Overview of Phase 1 Treatment and Growth Modification Flashcards
Learning Objectives
When is the 1st orthodontic check-up indicated?
- When an orthodontic problem is first recognised
- No later than age 7
American Association of Orthodontists
What are the three main outcomes of the 1st orthodontic check-up?
- No treatment
- Regular monitoring
- Early treatment: Phase 1 treatment
Characteristics of a Phase 1 Treatment
- Interceptive orthodontic treatment at mixed dentition stage
- Limited orthodontic goals
- Limited duration
- Retention may be required
- Patient may require a 2nd round of orthodontic treatment at a later age
Why do we need Phase 1 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
- Treatment at a later stage may be shorter or less complicated
General Objectives for Phase 1 Treatment
- Guide skeletal growth
- Guide eruption of permanent teeth
- Correct habits
- Eliminate risks of trauma to oral tissues
- Improve function: Incision, mastication, speech
- Improve facial harmony and dental esthetics
Considerations before starting Phase 1 treatment
- Compliance
- Effectiveness (Severity and problem type)
- Undesirable effects
- Effect on phase II treatment (need, duration, complexity) - Overall treatment fees
- Duration of treatment and retention
What are the possible SKELETAL problems that require Phase 1 treatment?
- Skeletal Class IIIs (Maxillary retrusion or Mandibular prognathia)
- Skeletal Class II (Maxillary protrusion and mandibular retrognathia)
- Constricted maxilla
What are the possible DENTAL problems that require Phase 1 treatment?
- Functional shifts
- Increased overjet/ deep overbite
- Anterior crossbite or Open bite
- Crowding or excess spacing
- Ectopic eruption
- Missing permanent teeth or premature loss of primary teeth
What is the Phase 1 treatment for Maxillary Retrusion?
Reverse-pull headgear/face mask
What is the Ideal Timing to start Reverse-pull headgear/face mask for maxillary retrusion?
8-10 years old
> 10 year old not so effective (Kim et al 1999)
10-14 year old: Still some orthopedic effects (Kapust et al. 1998)
After 4 years, 25% reverted to negative OJ due to excess mandibular growth (Ngan et al 1997)
Why is early intervention of SK Class III beneficial?
- Greater orthopedic change in shorter duration
- Earlier functional improvement
- Avoid gingival recession labial to lower incisors (due to anterior crossbite)
- Incisal wear (due to anterior crossbite)
- Facial and dental esthetics
- Psychosocial benefits
- Better patient compliance
What age is ideal to start a chin cup?
Under 7 years old
What is the success rate of chin cup for mandibular prognathia?
Not very successful
Small transitory improvement but
- Prolonged duration of wear required
- Mandibular growth difficult to control
Continued use until growth completion may be effective (Mitani 2007)
Effectiveness of early treatment of Skeletal Class II patients
BEFORE adolescent growth produced favourable growth changes in 75%
DURING adolescent growth spurt no significant advantage
UNLESS there are specific indications
Indications of early treatment for Skeletal Class II patients
- RIsk of dental trauma
(>8mm overjet. Odds ratio=12.47) - Deep overbite with soft tissue trauma
- Palatal tissue of upper incisors or buccal gingiva of lower incisors - Psychosocial concerns
- Facial esthetics
Appliances used for Class II Skeletal patients
- Headgear with or without removable biteplate → Protrusive maxilla
- Functional appliances such as removable (twin-block) or fixed (Herbst, MARA) → Retrognathic mandible
When should you treat a constricted maxilla?
As early as feasibly possible
Especially if shift on closure or constriction severe enough to reduce space within the arch
With increasing age, mid-palatal suture more interdigitated (Dental>Skeletal effects)
Which appliances are used for maxillary expansion?
- Removable expander
- Quadhelix or W-arch in younger patients
- Hyrax expander (heavy force with rigid jackscrew) for adolescents
What are the disadvantages of a removable expander?
- Dislodges easily
- Compliance-dependent
What are the benefits of correcting a skeletal crossbite early?
- Eliminate functional shift
- Increase arch perimeter
- Achieve dentoalveolar symmetry
- Reduce attrition of teeth
- Simplify future treatment: Avoid surgical expansion and gingival recession (excessive dental expansion)
What is a functional shift?
CR-MI slide
What can CR-MI slide (Functional shifts) lead to?
- Pseudo-Class III malocclusions
- Unilateral posterior crossbite resulting in facial asymmetry
- Traumatic occlusion
- Gingival recession
What is the timing of intervention of Functional Shifts?
ASAP
What is the method of intervention of functional shifts?
Depends on etiology
- Localised interference: Primary canines: Careful equilibration
- Displaced tooth: Removable or partial fixed appliances
- Skeletal expansion
4.Facemask therapy
Benefits of early correction of functional shift.
- To preventive adaptive remodeling
2.Dental asymmetry may result from ADC during growth and eruption
- Teeth in traumatic occlusion develop gingival recession and become mobile over time
Larger correction of skeletal discrepancies may require surgery
What are the indications for early intervention of Increased Overjet?
- Increased risk for dental trauma
- Esthetic/psychosocial concerns
The appliances used for increased overjet are used for?
- Fixed appliances (Dental)
- Cervical-pull headgear (Skeletal for anchorage)
Indications for early treatment of deep overbite
Dental/soft tissue trauma or other indications
Management of Deep Overbite
- Skeletal: Growth modification or increased eruption of posterior teeth → Headgear and biteplate
- Over-eruption of anteriors → 2x4 (fixed appliances) → Difficult
Management of Anterior Crossbite
- Skeletal or dental etiology?
