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
What is the definition of a elastic modules ligature?
- Used to retain archwire
- Varied colours
What is the definition of a elastic chain ligature?
- ‘Linked’ elastic modules
- Used to space close
What is the definition of a transpalatal arch?
- Across upper arch between molars
- Soldered or removable attached to molar bands
- Increases posterior anchorage
- Maintains molar widths
What is the definition of a Nance appliance?
- Similar to TPA
- Anchors upper molar position
- Acrylic button for additional anchorage from palate
What is the definition of a coil spring?
- Orthodontic Coil Springs
- Open/closed
- Used space closure and openig
What is the definition of a Zing String (Power thread)
- Elastic thread or tubing
- Used to apply traction forces to teeth during fixed
appliance treatment
What is the definition of an expanders-RME?
- Rapid maxillary expander (RME)
- Commonly cemented with bands on 1st permanent molars and
1st premolars - Midline screw
- Activated to expand upper arch (1/2 mm per day hence ‘rapid’)
What is the defintion of an expanders-Quad helix?
- Fixed expansion appliance
- Bands on 1st permanent molars
- Has 4 circle loops (helices) to give flexibility and good range of action
What is the definition of temporary anchorage device?
- ‘TADS’
- Titanium screws
- Inserted intra-radicular alveolar
bone - Topical/LA
- Common sites- between upper 5
and 6.
Describe the 4 general categories of elastics?
- Class I – Intra-arch
- Class II – Inter –arch :To correct Class II malocclusion
- Class III – Inter –arch :To correct Class III malocclusion
- Vertical – To correct open bites
Others - Anterior cross elastics - correct dental centreline discrepancies
- Posterior cross elastics
When to be concerned about eruption pattern?
After 6 months or more in contralateral
Give a description of deciduous dentition appearance?
Incisor spacing
Tooth wear of incisors (natural attrition)
Edge to edge incisors common
Describe the deciduous dentition calcification, eruption start, fully established and sequence?
Calcification - 12 weeks in utero
Eruption starts 6-9 months
Lower - ABCDE
Upper- ABDCE
Fully established 2.5-3 years
Name the calcification times for the permanent dentition (key teeth)
What is the importance for the calcification times being delayed?
Can help identify timing and aetiology of disturbance in tooth development
Systemic:
- illness/systemic upset
Localised:
- Trauma to deciduous precursor (commonly incisor)
- Persistent pathology (dental infection)
Describe the apperance of Molar Incisor Hypoplasia?
Molar Incisor Hypoplasia (MIH)
- yellow-white chalky apperance
Describe the aetiology of chronological enamel hypoplasia?
- Systemic upset
- Metabolic disturbance
- Chronological Hypoplasia
due to systemic upset at
around 1 year of age (GI
illness)
Describe the apperance of chronological enamel hypoplasia?
reduced enamel
yellow dentine shine through
Describe the aetiology of Molar Incisor Hypoplasia?
Aetiology ? Genetic/
Systemic upset third trimester-
birth
Describe the aetiology of Enamel Hypoplasia? (localised-single tooth)
Local Factors:
* Trauma to deciduous incisor
* Second premolar due to carious second deciduous molar and
chronic infection
* (‘Turners Tooth’)
Describe the eruption times for permamnent teeth in upper and lower arches?
- Variance common (1 in 20 patients 2 SD from normal ie 12 months variation)
- Eruption pattern/sequencing important to monitor ( 6 month delay cf
Contralateral) - Females earlier (6 months)
Describe the eruption sequence for the permamnet dentition upper and lower arches?
- Upper – 61243578
- Lower - 61234578
Accomodating permanent dentition - incisor regions? describe the eruption development and changes?
Spaced primary dentition
Increased intercanine width due to transverse growth (9-10 years old)
* Permanent incisors more proclined especially upper
What is the definition of the Leeway space?
Leeway space
Permanent teeth (3,4,5) < Deciduous precursors (C,D,E)
On average:
* Mx = 1.5 mm/side
* Md = 2.5 mm/ side
What to manage a developing occlusion? 0-3 years and 3-6 years?
Deciduous Dentition
0 -3 years (erupting primary)
* Monitor Eruption
* Preventative advice / reinforcement
3- 6 years
* Retain/preserve deciduous teeth
* Future problems predictors – lack of incisor spacing, early loss of
deciduous teeth (due to caries)
Deciduous dentition anomalies? - types? and issues?
