Post on 23-Jan-2018
TOOTH MOVEMENT
Force Application
Elimination
Effects of Force
On bone and teeth
Tension Bone Formation Osteoblasts
Compression Bone Resorption Osteoclasts
Magnitude of Force
> 7-8 grams
Duration of Force
> 4-6 hours
Types of Forces
Continuous
Light sustained forces from NiTi wires and springs
Interrupted
A wire that gets deactivated between appointments
Intermittent
Removable appliances
Effects of Drugs on Orthodontic Tooth
Movement
STEROIDS
NSAIDS
Relaxin
Pregnancy Hormones
Destroyes Collagen
Helps in softening / dilatation of cervix
Increased rate of Orthodontic Tooth Movement
Prostaglandin Inhibitors
NSAIDS
STEROIDS
Slow down tooth movement
Paracetamol
COX 3 Inhibitor
Analgesic
Antipyretic
But not anti-inflammatory
Does not effect the rate of tooth movement
Other drugs
Tricyclic Antidepressants
Antiarrythmic agents
Antimalarials
Phenytoin
Statins
Tetracyclines
Osteoporosis
Estrogen Replacement Therapy
Reduced production of PG and IL-1 and IL-6
Reduced rate of remodeling
ESTROGEN – Uterine Cancers
ESTROGEN + PROGESTERONE – Breast Cancers
Estrogen Receptor Modulator (Anti-cancer?)
Raloxifine
Tamoxifine
Bisphosphonates
BISPHOSPHONATES
Can be
Nitrogenous
Non-nitrogenous
Binds to Hydroxyapatite
Slows down tooth movement
Long half life
In months and years
BISPHOSPHONATES
Can be
Nitrogenous
Non-nitrogenous
Binds to Hydroxyapatite
Slows down tooth movement
Long half life
In months and years
Bisphosphonates
Risks Involved
Osteonecrosis
Slow tooth movement
A challenging task?
Benefits of reduced treatment time
Risks involved
ENHANCING ORTHODONITC TOOTH MOVEMENT
Biomechanical approach
Physiological/mechanical approach
Pharmacological approach
Surgical-assisted approach
Surgery-simulated approach
METHODS OF ENHANCHING TOOTH MOVEMENT
Self-ligating brackets:
Frictional force of ligatures ( O configuration)= 50 g Reduced friction- especially passive design Less force - more physiological 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 (conventional) 15g (self ligating)
For SS wires: 61g (conventional) 3.6g (self ligating)
BIOMECHANICAL APPROACH
Self-ligating brackets:
Despite low friction, do not perform faster alignment/ space
closure
Narrower than conventional brackets – More Tipping – More
Binding
Short chair side time and less incisor proclination (1.5 degree)
1. Chen SS et al. Systemic review of self ligating brackets. Am J Orthod DentofacialOrthop.2010;137:726e1:726e18.
2. Fleming PS, Johal A. Self ligating brackets in orthodontics. A systemic review. AngleOrthod.2010;80:575-84.
BIOMECHANICAL APPROACH
Direct Electric Current Stimulation:
Direct current : 7 volts & 15 microamperes
Anode : Pressure side; Cathode: tension side
More bone formation and resorption at electrically treated sites
Increase osteoblasts, PDL cells, osteoclasts
Mechanism:
Direct current generate local response to increase alveolar bone turnover
Disadvantages:
The device and battery providing electric current are bulky
No clinical application has been reported1. Beesan DC, Jhonston LE, Wisotzky J. Effect of constant currents on orthodontic tooth movement
in cat. J Dent Res 1975;54:251-54
2. Davidovitch Z et al. Electric currents, bone remodelling and orthodontic tooth movment. Am JOrthod.1980;77:33-47
PHYSIOLOGICAL APPROACH
Endogenous Piezoelectric Stimulation
Electric potentials are created by force application
The charges are created when stress is applied and released
Vibration could be used to apply and release forces at rapid rate
Mechanism:
Stimulate cell proliferation and maturation to allow faster bone remodeling
AcceleDent vibratory system:
High frequency vibration (30Hz) for 20 min/day
PHYSIOLOGICAL APPROACH
Endogenous Piezoelectric Stimulation
Prospective RCT: 45 patient , Random allocation for use of AcceleDentappliance
NiTi coil spring was attached from canine and distally to TSAD
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
AcceleDent website.http//accledent.com/images/uploads/AcceleDent + increases+theRate of Orthodontic tooth movement Results of a RCT Final for Print November 142011.pdf Accessed 20 May 2012
PHYSIOLOGICAL APPROACH
Low-Level Laser Therapy (LLLT):
Gallium-Aluminium-Arsenide Irradiation
Wavelength: 630-860 nm; 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:
Few studies reported positive result, few no effect and some reported retarded tooth movement
PHYSIOLOGICAL APPROACH
Youssef M et al. Low energy laser irradiation therapy during orthodontic tooth movement. Apreliminary stud. Lasers Med Sci 2008;23:27-33
Limpanichkul et al. Effects of low laser therapy on rate of orthodontic tooth movement. OrthodCraniofac Res. 2006;9:38-43
Photo-biomodulation (Biolux) Light with 800-850nm wavelength
Penetrates cheeks and soft tissues over alveolar bone
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 according to anchorage requirements
PHYSIOLOGICAL APPROACH
Corticosteroids
PG’s
Growth Hormone
Parathyroid hormone
Active form of Vitamin D
