10. Interceptive Orthodontics Flashcards
Definition of inceptive orthodontics
An extension of preventive ortho
- Occurs in primary or transitional dentition
- Used to reduce the severity of the malformation and mitigate its cause
- Doesn’t eliminate the possibility for future comprehensive therapy
When multiple teeth are in an anterior cross bite what are the two different skeletal occlusal schemes
- Pseudo class III
- True Class III
How can you recognize a pseudo class III clinically
- Occlude in end to end
- Slides into crossbite
Multiple teeth in a crossbite suggests what
skeletal component- need ortho referral
Reasons a tooth erupts into a cross bite
- Trauma to primary tooth(can cause ankylosis making exfoliation more difficult)
- Pulpectomy on primary tooth (more difficult for erupting tooth to resorb the root)
- Mesiodens/supernumerary
- Crowding
- Tooth erupts end to end with lower incisor and deflects into crossbite
- Class III skeletal relationship
What are the three reasons to treat a single tooth anterior cross bite
- Puts lower incisor at risk of recession
- If pt occludes end to end can chip/traumatize the incisors
- Esthetics
Treating a single tooth anterior cross bite becomes difficult when
there is not enough room on the maxilla to move the incisor forward (or lingually if we need to move the lower incisor)
What are the options for treatment of an anterior single tooth crossbite (interceptive tx)
Fixed
-2x4 (2 molars and 4 incisors)
Removable
-Hawley with Z-spring
Described the fixed 2x 4 appliance
- Brackets on four anterior teeth
- Molars are anchors and have occlusal stops (this opens the bite to help move the upper incisor forward without interference from lower teeth)
Describe the Hawly with Z-spring appliance
- Coild on the Z-spring move the incosor forward
- Should wear 24/7
- Wraps over the occlusal surface to open the bite
- Labial bow ensures the teeth aren’t pushed too far outside the arch
What should you do treatment wise when a posterior cross bite exists in the
- primary dentition
- Mixed dentition
- Primary= monitor
- Mixed= if persists in the mixed you should treat
A unilateral crossbite typically represent a (unilateral/bilateral) constriction of the maxilla
bilateral
A midline discrepancy is indicative of
a functional shift (helps achieve MIP)
Why treat a posterior crossbite in mixed dentition
- Allow room for eruption of permanent teeth
- Early tx takes advantage of less complex interdigitation of the maxillary suture
- If a shift is present want early correction to prevent possible skeletal asymmetry
Appliances to fix posterior open cross bite
Fixed
- Hyrex/Rapid palatal expander
- Quad helix
Removable
-Schwartz Plate
Describe the hyrex rapid palatal expander
- Screw mechanism allows for gradual palatal expansion
- Fixed
- Turn screw 1 turn a day (opens 1/4 mm per turn)
- Suture will fill in with bone
Describe the quad helix
- Anchored on the 6 year molars
- Loops allow you to stretch the appliance
- Puts gentle pressure causing expansion
- Can remove to reactivate
Describe the schwartz plate
- Allows gradual palatal expansion (like the RPE)
- Easier to turn the screw because it is removable
- Compliance not as good as RPE because it is removabel
What percent of kids have a non-nutritive sucking habit beyond 3 y/o
20%
T/F Incisor position will correct itself if habit stops early enough
t
At what age would we like to see non-nutritive habits stop by 9max age)
3 (but critical when the permanent incisors are erupting)
Problems with non-nutritive sucking habits
- Anterior open bite
- Flared incisors
- Posterior maxillary constriction (can lead to posterior cross bite)
- High arched palate
- Asymmetry
- Tongue thrust on swallow
Extent of the issues from non-nutrutuve sucking habits are based on
frequency, intensity and duration
What are different treatment options to help the child break the habit
- Mavala (bitter taste spray for thumb)
- Thumb guard
- Appliance (fixed for removable ) – examples are the rake, bluegrass and crib
What is ectopic eruption
-When a permanent tooth causes either reposition of primary tooth other than the one it is supposed to replace or resorption of an adjacent permanent tooth
Ectopic eruption most commonly occurs with what teeth
- Lateral incisor (both arches)
- Maxillary 1st molar
- Maxillary canine
Ectopic eruption of the lateral incisor involves
premature exfoliation of the primary canine
Ectopic eruption of the lateral incisor often indicates what
crowding
Treatment for lateral incisor ectopic eruption
Unilateral
- Extract the other primary canine (prevent midline shif)t and LLHA with a spur
- Refer to orthodontists
Ectopic eruption of the maxillary first molar involves
mesioangular eruption position of the maxillary 1st molar
-Resorbs the distal portion of the primary 2nd molar
What percentage of ectopically erupted maxillary 1st molars self-correct
66%
Prevalence of ectopically erupted maxillary 1st molars
3-4%
What are the tx options for ectopic eruption of maxillary 1st molar
- Orthodontic separators
- Brass wire
- Ortho appliance
- Estraction of send molar with pace maintenance or future distalization of the molar
- Severe cases result in loss of primary 2nd molars and space loss
T/F once the ectopically erupted maxillary 1st moalr is corrected, the second primary molar often requires extraction due to abcess formation
F- most of the time it is fine- although it is a possibility
What is a Halterman appliance
- Used to correct ectopically erupting maxillary 1st molars
- Band on primary 2nd molar
- Button on ectopic molar
- Ortho chain to force the ectopic molar distally
What is a Shammy appliance
-Meant to distalize or derotate a maxillary 1st molar
Ectopically erupting maxillary canines are positioned in what direction
mesioangular
How many ectopic maxillary canines are positioned palatally? Labially?
Palatally= 2/3 labially= 1/3
Incidence of ectopic maxillary canine impaction is
1,5-2%
Palatal impaction of maxillary canine is suspected when
canine buldge is not palpable
Having and ectopic maxillary canine is more common when
lateral incisor is missing or small
How can you improve the eruption path of an ectopic maxillary canine
extract the primary canine
- Overlapping less than half the lateral incisor root (91% success)
- More than half of overlap with the lateral root (64% success)
- If unsuccessful the canine will remain impacted
Maxillary incisor is ectopic or impacted in _% of the population
2%
Causes of maxillary incisor impaction or ectopic are
- Supernumerary tooth
- Trauma
- Pulpal treatment of primary incisor
Treament of ectopic/impacted maxillary incisor
Impacted
-Extract supernumerary tooth or overretained primary tooth
Ectopic
- Extract overretained primary tooth
- Supernumerary tooth (consider root development of permanent incisors)
Mandibular incisors tend to erupt (labially/lingually)
lingually
Lingually erupted mandibular incisors are called
shark teeth
treatment for lingually erupted mandibular incisors
- Evaluate O and P for mobility
- Pressure from tongue typically moves 24 and 25 labially
- Extract O and P is 24 and 25 are mostly erupted and O and P aren’t mobile.