- Natal teeth : present at birth
- Neonatal teeth : soon after birth (within 30 days)
- Usually tooth of normal series/ often mobile due to little root development
- May firm up with time
- Potential Issues : trauma / Inhalation risk if very mobile
What is the definition of a fused/geminated tooth?
Fused/Geminated teeth (‘double tooth’)
* Primary dentition (usually incisor region)
* Fusion of two teeth of normal series (normal complement reduced by one unit)
* Fusion of normal tooth and supernumerary tooth
* Fusion – separate canal sytems. Gemination – single canal
* May predict anomaly in permanent dentition but not always
* May predict missing or extra tooth or smaller tooth
Name the 3 consequences of early loss of deciduous teeth?
Space Loss/ Crowding
Dental mid- Line Shifts (crowded cases)
Delayed eruption of permanent successor
What are the consequences of space loss/crowding with loss of deciduous teeth?
- Buccal segments
- Earlier the loss
- increased Upper arch (mesial drift 6)
- increased Crowded case
e.g. Early loss of 2nd DMs (Es) at 4 years of age with resulting
crowding in 2nd premolar regions at 9 years of age
(‘secondary crowding’)
What is the definition of Dental mid- Line Shifts (crowded cases) for decidious tooth loss?
- Asymmetric extractions in crowded cases
- Particularly loss of ‘Cs’
- May complicate future orthodontic tx
- Need for balancing extractions / ‘Low level Evidence’
- ? Consider when asymmetric loss of C in crowded case
e.g. LR C lost earlier than
LL C with Lower CL
shift to right
What is the definition of Delayed eruption of permanent successor for decidious tooth loss?
- early loss – less than ½ root developed of permanent- delay eruption possible
- later loss – greater than 2/3 root developed of permanent- accelerated eruption possible
What are the consequences with early mixed denition (6-9 years)
Phase of eruption of 6s and incisors
* Transitional Problems (‘normal’ development features)
* Ectopic upper 6s
* Delayed eruption of upper centrals
* Lateral incisor anomalies
* Median diastema
* Habits
* Crossbites
* Traumatic Overbite
What is the definition of transitional probelms for early mixed dentition?
May be parental concerns
* Slow eruption – may be normal eruption time variation (check for normal sequence)
* Early lower incisor crowding common- permanent incisors develope lingual to deciduous incisors
e.g. Watch for ‘over retained’ deciduous teeth
- Transitional Anterior Open Bite (as incisors erupt)
- Distal ‘fanning’ of upper lateral incisors with spacing (‘ Ugly Duckling Stage’)
- Tends to ‘self correct’ as teeth erupt
What is the definition of ectopic upper first molars for early mixed dentitions?
- Impacts under distal 2nd DM (E) with resorption of distal root
- generally asymptomatic
- Not uncommon 2%
- FH 20%
- Male = female
- Related to crowding (Arch length discrepancy)
Describe the possible management options for ectopic upper first molars for early mixed dentition?
- Observe 6 – 9 months: Some mild cases resolve spontaneously
- Trim distal of Upper E to allow 6 eruption
- Consider extraction of upper E (if grossly resorbed / symptomatic/ compromising OH around 6)
- Distalise 6 – separators (elastomeric or brass wire)
- Distalise 6 – ortho treatment – rare to consider this stage as will benefit from comprehensive ortho treatment
later
What is the defintiion of Delayed Eruption of Upper Incisors for early mixed dentition?
History may be relevant e.g. trauma to deciduous incisors
* Delayed eruption of incisor compared with contralateral (6 month delay) or
both delayed
* Careful history and clinical examination (inspect/palpate)
* Local aetiological factors
- Supernumerary teeth
- Dilacerated incisor
*Radiographs - Intra-oral views, occasionally lateral Ceph useful (dilacerated),
increasingly 3 D imaging
*Careful multi-disciplinary planning on MDT clinic with Orthodontist/Surgeon
What is the definition of supernumerary teeth? and their associations?
- 3 % incidence
- more in Boys (2:1)
- 90 % premaxilla (‘mesiodens’)
- Systemic associations
- Cleidocranial Dysostosis
- CLP
- Gardners Syndrome (Familial Adenomatous Polyposis)
Name the 4 types of supernumerary teeth?
Supplemental – resemble tooth normal series
* Conical – develop early / often erupt
* Tuberculate – develop later / seldom erupt
* Odontomes (complex/compound)
(mesiodens and dens in dens)
Name the 2 problems supernumerary teeth can cause?
- Delayed eruption
- Median Diastema
Explain the management of surgery for supernumerary teeth?
