Overview of Phase I Treatment and Growth Modification Flashcards
What are the three main outcomes after a first ortho checkup
- No treatment
- Regular monitoring
- Early treatment: Phase I treatment
What is the definition and features of Phase I treatment
Early or interceptive orthodontic treatment in the mixed dentition
- Limited orthodontic goals
- Limited duration
- Retention may be required
- Patient may require a second round of orthodontic treatment at a later age (permanent dentition) - Phase II
Why do some patients require Phase I treatment?
- Some problems can worsen if left untreated
- Some results may not be achievable once the face and jaws have stopped growing or if teeth have erupted
Hence, with Phase I
Phase II treatment may be less complicated and shorter
What are the general objectives of Phase I treatment?
- Guide skeletal growth
- Provide adequate space for/Guide eruption of permanent teeth
- Correct habits
- Eliminate presence/risk of trauma to oral tissues
- Improve function: Incision, Mastication. Speech
- Improve facial harmony and dental aesthetics
What are some considerations prior to Phase I treatment?
1.Patient compliance/motivation
2. Effectiveness (severity, problem type)
- Undesirable side effects (eg. too old)
2. Effects on phase II treatment
3. Overall treatment fees
4. Duration of treatment (Burnout)
5. Duration of Retention (Burnout)
At what age should reverse-pull headgear/facemask (for maxillary retrusion) be implemented?
8-10
Why do some clinicians use bone anchored maxillary protraction (connected to mini screws)?
To reduce dental effects
What is the success rate of pull reverse headgear/facemask?
255% revert back to negative OJ due to excess mandibular growth
Why is early intervention in SK class III beneficial?
- Greater orthopedic change in a shorter duration
- Earlier functional improvement
- Facial and dental aesthetics
- Avoid sequelae of anterior crossbite:
Gingival recession labial to lower incisors
Incisal wear - Psychosocial benefits (vs wearing in teenage years)
- Better patient compliance
At what age should Chincup (for mandibular prognathia) be implemented?
Under 7
What is the success rate of Chincup? and Why?
Not good :(
Small transitory improvement
- ++ force magnitude and duration
- prolonged duration of wear required
- mandibular growth is difficult to control
Continued use until growth completion may be effective
When should intervention for SK Class II be done?
- Before adolescent growth spurt is effective (75%) but no adv to during growth spurt
Only done if there are specific indications
What are the indications for SK Class II Phase I treatment?
- Risk of dental trauma
- OJ >8mm
- activity of the child - Deep overbite with soft tissue trauma
- palatal of upper
- buccal of lower - Psychosocial concerns
- Facial aesthetics
What are the appliances used in intervention for skeletal Class II patients
- Headgear - to hold max growth back + distalising effect on molars
- Removable biteplate
- Functional appliances
- Removable (Twin-block)
- Fixed (Herbst, MARA) -> non-complance dependent
At what age should constricted maxilla be intervened?
ASAP
Esp if:
1. Shift on closure
2. Constriction severe enough to reduce space within arch
With increasing age: mid palatal suture more interdigitated (dental>skeletal effects) - too late = tipping of teeth
What are the appliances used in intervention for maxillary expansions and what are the cons
Removable expander
Cons:
- Dislodges easily
- Complaince-dependent
Quadhelix or W-arch (younger pts)
- less force
Hyrax expander (Adolescents)
Cons: heavy force with rigid jackscrew
What are the benefits of correcting skeletal crossbites earlt?
- Eliminate functional shift
- Increase arch perimeter
- Achieve dentoalveolar symmetry
- Reduce attrition of teeth
- Simplify future treatment
- Avoid surgical expansion
- Avoid gingival recession
When should functional shifts be corrected?
ASAP
What are the different methods of intervention for functional shifts?
Aetiology dependent
1. Localised interference
a: Primary canines/teeth: careful equilibration (minor discrepancies)
b. Displaced tooth: removable or partial fixed appliance
2. Constricted maxilla: Skeletal expansion
3. Maxilla retrusion: Facemask therapy
Why is early correction of functional shifts important?
- To prevent adaptive remodeling - a true skeletal mandibular asymmetry or prognathia can develop
- Later correction of skeletal discrepancies may require surgery
- Dental asymmetry may result from dentoalveolar compensation during growth and eruption
- Teeth in traumatic occlusion may become mobile over time or develop gingival recession
What are the indications for early intervention for increased overjet?
- Increased risk for dental trauma
- psychosocial concerns
What are the appliances used to fix increased overjet
Dependent on etiology
1. Dental: fixed appliances
2. Skeletal or for anchorage (to retract incisors): Cervical-pull headgear
What are the indications for early intervention for deep overbite?
Dental/soft tissue trauma
Why should deep overbites not be resolved till pubertal spurt or early permanent dentition unless trauma is present?
Increase teeth for anchorage
What is the treatment for over-eruption of anteriors
2x4
2: Posterior units
4: Ant brackets
Difficult as there can be reciprocal eruption of anteriors
What are the possible aetiologias of anterior crossbite?
Skeletal:
Max retrusion
Man prognathia
Pseudo-class III (functional shift)
Dental:
Likely etiology = lack of space - lats become lingually displaceed
What are the treatment appliances for anterior crossbites
- Removable appliance: Z springs
- Banded maxillary lingual arch with finger springs
- Partial fixed appliances
What are the treatment objectives for skeletal open bite?