Skeletal
- Growth modification age 8-10 for maxillary retrusion
- Monitor growth for mandibular prognathia
- Pseudo-Class III: Eliminate functional shift ASAP
Dental
- Likely etiology = lack of space
Appliances for anterior crossbite
- Removable appliance: Z springs (Push tooth buccally)
- Banded maxillary lingual arch with finger springs
- Partial fixed appliances
Treatment Objectives of Skeletal Open Bite?
- Restrict vertical growth of maxilla
- Restrict posterior tooth eruption
Control posterior vertical growth: Mandible to rotate upward and forward
Appliances for Skeletal Open Bite
- High-pull headgear with or without maxillary splint
- Functional appliance with bite blocks
- High-pull headgear + functional appliance with bite blocks
Success of early treatment of skeletal open bite?
Vertical facial growth continues through adolescence and into post-adolescent years
Control best limited to mild-moderate problems towards end of growth period
Not a lot of early intervention due to questionable success
Management of Dental Open Bite
Habits stops before eruption of teeth → Spontaneous resolution
- Non-dental intervention
- Habit appliance therapy only if the child wants to stop the habit
Disadvantages of Habit Appliance Therapy
- Can leave imprint on tongue
- Can trap food and lead to mouth odour
Habit Appliance Therapy
- Tongue crib effective in 85-90%
- Bonded tongue spurs
- Blue grass appliance
Appliances used to correct Dental Open Bite
- Habit must stop first
- Sectional fixed appliances: to retract flared and spaced incisors
- Expander to expand constricted maxillary arch
Benefits of Early Treatment of AOB
- Improve ability to incise food
- Possible resolution of selected pronunciation issues
- Esthetic/Psychosocial benefits
What can be done for early intervention of dental Crowding?
- Disking primary teeth/extracting primary canines
- Dental arch expansion
- Fixed appliances
What can be done for early intervention of Mild Crowding?
1: Expansion/proclination
- Expander
- Archwire
- Lip bumper
- Lingual arch
- Distalization of molars
- Headgear
- Pendulum appliance
- Other fixed appliances
- Serial extractions
Indications of Serial Extractions
Crowding > 10mm, Skeletal Class I (Extract where crowding is at)
What are Serial Extractions?
Timed extraction of primary and permanent teeth
Purpose of Serial Extractions
- To reduce severe crowding and irregularity during transition from primary to permanent dentition
- Allow teeth to erupt over the alveolus, through keratinized tissue
When should you start early intervention of Ectopic Maxillary Canines?
Age 10 if primary canine not mobile and no observable or palpable canine bulge
Take radiograph
Management of Ectopic Maxillary Canines
- Mesial position of U3 with risk of permanent incisor root resorption (has not occurred)
- Extract U3
- Check root development of U3
- Permanent incisor root resorption has occured
- Surgical exposure and orthodontic traction of U3 or
- Extract U3
When should you intervene for Ectopic 6s?
Minimal resorption, monitor for self-correction (6months)
Otherwise intervene ASAP
Appliance used for Ectopic 6s
- Brass wire/steel spring clip separator
- Elastomeric separator
- Band with soldered spring or bonded spring
What to do for Severely compromised 7s + Ectopic 6
Extract primary tooth followed by:
- Distal shoe space maintainer OR
- Space regaining OR
- Premolar extraction
When should you intervene for Excess Generalised Spacing?
Can manage in permanent dentition unless it is a severe esthetic problem
Management of Maxillary Median Diastema
- Close spontaneously
- <2mm removable appliance
- > 2mm
- Check for supernumerary tooth or intrabony lesion, habits, missing permanent 2s, thick/inferiorly attached frenum
- Sectional fixed appliances
Phase II treatment of Missing Permanent Teeth
- Open space for replacement of missing tooth
- Orthodontic space closure
What is the early treatment for missing second premolars?
- Extract Es at 7-9 years old and allow mesial drift of 6s
- Autotransplantation if localised crowding at other sites
- Maintain Es if good root form, helps to maintain alveolar bone
What is the early treatment for missing permanent lateral incisors?
Extract primary lateral to encourage canine eruption in lateral incisor position
and maintain bone
Time is important for intervention for missing permanent teeth because?
- Directing development and eruption of permanent teeth
- Autotransplantation; Donor should have 3/4 root formed if not RCT may need to be performed in the future
What is the problem of premature loss of primary teeth?
Adjacent teeth may drift or tilt
Extent depends on degree of crowding, age, site
Considerations for intervention of premature loss of primary teeth
- Which tooth is lost
- Eruption timing of successor
What happens if there is premature loss of A or B?
Minimal consequences
What happens if there is premature loss of C?
Lingual collapse of arch and/or midline shift
What happens if there is premature loss of D?
KIV midline shift. Monitor
What happens if there is premature loss of E?
Mesial drift/ tipping/mesiolingual rotation of 6s
Objectives of early intervention for Premature loss of C
- Prevent midline shift (incisors drift distally and lingually)
- Preserve space for eruption
- Preserve arch symmetry
Intervention for Premature Loss of C
- Lingual arch with/without spur
- Active retainer if space has already been lost
- Fixed appliance
- Balancing extractions?
Intervention for Premature Loss of E
Space maintainer if there is adequate space and >6 months before permanent tooth erupts
Types of space maintainers
- Removable or fixed (preferred)
- Unilateral band or loop
- Bilateral: Nance (upper) or lower lingual holding arch
When should we not maintain space?
- Excess crowding
- Missing permanent teeth
- Permanent teeth about to erupt
