Activation of distractor: twice/day in morning and evening
• 0.8mm/day
• Can also be used to bring ankylosed tooth into position
Disadvantage:
• Aggressive and complicated
Rapid canine retraction through dento-alveolar distraction
SURGICAL-ASSISTED APPROACH
Kisniscu RS et al. Dentoalveolar distraction osteogenesis for rapid canine retraction. J Oral
Maxillfac Surgery 2002. 60:389-394
20. • Local injury to the alveolar process reduces resistance to tooth movement and
generate RAP
• First described in 1892 (fitzpatrick Barry)
Indications:
• Resolve crowding and shorten treatment time
• Accelerate canine retraction
• Enhance post-orthodontic stability
• Facilitate eruption of impacted teeth
• Molar intrusion and open bite correction
• Molar distalization
Kole’s technique:
• Flap raised, vertical cuts facially and lingually between and under teeth that
did not penetrate all the way (only cortex)
• Reduce resistance enhances en bloc movement of entire alveolar segment
Corticotomy assisted orthodontic tooth movement
SURGICAL-ASSISTED APPROACH
21. • Accelerated osteogenic orthdontics (AOO) /periodontally accelerated
osteogenic orthodontics
Technique:
• Full thickness flaps are reflected carefully beyond the apices to allow
decortication around apices
• Corticotomy cuts are made in the form of lines and dots
• Small circular depressions were placed in facial surface of bone over
maxillary anterior teeth
• Bio-absorbable graft is placed (demineralized freeze dried bone)
• Tooth movement- should be started after a weak
• Tooth movement should be completed within 3-4 months
Advantages of graft:
• Reduces bone dehiscence/ fenestrations especially when
lower incisors are advanced
• Good healing of alveolar bone
Wilcodontics
SURGICAL-ASSISTED APPROACH
22. Micr0perforation:
• Screws placed in gingiva b/w interproximal AB and removed
• Enough to accelerate RAP
Piezocision:
Minimally invasive flapless procedure combining microincisions, peizoelectric
incisions & selective tunneling that allows for hard and soft tissue grafting
Advantages:
• Minimally discomfort
• Enhanced periodontium (added grafting)
Modified corticotomy
SURGICAL-ASSISTED APPROACH
23. • Minimal surgical intervention
• No flap is raised, No tunneling of hard or soft tissue
graft not given
Indications:
• To resolve anterior crowding
• Anterior open bite
Technique:
• Insert the surgical blade interproximally and parallel to occlusal plane 2-3 mm
apical from the tip of the papilla
• Tap blade with a mallet to a depth of approximately 8mm
• Change the angle of the blade to approximately 45 degrees apically and tap the
blade to incise to a depth of 10mm to 12mm
• The goal is to cut the cancellous bone between the roots to 50% to 75% of the root
length
• Apply orthodontic forces immediately
• See the patient every two weeks; forcibly mobilizing the teeth to induce minor
trauma to extend the effect.
Corticision
SURGICAL-ASSISTED APPROACH
24. • Recent advancement: surgical blade is replaced by piezoelectric puncture
• Punctures rather than incisions penetrate gingiva, cortical bone, cancellous
bone
Advantages:
• Patient friendly
• Less discomfort
• Evidence still needs further investigation
Corticision
SURGICAL-ASSISTED APPROACH
Park YG. Patient friendly orthodontics to accelerate tooth movement. Presented at the 23rd
Annual conference of Taiwan Association of orthodontics. 2011. Taichung, Taiwan.
25. • Autologous platelet rich plasma can simulate the effects
induced by bone surgery
• Platelets contain growth factors PDGF,TGF, EGF’s and other components
that regulate and stimulate wound healing and amplify osteogenesis
Technique:
• 0.9ml of LA injected in the labial and lingual mucosa of anterior teeth
• 0.7ml of PRP injected in labial and lingual attached gingiva from canine to
canine (immediately after bonding)
• Acetaminophen given to control post-injection pain
• The rate of orthodontic alignment was faster than compared to controls
SURGERY SIMULATED APPROACH
Submucosal Injections of PRP
Liou EJ et al. Submucosal injection of platelet rich plasma accelerates orthodontic tooth
movement. Am J Orthod Dentofacial Orthop (in press).