- To restrict vertical growth of maxilla
- To restrict (posterior) tooth eruption
Cause man to rotate downwards and backwards
What appliances are used for skeletal open bite
- High pull headgear (to 6s) +/- maxillary splint (prevent eruption of posterior teeth)
- Functional appliance with bite blocks
- Both
What is the success for treatment of skeletal open bite
:(
Facial growth continues through adolescent and post-adolescent yeras
When should skeletal open bites be treated
Control of vertical development problems is best limited to mild-moderate problems towards the end of the growth period
Treatment/retention more circumscribed
What happens if habits are stopped before eruption of teeth
Spontaneous resolution
What are the cons of habit appliance therapy
- Can leave imprint on tongue
- Can trap food and cause mouth odour
What are the habit appliances used
- Tongue crib (85-90% effective) - for both forward tongue and thumb sucking
- Bonded tongue spurs
- Blue grass appliance
How is the dental open bite fixed?
- Habit has to be ceased first
- Orthodontic correction: Sectional fixed appliances to retract flared and spaced incisors
- Expander for constricted max arch (thumb sucking)
Benefits of early treatment of AOB?
- Improved ability to incise food
- Possible resolution of selected pronunciation issues (speech = multifactorial)
- Aesthetics/Psychosocial benefits
Should mild crowding require intervention?
NO
- only for aesthics
- does not improve stability
What are mild crowding intervention options
- Disking of primary teeth (MD, large pulps must be careful)/ extracting primary canines
- Dental arch expansion
- Fixed appliances
What are moderate-severe crowding intervention options
Expansion/proclination
- Expander
- Archwire + braces
- Lip bumper - prevents lower lip contact and pressure
- Lingual arch
Distalisation of molars
- Headgear
- Pendulum appliance
- Other fixed appliances
Serial extractions
What are the indications for serial extractions?
Crowding>10mm
What is serial extractions?
Timed extractions of primary and permanent teeth to reduce severe crowding and irregularity during transition from primary to permanent dentition which allows teeth to erupt over the alveolus through keratinized tissue
Requires close monitoring and may still require phase II treatment
At what age should primary canines be mobile and there be a facial canine bulge? What should be done if none?
10
Take radiograph
What happens if there is mesial positioning of the U3
Risk of permanent incisor root resorption
What is the management for root resorption of permanent incisor due to ectopic canine?
Surgical exposure and traction of U3
OR
Extraction of U3
What does existing literature say about removal of primary canines before age 11 and its ability to normalise on palatally ectopic canines?
91% if canine crown is distal to lateral
64% if canine crown is mesial to lateral
Is rapid maxillary expansion beneficial for increasing the rate of successful eruption of palatally displaced canines
Not strong evidence
What steps to take if there is an ectopic 6
If there is minimal resoprtion:
Monitor for self correction in 6 months
Otherwise: Intervene ASAP
What interventions for ectopic 6
- Brass wire/steel spring clip seperator
- Elastomeric separator
- Band with soldered spring or bonded spring (more severe cases)
- Halterman appliance (with button on 6 and cemented band with wire distal to 6 to pull the 6 distally)
What to do if the primary E is severely compromised?
Extract
+
- Distal shoe (estimate width of second premolar)
- Space regaining (space is borderline acceptable)
- Premolar extraction (for severe space loss)
What does a pendulum appliance do?
Activates wires to move 6 distally
Should excess generalised spacing be intervened?
No unless there is severe aesthetic problem
What distance is a median diastema likely to close spontaneously?
<2mm
Can still put removable appliance
What to check for if median diastemas are >2mm
- Supernumary tooth
- Intrabony lesions
- Habits
- Missing laterals
- Thick/inferiorly attached frenum
Treatment for median diastemas >2mm
Sectional fixed appliances (not removable to prevent excessive tipping of teeth)
Treatment options for missing permanent teeth
- Open space - replacement for missing teeth (prosthesis
- Orthodontic space closure - inadequate space for prosthesis
Early treatment option for missing 5s
- Extraction of Es to allow mesial drift of 6s (7-9 yrs old)
- Autotransplantation - Best if root is 2/3-3/4 formed and there is localised crowding at other sites
- Maintain Es if good root form - maintain alveolar bone till patient is old enough for prosthesis
Early treatment option for missing 2s
Extract primary Bs
- encourage canine eruption in lateral incisor position
- maintain bone - mesialisation of 3 causes bone dehiscence
When is intervention necessary for premature loss of primary teeth?
- Which tooth is loss
- Eruption timing of successor
<6 months: NIL
>6 months: intervene
Premature loss of which teeth are important
Cs: lingual collapse of arch and/or midline shift
Es: mesial drift/tipping/mesio-lingual rotation of 6s
What are the intervention options for premature loss of C
- Lingual arch with/without spur (to prevent distal drift)
- Active if space has already been loss
- Fixed appliances
- Balancing extractions - extract contralateral C (unlikely)
What are the intervention options for premature loss of E
Space maintainer (adequate space + >6mnths):
- Removable or fixed (preferred)
- Unilateral: Band and loop
- Bilateral: Nance (Upper), Lower lingual holding arch (Lower)
How to regain lost space caused by premature loss of Es
- Nance with Collins springs
- Pendulum appliances with helix and wire
- Removable finger springs
- Active loop on lower lingual holding arch (Open = active)
- Lip bumper to push 6 backwards
Should space always be maintained?
No.
- Excess crowding
- Missing permanent teeth
- Permanent teeth about to erupt (not cost effective)
