Orthodontics Flashcards
What are the risks and benefits of orthodontic treatment?
Benefit:
- improved function
- improved aestehtics
Risks:
- reduced dental health
- failre to achieve aims
Name the 7 suggested health benefits of orthodontic treatment?
Reducing caries susceptibility - however caries progression is multifactoral
Reduces Gingivitis and Periodontal disease - other factors can be important
Reducing trauma risk (Correcting Increased overjet) - >6mm overjet 3 x risk
Masticatory Function - overjet/AOB eating difficulties
Speech - malocclusion little impact
Tooth impaction
Psychological well being (Aesthetic impact) - impact on self-esteem
and quality of life
Name the 4 risks of orthodontic treatment?
- Dental caries (Decalcification) :
- ↑poor oral hygiene, cariogenic diet
- Root Resorption (Root shortening)
- Ginigivitis / loss of attachment ↑ patients
with unstable periodontal disease - Soft tissue trauma (Ulcers
What is the purpose of the index of orthodontic treatment need?
developed to help determine likely impact of
malocclusion on dental health and psychological well
being.
Name 3 types of treatment startegies for orthodontic treatment?
Orthodontic treatment only
Orthodontic / Surgical Treatment
Orthodontic / Restorative Treatment
What are the 6 requirements for orthodontic treatment?
- Motivated Patient
- Stable dental health
- Caries free minimum of 12 months
- Healthy periodontium
- Low plaque scores (adequate Oral hygiene)
- Benefits of orthodontic treatment outweigh risks (IOTN)
Name the 4 contraindicators for orthodontic treatment?
- Poor Dental Health (active caries/periodontal health issues)
- Oral Hygiene Issues
- Poor Co-operation / Tolerance issues
- Low treatment need (Risks vs Benefits-IOTN)
Name the 3 types of orthodontic appliances?
- Removable
- Functional
- Fixed
What is the definition of a removable appliance?
An orthodontic appliance that can be removed by the patient
Name the 3 main components of an orthodontic appliance?
- Active Components
- Retentive Components
- Anchorage (Newtons 3rd Law of motion)
- Baseplate/ Bite planes
Name a form of retentive components?
Adams clasps
Name a form of active component?
Palatal finger spring
What is the definition of anchorage?
- Newtons ‘third law of motion’
- For every force applied there is an equal and opposite reactionary
force - Anchorage relates to control of these reactionary forces
Name the 3 planes of space for anchorage?
- A-P
- Transverse
- Vertical
What are the advantages and disadvantages of removable appliances?
Advantages
* Can be removed for cleaning (after meals)
* Cheap (cf fixed appliances)
* Less chair-side time
* Palatal Coverage / Good Anchorage
Disadvantages
* Appliance is removable!
* Limited tooth movements possible (tipping)
* Lower appliance poorly-tolerated
What are 12 clinical tips for the use of a removable appliance?
- Fit appliance passively initially
- Demo fit and removal carefully
- Stress F/T wear except cleaning
- Warn re: speech
- No extractions until compliance confirmed
- Review every 4 weeks
- First return appointment
- Assess progress- is patient wearing it (not in a box or their pocket !)
- Appliance fit
- Wear signs – on mucosa
- Speech returned to normal
- Gentle activation of active components
Name the 8 indications for the use of a removable orthodontic appliance?
- Alignment of mesially-inclined canines
- Crossbite correction
- Overjet reduction
- Overbite reduction
- Eliminate occlusal interferences
- Adjunct to fixed appliances
- Space maintenance
- Retention
Name the 2 contraindications for removable orthodontic appliances?
Multiple tooth movements
* Complex tooth movements required
1. Intrusion/extrusion
2. Bodily movement
3. De-rotation
What is the definition of a functional orthodontic appliance?
‘Removable or fixed orthodontic appliances which use
forces generated by the stretching of muscles, fascia
and/or periodontium to alter skeletal and dental
relationships
What are the benefits of using a functional orthodontic appliance?
- Growing Patients
- Correct Malocclusions of Skeletal Origin
- May modify growth ? ?
- Commonly used in Class 2 patients with mandibular retrognathia.
