Ortho - Lecture 16: Ortho Ext Patterns Flashcards
Father of modern ortho
Dr Edward Angle
Has a non-extraction treatment philosophy
Dr Edward Angle
His theories:
❖ People are capable of obtaining ideal occlusion with all 32 teeth
❖ Skeletal problems can be corrected with elastics
❖ Less attention paid to facial proportions and esthetics
Dr Edward Angle
A student of Dr Edward Angle
Dr Charles Tweed
Reintroduced extraction treatment in the 1940s and 1950s to enhance facial esthetics and achieve better stability of occlusal relationships
Dr Charles Tweed
T/F: Goals/limitations of ortho treatment are
determined by soft tissues of the face, not by
the teeth and bones
True
Primary goal = _______ _______ relationships and
adaptations
Secondary goal = functional ____________
soft tissue; occlusion
How much crowding?
Ext rarely indicated
Expand arches or IPR
< 4 mm
How much crowding?
Either non-ext or ext based on soft tissue profile and gingival tissues
5-9 mm
How much crowding?
Ext almost always indicated
> 10 mm
What limits the ability to protract or retract
incisors?
Soft tissue
What can create fuller lips?
Proclining the incisors
In a pt with thin lips, large nose, and strong chin, what can prematurely age the pt?
Ext and retracting incisors
T/F: Generally, non-ext is the first choice in
borderline cases
True
What can help in maintaining alignment in
patients who may be at higher risk for relapse?
Bonded lingual retainer
What are the 3 alternatives to exts?
Move incisors facially
Expansion of arch
IPR
What are the following potential problems of?
Relapse
Perio concerns (recession, fenestration)
Open bite
Non-ext
Lip pressure increases if lower incisors move greater than _______ mm forward from their original position
2
Expansion across lower __________ is not as stable as expansion across premolars and molars
canines
What should you do for a pt with class I crowding (moderate to severe)?
Ext four 1st premolars OR
Ext four 2nd premolars
Which tx option should you choose for a pt with class I crowding (moderate to severe)?
Crowding is in the anterior, so we want to create space closest to the crowding
Ext four 1st premolars
Which tx option should you choose for a pt with class I crowding (moderate to severe)?
Want to reduce effects on soft tissue
Pts with thin lips are more susceptible to the “dished in” appearance, so we want to avoid extracting the 1st premolars to bring back the lips any further
Ext four 2nd premolars
Which tx option should you choose for a pt with class I w/ dentoalveolar protrusion?
Ext four 1st premolars
Which malocclusion?
Anterior teeth flare out during eruption
Lip fullness
Mentalis muscle strain
Lip incompetence
Class I w/ dentoalveolar protrusion
Which tx option should you choose for a pt with class I crowding or dentoalveolar protrusion?
Ext four 1st premolars
Which tx option should you choose for a pt with class I crowding w/ retrusive lips?
Ext four 2nd premolars
Which tx option should you choose for a pt with class II crowding or need for skeletal camouflage?
Ext upper 1st premolars and lower 2nd premolars
Which tx option should you choose for a pt with class II but is non-growing, has a good mandible/profile, little mandibular crowding, and 5-10 mm of excess overjet?
Ext upper 1st premolars
(if > 10 mm overjet, surgery is preferred option)
Which tx option should you choose for a pt with class III and needs skeletal camouflage?
Ext upper 2nd premolars and lower 1st premolars
Which tx option should you choose for a pt with class III but the maxillary arch is not crowded and the mandibular arch has moderate/severe crowding?
Ext lower 1st premolars or single lower incisor
What can help shift the dental midline to the center of the face?
1-2 premolars ext on one side only
What helps correct class II and/or close an open
bite and relies on third molars to erupt later and take the second molar position?
Ext 2nd molars
(rarely done)
The timed sequence of extraction of primary teeth and, ultimately, permanent teeth to relieve severe crowding (>10 mm)
Serial exts
Increase available space for erupting permanent teeth by extracting certain deciduous teeth
Serial exts
Allows teeth to erupt over the alveolus and
through keratinized tissue (rather than B/L
displacement)
Serial exts
Originally advocated as a method to treat
severe crowding; goal was to eliminate any future need for appliance therapy
However, nearly all patients still require fixed
appliance therapy for ideal results
Serial exts
What is the serial ext pattern?
Primary canines
Primary 1st molars
1st premolars
What is indicated if the following are present?
-Severe mesial tipping or ectopically erupting
permanent 1st molars
-Early loss of mandibular deciduous canines
-Fanned out U/L permanent incisors due to crowded or unerupted permanent canines
-Abnormal resorption of primary teeth
-Permanent cuspids erupting buccally
Serial exts