Relaxin
PHARMACOLOGICAL APPROACH
Prostglandins:
Mechanism:
PGE2 – an important mediator of bone remodeling under mechanical force
Increase cAMP and 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
PHARMACOLOGICAL 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
Protaglandins:
Clinical application:
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
PHARMACOLOGICAL 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
Relaxin Insulin family of structurally related hormone
Produced during pregnancy
Mechanism: Increase rate of degradation of collagen (stimulate collagenase)
Increase bone resorption via increase in TNF and IL-1B secretion
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
Vitamin D ( 1,25 Dihydroxycholecalciferol)
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
PHARMACOLOGICAL APPROACH
PDL Distraction
Rapid canine retraction through
distraction of dento-alveolus
Corticotomy assisted rapid tooth
movement
Corticision/Peizocision
SURGICAL-ASSISTED APPROACH
Rapid canine retraction via PDL distraction Mechanism:
Incorporation of a surgical cuts on interseptal bone distal to canine at the time of extraction of first premolar
Rapid canine retraction through distraction (stretching) of PDL
Pressure side: Canine-interseptal bone complex transported distally inside the socket
Tension side: PDL distraction leading to osteogenesis
SURGICAL-ASSISTED APPROACH
PDL DISTRACTION
Procedure At the time of extraction of 1st pm,
socket is deepened to the samedepth as canine with a 4mmround carbide bur
Interseptal bone is reduced to 1.0-1.5mm
A custom made distractionappliance is deliveredimmediately after extraction
Rate of activation:
0.5mm-1mm/day
Liou EJ, Haung CS. Rapid canine retraction through distraction of periodontal ligament. Am J Orthod Dentofacial Orthop. 1998;114: 372-383
Dento-alveolar Distraction
Surgical Technique: Mucoperiosteal flap reflected
Cortical holes made in alveolar bone curving apically to pass 3-5mm from apex
Connect the holes with tapering fissure
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
SURGICAL-ASSISTED APPROACH
Kisniscu RS et al. Dentoalveolar distraction osteogenesis for rapid canine retraction. J Oral MaxillfacSurgery 2002. 60:389-394
RAP
Increased rate of orthodontic tooth movement
Increased remodelling
Transient osteopenia
Regional Acceleratory Phenomenon
Corticotomy Assisted Tooth Movement Local injury to the alveolar process reduces resistance to tooth movement
and generate RAP
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)
SURGICAL-ASSISTED APPROACH
Wilcodontics Accelerated osteogenic orthdontics (AOO)
Periodontally accelerated osteogenic orthodontics (PAOO)
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 are placed in facial surface of bone overmaxillary 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
SURGICAL-ASSISTED APPROACH
Wilcodontics
Advantages of graft:
Reduces bone dehiscence/ fenestrationsespecially when lower incisors areadvanced
Good healing of alveolar bone
SURGICAL-ASSISTED APPROACH
MODIFIED CORTICOTOMIES:
Micro-osteoperforation: Screws placed in gingiva b/w interproximal alveolar bone and removed
Enough to accelerate RAP
Advantages: Minimally discomfort
Enhanced periodontium
SURGICAL-ASSISTED APPROACH
Piezocision:
Minimally invasive flaplessprocedure combining peizoelectricincisions & selective tunneling
Allows for hard and soft tissuegrafting
Indications:
To resolve anterior crowding
Anterior open bite
Advantages: Patient friendly
Less discomfort
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.
Corticision: Aim to cut interradicular bone to 50% to 75% of the root length
Technique: Insert sepcial 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
Apply orthodontic forces immediately
Activation every two weeks
Extra force to induce minor trauma and to extend the effect
SURGICAL-ASSISTED APPROACH
Submucosal Injections of PRP
Autologous Platelet Rich Plasma(PRP) can simulate effects of bonesurgery
PRP contain 5% RBC’s, 1% WBC’s,and 94% platelets
Platelets contain growth factors PDGF,TGF and other components that regulateand stimulate wound healing andamplify osteogenesis
SURGERY SIMULATED APPROACH
Submucosal Injections of PRP
Technique:
0.7ml of PRP injected in labial and lingual attached gingiva fromcanine to canine (immediately after bonding)
Acetaminophen given to control post-injection pain
Rate of orthodontic alignment faster than controls
Liou EJ et al. Submucosal injection of platelet rich plasma accelerates orthodontic tooth movement. Am J Orthod Dentofacial Orthop (in press).
SURGERY SIMULATED APPROACH
In general, all these techniques had draw backs and
uncertainties that made them not commonly used clinically.
However, there has been a rapid increase in the interest levels of product companies to enhance orthodontic tooth movement.
These new approaches have the potential to be the next frontier for orthodontics and its resources.
CONCLUSION
THANK YOU