- Hoping to enhance mandibular growth/restrain maxillary growth
- Treatment approach often referred to as ‘Growth Modification’
What situation is best for a functional orthodontic appliance?
- Class 2 malocclusions-
- Class 3 malocclusions (Less common)
Describe an ideal functional orthodontic appliance patient?
- Growing patient
- Class 2 div 1 malocclusion (or Class 2 Div 2 )
- Mandibular Retrognathia
- Average or reduced vertical proportions
- Increased OJ/OB
- (Well aligned arches) also crowded cases as first stage treatment
Explain how to construct a functional appliance?
- U + L Alginate impressions
- Working bite
- Teeth out of occlusion
- Postured forward (the facial musculature is stretched
and forces are generated)
Explain how to take a working bite for a functional appliance?
- Patient postures to Class 1 or edge to edge
- Record the postured occlusion with wax or silicone registration paste
Name 3 types of mode of action for rothodontic appliances?
- Dentoalveolar (Dental Effects)
- Tipping movements
- Eruption guidance
- Skeletal (Orthopaedic or Growth Effects)
- Restriction of maxillary growth
- Increased rate of mandibular growth
- Remodelling changes in the TMJ
- Modification of soft tissue activity
When is dental tipping most effective?
- Typical Class 2 div 1
- Upper incisor retroclination
- Lower incisor proclination
What is the definition of eruption guidance?
- Achieved with bite planes/capping
- Anterior
- Posterior
Produce - Differential eruption
- Inhibits eruption of upper posteriors
- Encourages mesial eruption of lower posteriors (Class 2
correction)
What is the defintion of skeletal mode of action?
- Enhanced Mandibular
Growth ? - Elongation is brought about
by deposition at the condyle
and the posterior border of
the ramus.
What is the definition of modifying soft tissues?
- Lip competency
- Changing the linguo-facial muscle balance
- Shields
- Screens
- Teeth erupt into a position of balance
WHich modes of action do functional appliances use?
- Eruption guidance
- Bite planes
- Mandibular repositioning
- Working bites
- Altering soft tissue balance
- Shields and modifying lip activity
Name the 3 classifications for functional appliances?
- Tooth borne (‘Twin block’)
- Mostly dental tipping
- Good retention
- generally well tolerated
- Soft tissue borne
- Less retention
- Difficult to achieve 24 hr wear
- Fixed functionals
Name 3 examples of tooth borne functional appliances?
- Twin Block
- Frankel
- Bionator
- Herbst
Describe a twin block functional appliance? - retention?
- Tooth borne via Clasps
- Most commonly used
- Well tolerated
- F/T wear possible
- In 2 parts, one upper, one lower
- Bite blocks posture the mandible forward
Describe a frankel functional appliance? - dentition type? soft tissue? probelms?
- Soft tissue borne appliance
(‘Monobloc’) - Good in mixed dentition
- Tooth loss does not affect retention
- Good when soft tissues significantly
contribute to the malocclusion - Expressive lower lip, lip trap
- Problems : bulky, P/T wear only and
breakages+
How to maximise the success of a functional appliance?
- Keen patient and family support
- Mild / moderate skeletal problem
- Patient actively growing
- Coordinate treatment with pubertal growth spurt
- Boys age 12-14
- Girls age 11-13
Do functional appliances grow mandibles?
- Controversial
- Early studies (Animal) suggested significant skeletal effects
- Recent RCTs suggest mainly dental effects 90% and 10 % skeletal
- Large individual variation in response
- Difficult to predict
Explain why to use a functional appliance to correct an increased overjet?
- Reduce risk of trauma
- Improve profile
- Help to allow lips to become competent
- Improve smile aesthetics
- Makes subsequent fixed orthodontics easier or can
even be the only treatment required
What is the definition of a fixed appliance?
- ‘Orthodontic appliance that
is ‘fixed’/attached to teeth’. - Many different systems /lots of
manufacturers
Describe the differences in force betweeen fixed and removable appliances?
Bodily movement: - 1 area of tension
- Heavier forces
100-150 gms
Tipping: - different areas of tension (2)
- Lighter forces 25-
30 gms
Name the 7 indications for the use of fixed appliances?