Hinweis der Redaktion
Othodontic treatment is tedious and often takes 2-3 years in adult patients. While the acceleration of orthodontic tooth movement to shorten time is challenging task in orthodontics several efforts have been made.
Self ligating brackets have gained popularity in recent years. The first self ligating bracket the Russell attachment was introduced by Stolzenberg in 1935 to enhance clinical efficiency during ligation time. Subsequently, some other brackets were introduced such as Edgelock, Mobil-Lock, SPEED, Activa.
The claim of reduced friction with self ligating brackets is often cited as primary advantage over conventional bracket system.
Self ligating brackets are divided into two main categories active and passive, Active have spring clip that stores energy to press against the archwire for rotation and torque control. On the other hand the passive have a slide that can be closed which do not encroach on the slot lumen
Self ligating brackets are proposed to have the potential advantages of producing more physiologically harmonious tooth movement by not overpowering the musculature and interrupting the blood supply, Therefore more AB generation, greater expansion, , less proclination of anterior teeth and less need for extractions.
Despite its reduced friction in vitro, several systemic reviews, RCT’s and prospective cohort studies have revealed that self ligating brackets do not accelerate alignment or space closure as previously believed
It is believed that friction does not seem as critical as previously believed and binding may have a greater role in determining tooth movement
Friction: Contact of wire with bracket bottom and walls
Elastic binding: wire contact the corners of the bracket. The greater the angle at which wire contacts the corner of the bracket, the greater the resistance to sliding.
For very early alignment: resistance to sliding is due to combination of friction and binding but almost immediately the frictional component becomes low and binding elastic biniding plays a role in resistance to sliding.
Inelastic binding: When notching of the edge of wire occurs.
The use of minute direct electric current has only been used experimentally in cats. No clinical application has been reported.
The direct electric current used was 7 volts and 15 MA. The anode was placed at the pressure side and cathode was placed at the tension side of the moving teeth.
The clinical application of direct current started when there was a development of biobattery that generates electricity from carbohydrates using enzyme as catalyst.
The disadvantage are short life time and poor power density
It has been suggested that these forces should not be continous because the peizoelectric charges are created when the stress to bone is applied and release. .
Theoritically, vibration could be used to apply and release forces at rapid rate, which could create these stress induced electrical charges.
A prospective RCT examined 45 patients requiring extraction of maxillary first premolar for crowding, The patients were randomly allocated to use either the AcceleDent viratory appliance for 20 min/day
Although the TSAD may be expected to be a stable landmark, TSAD can drift 1.5mm under orthodontic loading which can affect the measure rate of movement.
The most frequently used LLLT for the purpose of potentially accelerating tooth movement is gallium-aluminium-arsenide laser irradiation
According to literature, laser is capable of activating pre-osteoclasts frm PDL to become mature but does not induce bone marrow cells to differentiate into new preostroclasts fast enough
It seems that when pre-osteoclasts in the PDL comes to an end, the affect of laser in process of bone reserption is inexpressive, In this way, laser is ideally recommended only at the initial period of force application
Certain enogenous agents such as inflammaatory mediators like cytokines and PG’s and hormones have been used exogenously in an attempt to accelerate tooth movement . However, only PG’s and relaxin have been tested clinically without any obvious adverse and systemic effects
Prostaglandins are a group of chemical messengers belonging to a family of hormones called eicosonoids. Application of orthodontic force cause increase synthesis of PG’s which in turn stimulate osteoclastic bone turnover
Few clinical studies are available. Although, local injections of PGE2 has demonstrated its clinical effectiveness in accelerating tooth movement however its clinical applications is limited
Relaxin influences many other physiological processes such as collagen turnover, angiogenesis and antifibrosis.
