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