phase i treatment Flashcards
Dental features in mixed dentition that warrant further investigation/orthodontic intervention
- Functional shift
- Reverse overjet with MAXILLARY RETRUSION (no intervention for mandibular prognathia)
- Increased overjet that poses high risk of trauma to upper central incisors
- Deep overbite with soft tissue trauma
- Difference in occlusal plane between posterior and anterior teeth
- Unilateral marked displacement
- Uni/bilateral prolonged retention of primary teeth
- Unilateral delayed eruption of primary teeth
- Ectopic 6s
- Premature loss of C/E (uni/bilateral)
- Non palpable canines at 11 years old
- Missing permanent teeth
When should the first ortho visit be
7 years old or when ortho problem is first noticed
When does phase 1 treatment occur
When patient is in mixed dentition. Short duration ~1 year, limited orthodontic goals, as patient may need second round of treatment
Rationale for doing phase 1 ortho treatment
- Shorten duration of second round of treatment
- Some problems can get worse if left untreated
- Some results may be unachievable once the face and jaws have stopped growing and teeth have erupted
Objectives of phase 1 treatment
- Guide skeletal growth
- Provide adequate space for/guide eruption of permanent teeth
- Correct habits
- Eliminate presence/risks of trauma to oral tissues
- Improve function: incision, mastication, speech
- Improve facial harmony and dental aesthetics
- Simplify future treatment
Considerations for phase 1 treatment
- Compliance/motivation
- Effectiveness
- Undesirable side effects eg too old, instead of growth modification you just get movement of teeth
- Effects on Phase II treatment — does this phase I treatment actually make phase II treatment easier and quicker?
- Overall treatment fees
- Duration of treatment —> Burnout
- Duration of retention —> Burnout
How much correction can class II growth modification achieve
Not more than 3-4mm usually
How to carry out growth modification for class II malocclusion
- Max protrusion
- Headgear
- Removable biteplate
- Disclude molars, molars erupt mesially
- Mand retrusion
- Twin block
- Herbst/MARA (fixed appliance)
What are the indications for phase 1 treatment in patient with class II malocclusion
- Risk of trauma (OJ more than 7-8mm poses increased risk)
- Incompetent lips
- Deep overbite with trauma
- Psychosocial concerns
- Facial aesthetics
When should reverse pull face mask/headgear be used?
To address maxillary retrusion (pulls the upper jaw forward)
Use from 8-10 years old, after 10 years old, may have more dental movement than maxillary protraction
What is a common source of failure in phase 1 treatment of maxillary retrusion?
Mandibular growth resulting in relapse of negative overjet
Movement of teeth instead of maxillary protraction (can be solved by using mini screws)
Why can early intervention in skeletal class III be beneficial
- Greater orthopedic change in shorter duration
- Earlier functional improvement
- Avoid sequelae of anterior crossbite
- Gingival recession labial to lower incisors
- Incisal wear
- Facial and dental aesthetics
- Psychosocial benefits
- Better patient compliance
What are the limitations of interceptive treatment for mandibular prognathia
- Prolonged duration of wear required- chincup worn from age 7 all the way to 21
- Mandibular growth difficult to control
- Small transitory improvement
What are the specific indications for two phase interceptive treatment for skeletal Class II patients
- Risk of dental trauma
- Deep overbite with soft tissue trauma
- Palatal tissue of upper incisors
- Buccal gingiva of lower incisors
- Psychosocial concerns
- Facial aesthetics
Why do you need specific indications before commencing two phase interceptive treatment for skeletal class II patients
Comprehensive treatment during adolescent growth spurt is as effective as early treatment before adolescent growth spurt
What appliances are used for interceptive treatment for skeletal Class II
- Headgear→ hold maxilla growth back, has some distalising effect on molars
- Removable biteplate→ for patients with deep overbite
- Acrylic is thicker at anterior, disclude posterior, give posterior teeth space to erupt, posterior teeth also erupt in mesial direction, so will lead to correction of molar Class II
- Functional appliances
- Removable (twin block) — forces mandible to posture forward prolong forwards to correct mandibular retrognathia
- Fixed (Herbst and MARA) — same mechanism, just that it does not rely on patient compliance
When should constricted maxilla be treated
- As early as feasibly possible
- Especially if shift on closure
- Constriction severe enough to reduce space within arch
- With increasing age: Mid-palatal suture more interdigitated.
Appliances used for constructed maxilla
Removable expander for maxillary expansion
Quadhelix/w arch
Hyrax expander
Why is quadhelix/w arch used in younger patients vs hyrax expander
Midpalatal suture not so interdigitated, less rigid appliance still effective
What are 5 benefits of correcting skeletal crossbites early
- Eliminate functional shift
- Increase arch perimeter
- Achieve dentoalveolar symmetry
- Reduce attrition of teeth
- Simplify future treatment
- Avoid surgical expansion (one of the more unstable surgeries)
- Avoid gingival recession (excessive dental expansion, movement of teeth too buccally leading to dehiscence)
Why correct functional shift early?
- Prevent adaptive remodelling
- Later correction of skeletal discrepancies may require surgery
- Dental asymmetry due to DAC
- Prevent traumatic occlusion (mobile over time, or gingival recession)
Appliances for increased overjet
- Dental etiology- fixed appliances eg MARA, Herbst
- Skeletal etiology- cervical-pull headgear→ hold maxilla growth back + headgear may be used for dental etiologies also, using the skeletal base as anchorage to distalise upper molars and eliminate molar class II
What are the early treatment options for deep overbite?
- Wait for pubertal spurt/early permanent dentition unless dental/soft tissue trauma or other indications
- Growth modification, increase eruption of posterior teeth (cervical pull head gear or biteplate)
- Overeruption of anteriors
- 2X4 fixed appliance
What are the early treatment modalities for anterior crossbite?
- Skeletal
- Maxillary retrusion→ Reverse pull headgear growth modification
- Mandibular prognathia→ leave and monitor growth
- Pseudo-class III
- Eliminate functional shift ASAP
- Dental- etiology due to lack of space
- Can choose to leave alone
- Can realign tooth
- Partial fixed appliances
- Removable appliance- Z springs
- Banded maxillary lingual arch with finger springs
What are the early treatment modalities for open bite?
- Skeletal open bite
- Restrict vertical growth of maxilla
- Restrict posterior tooth eruption
- USE high pull headgear+/- maxillary splint
- Functional appliance with bite blocks
- Dental open bite
- If habit stops before eruption of teeth, usually spontaneous resolution
- Non dental intervention
- Habit appliance therapy only if the patient wants to stop eg tongue crib, bonded tongue spurs, blue grass appliance
What can you do for early intervention of moderate/severe crowding
- Expansion/proclination
- Expander
- Archwire
- Lip bumper (neutralise force from lower lip)
- Lingual arch (procline incisors, distalise molars)
- Distalisation of molars
- Headgear
- Pendulum headgear (use palate and premolars as anchorage)
- Serial extractions
- Skeletal class I crowding >10mm
- Timed extraction of primary and permanent teeth →reduce crowding and irregularity during transition
- May still require Phase II treatment
What is a sign that indicates surgical exposure and orthodontic traction of permanent 3s
- If permanent incisor root resorption has occurred, should extract primary canines and expose permanent 3s surgically
- Extracting upper primary canines may be sufficient for permanent 3s to erupt
- Removal of primary canines before age 11 will normalise palatally ectopic canines
At what age should you extract Es to allow mesial drift of 6s in the case of missing 5s
Age 7-9