- Surgical removal of supernumerary if obstructing eruption
- If not interfering with eruption and no associated pathology may opt to monitor
- Expose and bond upper central incisor
- In past often removal only and observe
- Studies – up to 50 % failed to erupt
- Now – always bonded ‘gold chain’ to allow traction
- Followed up Ortho to apply traction (fixed)
Name and describe the aetiology for dilacerated incisors?
- Developmental (more girls)
* crown displaced labially (usually 1 incisor only)
* no enamel/dentine disturbance - Trauma (more Boys ) Intrusion of As
* crown displaced palatally
* often enamel/dentine disturbance
Which radiograph is useful to assess crown/root position?
Lateral Cephalogram
Which radiograph is useful for information on positioning and corwn/root angulation?
3 D imaging with CBCT
Explain the management for a dilacerated incisor?
- Can be challenging
- Careful Multidisciplinary planning with Ortho/Resto/Surgery input
- Assess Position/Crown form/Root position
- Consider exposure and alignment but often challenging and aesthetics
unpredictable
If alignment not feasible- - Retain until end of growth(preserve bone)
- Consider replacement with implant later
What are the 4 aetioloigcal factors causing a median diastema?
Aetiological factors
* Midline supernumerary (mesiodens)
* Small teeth (Microdontia)
* Missing teeth/hypodontia (2s)
* Proclination of ULS
( Low fraenum (no evidence cause/effect relationship)
What is the definition of a median diastema?
Gap inbetween insicors
- May be transitional and close as canines erupt
Explain the management for a median diastema?
- Accept
- Small teeth/missing teeth – when older restorative
only or ortho + restorative - Orthodontic space closure (Perm retention)
Name 2 lateral incior anomalies?
Missing Upper lateral Incisors (hypodontia)
Diminutive lateral Incisor (‘peg lateral’)
What is the definition of a Missing Upper lateral Incisors (hypodontia)?
- Common (3% pop 1 or more missing unit exc 8)
- FH/Genetic aetiology
- Isolated or part of more severe hypodontia
- Associated conditions – Ectodermal Dysplasia, CLP
- Contra-lateral tooth frequently missing or diminuitive
What associated occlsual problems can occur with missing upper lateral incisors?
- Spacing / median diastema
- Asymmetry – CL shift if unilateral
- Mesial eruption of 3 with retention of C
Explain the 2 phases for missing upper lateral incisor managment?
Mixed dentition
* Retain deciduous teeth (preserves space and bone)
* Reassure regarding future management
* Refer to specialist centre when older (around 14-15 years)
Later Management
- Careful Multi-disciplinary planning
* Space closure (crowded cases / increased OJ)
* Opening space (bridge/implant)
What is the definition of Diminutive lateral Incisor (‘peg lateral’)?
Contra-lateral small or absent
* Strong association with impaction of upper 3s
* if aesthetic concerns – could consider comp build up
* may be considered later as orthodontic extraction
What habits may contribute to Diminutive lateral Incisor (‘peg lateral’)?
- Digit /Thumb sucking
- Common in most of the world (80-90 %)
- Eskimos – 0 % …
- Majority stopped 7 years
- Emotional factors may play a part with a persistent habit
What effects can Diminutive lateral Incisor (‘peg lateral’)? have on the occlusion?
Depend on habit duration (6 hours +)
* increased OJ – U Incisors proclined and L Incisors retroclined
* decreased OB / AOB (asymmetrical)
* Narrowing Upper arch – crossbite due to lower tongue
position
What is the management for digit sucking?
- Deciduous dentition (reassure should gradually stop)
- If persists into mixed dentition (beyond 7 years)
- Encourage cessation of habit
- Gentle encouragement 1: 1 with child (demo with models)
- Simple deterrant techniques – ‘glove’ / Elastoplast on thumb
- Family supportive
- Good spontaneous improvement if stop
What other deterrent appliances can be used for chronic digit suckers?
- Persistent habit
- Patient struggling to stop
- Removable/Fixed appliances
Persistent habit/older child
*More difficult - Less spontaneous improvement
- Stability of orthodontic treatment
What is the definition of inciosrs in crossbite?
Careful orthodontic assessment
* May be related to Class 3 skeletal problem ?
* Pros/Cons of early or correct later
* Trauma to lower incisors/recession may consider
e.g. Anterior Crossbite
UL 1 with traumatic
occlusion LL1 with
recession
Explain the management of an anterior crossbite?
- Patient co-operative
- Short phase of treatment
- URA with a screw section or spring
Explain the management of an anterior crossbite?