Instead of increasing bone turnover, relaxin increase the rate of degradation of extracellular fibrous connective tissue
Relaxin might be used as an adjuvant to orthodontic therapy, during or after tooth movement, for promotion of stability, for rapid remodeling of gingival tissue during extraction space closure, for orthopedic expansion in non - growing patients, by reducing the tension of the stretched soft tissue envelope, particularly the expanded palatal mucosa, after orthognathic surgery.
Surgical-assosted accelerated tooth movement is currently the most effective technique experimentally and clinically in accelerating tooth movement
This technique is beneficial in treating adult patients in whom treatment duration is the deciding factor towards acceptance of treatment.
The rate of tooth movement in adults is slower than adolescents.
Two basic components are encountered during orthodontic tooth movment are PDL and AB
In the initial stages of tooth movment, Young modulus (stiffness) of PDL is higher in adults leading in delay in early stages of tooth movement. However, Young modulus decreases markedly 4-7 days after application of orthodontic force and does not last through the entire period of orthodontic tooth movement.
Banding and bonding are performed before extraction of first pm. A segment of Ni-Ti archwires is placed on anterior teeth for intial alignment and activation of PDL cells. The period of predistraction phase was 1-2 months.
The surgery is perfomed inside the extraction socket without raising a flap
The length of canine can be obtained from CBCT
The interseptal bone is reduced to 1.0-1.5mm
A custom made distraction appliance is deleivred immediately after extraction and surgical procedures. It is activated at a rate of 0.5mm-1mm/day right after the surgery until canine is distracted into desired position
Transport dentoalveolar segment includes canine, the buccal cortex, underlying spongy bone that underlies canine root
The palatal /lingual cortical plate and bone at the apex of canine remains intact.
Frost found a diret correlation between the severity of bone corticotomy and the intensity of the healing response leadingto accelerated bone turnover at the surgical site.
RAP is a temporary stage of localized soft and hard tissue remodelling that resulted in rebuilding of the injured sitesto normal state through recruitment of osteoclasts and osteoblasts vi intercellular mediator mechanisms
Wilco’s technique (Wilcodontics):
Accelerated osteogenic orthdontics (AOO) /periodontally accelerated osteogenic orthodontics
Selective decortication in form of lines and points is performed over all the teeth to be moved
A resorbable graft is placed
Orthodontic tooth movement started after a weak
Bone remodelling after corticotomy could be accelrated for 2-4 months
This technique combines micro-incisions limited to the buccal gingiva that allow the use of a piezoelectric knife to give osseous cuts to the buccal cortex and initiate the regional acceleratory phenomenon (RAP)[6,7] without involving palatal or lingual cortex. The procedure allows for rapid tooth movement without the downside of an extensive and traumatic surgical approach while maintaining the clinical benefit of a bone or soft-tissue grafting concomitant with atunnel approach.
Conrticision was introduced as a supplemental dentoalveolar surgery in orthodontic therapy to achieve accelerated tooth movement with minimal surgical intervention
This manual manipulation involves the interception of llamellation process of woven bone at the incision site and provides repeated micodamage,
Any procedure involving bone surgery is invasive and aggressive. How can the effects of bone surgery be simulated without surgery?
Local injections of cytokines and hormones has similar effect as that of bone surgery but it is not clinically practical because of its systemic effects and need for frequent injections.
PRP contain 5% RBC’s, 1% WBC’s, and 94% platelets that accelerate soft tissue healing and amplify osteogenesis
Injection of PRP submucosally , the platelets first adhere and aggregate layer by layer on the surface of collagen, the extrinsic and intrinsic pathways of hemostasis intiate to generate thrombin ,platelets clots lay down layer by layer above the periosteum and then the growth factors relase and infiltrate into the periosteum gradually.