- Multiple tooth movements
- Space closure with bodily movement
- Intrusion/extrusion of teeth
- Rotation correction
- OB control with incisor intrusion
- Mild to moderate skeletal discrepancies (camouflage treatment)
- Severe Skeletal Discrepancies (+ Surgery)
Name the advantages and disadvantages of using a fixed appliance?
Advantages:
* Treating complex cases
* High standards of finishing
* Wear co-operation is not as essential as with removable appliances
but still OH and diet care !
* Less bulkier than removable appliances
* Do not affect speech
Disadvantages
* Diet restriction and meticulous OH
* Can cause iatrogenic effects (decalcification)
* Cause Orthodontic root resorption (shortening)
* Require special skill and training
* Require close monitoring
Describe the differences between Fixed and Removable?
Fixed:
- Bodily Movement
- Multiple tooth movements
- Rotations corrected
- OH more difficult
- Less Co-op ??
Removable:
- Tipping movements only
- Simple tooth movements
- Rotations not corrected
- OH easier (Removable)
- More Co-op (Wear compliance)
Name the components of fixed appliances?
Brackets
Archwire
Elastic ligature
What is the defintion of a bracket?
‘Handles on the teeth’ – control tooth position in combination with
archwire.
* 0.022’’ (inch) slot width size
commonest
* 0.018’’ (inch) more common in
past
* Slot design specific for each tooth
(prescription)
Describe the material of a bracket?
- Base of bracket
- Curved to fit each tooth
- Mesh base / retains composite
resin - Pre –coated (APC) with
composite . - Non pre-coated
Name the 7 bracket types?
- Metal – standard SWA brackets ↑
- Metal – Self ligating
- Metal- ‘tip-edge’
- Aesthetic Systems
- Ceramic
- Lingual
- (Aligners)
What are the benefits of self ligating brackets?
- Claims by manufacturers
- Quicker treatment
- Allows expansion/favours non-extraction tx
- Controversial as no evidence to support
- Studies / RCTs
- No difference Tx time
- ? Longer appt intervals
Describe a self ligating bracket type?
- Self Ligating
- eg‘Damon’, Speed, Innovation,
Smartclip - Active or Passive clip or gate
- Less friction cf normal ligation
What is the definition of tip edge brckets?
- Different tx philosophy
- 2 stage tooth movement
- Easy tipping – bracket ‘cut away’
design - Tip crowns and then upright roots
- Lighter on anchorage
What is the defintion of a lingual bracket type?
- Lingual
- ‘Incognito’ 3M system
- Expensive
- Cast Gold
- Customised for each tooth
- Bonded – indirectly with
preformed trays - Different instruments
- Archform shape -‘mushroom’
Explain the process to bond brackets to the teeth?
- Isolate
- Pumice/Prophylaxis
- Acid Etch (Phosphoric acid)
- Irrigate/Dry
- Apply Bonding agent
- Place bracket with composite resin on bracket base
- Remove excess composite
- Light Cure
What is the definition of an orthodontic band?
- Now – used on molars
- Different sizes
- Cemented with G.I.C
- Separators / 1 week before
placement - Can pre-select on model
- Cemented with glass ionomer
cement or light cured compomer - Glass ionomer / fluoride release
What is the definition of an archwire?
- Interaction archwire/bracket slot → tooth movement
- Archwire Variations
- Shape
- Size
- Alloy type
Describe the different types of archwire shapres?
- Round
eg .014 Niti - Square
eg .020 x .020 NiTi - Rectangular
eg .019 x .025 NiTi
Name the 3 alloy types of archwire?
- Nickel Titanium
- Stainless Steel
- B-Titanium (TMA)
What is the definiion of NiTi archwire alloy?
- Thermally active / non thermally
active - Super-elastic
- increased Flexible
- Shape memory
- Initial alignment stages of
treatment
What is the defintiion of stainless steel archwire?
- increased Stiffness
- increased Rigidity
- decreased Flexibility* - if multistrated it increases
- Working archwires
- Levelling
- Space closure
- Finishing (add bends)
What is the definition of Beta - Titanium archwire?
- Beta – Titanium (TMA)
- Half way between NiTi and SS
- Some flexibilty but more rigid
than NiTi - Useful finishing stages of
treatment eg adding torque or
bends to archwire