- Patient co-operative
- Short phase of treatment
- URA with a screw section or spring
What is the definition of a traumatic OB?
- Deep OB common ( early treatment not indicated)
- Traumatic OB less common
- If soft tissue/gingival damage
- Early Treatment may be indicated
- Simple Upper Removable Appliance (URA) a with flat
anterior bite plane
Name the 4 problems with a mixed dentition at 9-11 years old?
- First permanent molars (poor prognosis)
- Canine problems
- Premolar problems
- Skeletal problems
(CLP patients ABG around 9 years of age)
Why does a mixed dentiiton at 9-11 years old affect the first permanenet molar teeth?
- Careful assessment of poor prognosis first permanent molar teeth around 9 years
- Caries/ MIH
- Longterm prognosis poor
- Decision regarding extraction optimal time
- Maximising spontaneous space closure OR
- Extraction required for orthodontic reasons
- To manage crowding or reduction of increased overjet
- BUT will need to retain 6s until eruption of 7s
Describe the careful clinical assesment for first permanent molar teeth?
- History – symptoms / previous restorations
- Radiographic assessment to check all teeth present and stage of developement (OPG
recommended) - Prognosis of all 6s
- Potential Orthodontic space requirements (Crowding / Increased Overjet)
- Refer to Orthodontic Specialist for opinion
- No Orthodontic Space Concerns (Class 1 minimal or no crowding incisor regions can
relieve PM crowding) - Maximise spontaneous space closure
- Extraction of poor prognosis 6s chronological age around 9-10 years
- All teeth present on ra`diograph
- Second permanent molar root developement started (Bifurcation forming)
Why does a mixed dentiiton at 9-11 years old affect the canines?
Ectopic eruptuin/impaction
Lower canine problems:
delayed eruption not uncommon
* Impaction is rare
* generally buccally placed
* failure to resorb deciduous
* mesially positioned (overlying laterals)
* continue to migrate
* rarely – pathology/cyst
Describe the incidence of ectopic canines?
- 1-2 % population
- More common female 70:30
- 8% bilateral
- 60% palatal ; 35 % line of arch ; 5% Buccal
Name the 5 aetiologic al factors for ectopic canines?
- Long developmental / eruptive path
- Environmental/local factors
- Lateral Incisor Anomalies : loss of eruption guidance
- Crowding common with buccally impacted canines
- Suggested genetic pattern especially with palatal impaction ( supported by link with
hypodontia/microdontia and different racial prevalence rates- more common European
population groups)
Name the 4 potential complications for ectopic canines?
- Non eruption
- Resorption (12.5 % conventional imaging; Higher rates 3 D imaging)
- Cystic Change (Rare)
- Occlusal Disturbances:
- Retained UR C due to non-eruption of UR 3 with occlusal wear and
over-eruption of LR 3.
How to clinically assess ectopic canines?
Importance of Early Detection
Clinical Assessment
* 3 ‘P’s Presence, Position and Pathology
* Inspect (Have a look)
* Palpate (Have a feel)
* Younger patients (mixed dentition)
* Palpate buccally for canines 9-10 years of age
Normal development
Upper 3s ‘bulges’ visible and palpable buccally
What signs cause concern for ectopic canines?
- Delayed eruption relative to age
- Retention of deciduous canine
- Asymmetrical eruption
- Non-palpation 10-11 years
- Tipping/migration of adjacent teeth- commonly upper lateral incisor
Consider radiographic evaluation
Name the 2 objectives for radiographic evaluation of ectopic canines?
- Determine canine position
- Check for pathology e.g. cystic change / resorption of adjacent teeth
Explain the conventional imaging technique for radiographic evaluation of ectopic canines?
- Conventional imaging
* OPG – magnification of canine if impacted palatally
* OPG and Anterior Occlusal view ( Vertical parallex technique in combination)
* 2 periapical views at different horizontal angles (Horizontal parallax technique)
e.g. Demonstration of Vertical Parallax
UL 3 magnified image on OPG and ‘moves’ apically with the tube shift (vertical parallax technique) confirming
palatally positioned. UR 3 slight occlusal ‘movement ‘ in opposite direction to tube shift suggests buccally
positioned.
Explain the 3D imaging technique for radiographic evaluation of ectopic canines?
Will give accurate image of canine positioning and evidence of resorption /
pathology
Explain the treatment options for impacted canine teeth?
Management Options for Impacted Canine Teeth
1. Early Interceptive management (10-13 years)
2. No treatment
3. Surgical exposure and orthodontic alignment
4. Surgical removal
(Transplantation)
Explain what is included for interceptive management for impacted canine teeth?
- Extraction of deciduous canine to ‘normalise’ eruption of permanent canine
- Early case series studies (Ericson and Kurol 1987)- suggested can normalise eruption
in 78 % of cases (Other studies less favourable success rates 50-60 %) - More successful with younger patients, adequate space available and displacement of
canine is less than ½ way across lateral incisor - successful in carefully selected cases
emphasize early detection, careful case selection, adequate space and
maintenance of this space and importance of follow up
risk of non-eruption and need for possible
surgical exposure and orthodontic alignment
Name the 3 premolar problems for mixed dentition in 9-11 year olds?
Ectopic eruption
Supernumerary teeth
Congenital absence
What happens to result in ectopic eruption of the first premolar? How common? What to do?
Transposition with upper canine i.e. position switch
Rare ( < 1 %)
Management – accept or orthodontic input- extraction may be option if crowding
Ectopic eruption of the second premolar - how common? Why happens? Where does it usually erupt? What to do?
Common due to crowding (secondary due to early loss of 2nd DM due to caries)
Or idiopathic (often with over-retained 2nd DM tooth)
Erupt on lingual/palatal aspect of arch (may impact)
Accept / consider removal for relief of crowding
Supernumerary premolar teeth - how common? Which patients more likely?
Rare
More common in Asian /African patients
Usually supplemental
Congenital absence of second premolars - how common? Cause? Clinical relevance?
common 3%
More often lower 5s
Genetic link
Localised or more severe hypodontia
Clinically : retained 2nd DMs (Es)
Management of retained 2nd DMs (mixed dentition)?
Depends on prognosis of 2nd DMs
Degree of infra-occlusion
In general retain Es if possible in mixed dentition (perserving space and bone)
Seek early orthodontic opinion
Future orthodontic /restorative considerations
Future options : Maintain space with restorative replacement of Es or Orthodontic space closure
Infraoccluded 2nd DMs (Es) - when is this common? What might happen? What should you monitor for?
Common with missing 5s
Loss of vertical development maybe ankylosed (adjacent teeth erupt with alveolar development)
Monitor closely for vertical change in growing patient
Infraoccluded 2nd DMs (Es) - stages?
Stage 1 (above contact point)
Stage 2 (At contact point)
Stage 3 (Below contact point)
Stage 1/2 Infraoccluded 2nd DMs (Es) - what should you do? Why?
Retain and monitor for change
Good OH/low caries risk
Stage 1 (above contact point)
Stage 2 (At contact point)
Stage 3 Infraoccluded 2nd DMs (Es) - what should you do? Why?
Infra occluded UL and LR Es
Stage 3 = Below contact points +
OH difficult/ Increased caries risk
Removal difficult (surgical)
Risk of further change
Class 2 malocclusion with increased overjet and Class2 profile - what should you do and at what age?
Consideration of growth modification with Functional appliance (Class 2 malocclusions)
Referral to Orthodontic specialist around 10-11 years
Most effective during peak pubertal growth spurt (Girls 11-12 years, Boys 12-14 years)
First premolar teeth erupted (retain twin block appliance)
Reverse overjet and class 3 profile - What to do? What to consider?
Growth modification less successful (Facemask treatment)
Main effects dental tipping (difficult to restrain growth of mandible)
Potential for continued Class 3 growth (Family history important)
Patient may opt for alignment of upper arch only in early teens accepting Class 3
Best to monitor Class 3 growth and review patients concerns when older
Describe the management of late mixed dentition/early perm dentition (12-15)?
- Continuing to monitor maxillary canine eruption and second molars
- Assessing patients malocclusion and any concerns (awareness of IOTN)
- Consider referral to orthodontist for assessment as appropriate
- Majority of routine orthodontic treatment fixed appliances at this stage
- MDT patients a little later so orthodontic treatment ‘dovetails’ with restorative and
surgical phases (end of growth) - Referral of combined orthodontic/restorative patients (hypodontia) at 15 – 16 years for
planning - Referral of combined orthodontic/surgical patients at 15 -16 years for planning
Describe the management of young adulthood dentition (16-18 YO)?
- Following MDT planning
- Start pre-restorative orthodontic treatment e.g. Hypodontia patients
- Start pre-surgical orthodontic treatment e.g. Severe Class 2 and Class 3 patients
- Restorative phase (implant placement ) at end of growing period (18-20 years)
- Surgical phase (Orthognathic surgery ) at end of growing period (18-20 years)
