Interceptive Orthodontics Flashcards
Interceptive treatment
- Any treatment procedure which eliminates or reduce severity of developing malocclusion
Interceptive treatment success percentage
- Fully corrected 15%
- improved 49 %
Main aim for Interceptive treatment
- Maintain midline
- Prevent development of full unit class 2 molar
- Minimise crowding
- Prevent trauma
- Psychological factor
Management of developing dentition
- Calcification dates
- Eruption dates
- Transition from primary to permanent dentition
- development of dental arches
Transition from primary to permanent dentition
- Lower incisors develop and may erupt lingual to primary incisors
- Often lower incisor crowding that will improve with inter- canine growth
- Upper permanent incisors develop palatally to primary incisors .
- if there is upper crowding the upper 2s may be palatally excluded
- Physiological spacing of upper labial segment resolves as upper 3 erupts
- Leeway space
- Flush terminal planes ( if distal surface of maxillary and mandibular deciduous second molars are in same vertical plane; then it is called Flush terminal plane like class II50) of secondary primary molars Es.
Leeway space
Leeway space of maxilla and mandible
- Different in size between C,D,E and permanent 3,4 and 5
- Maxilla 1.5mm each side
- Mandible 2-2.5 on each side
Development of dental arches
- Inter canine width
- Inter molar width
- Arch circumference
Issue may occur in mixed dentition
- Early loss of primary teeth e.g trauma, caries, permature exfoliation.
- Impacted first permanent molars (6s)
- Submerged primary molar
- Dilaceration
- Supernumerary teeth
- Unerupted maxillary incisor
- Crossbite (anterior/ posterior)
- Digit habits
- Early loss of 6s (caries, hypoplasia)
- Ectopic canines
Early loss of primary teeth e.g Trauma, caries, premature exfoliation
- Crowded case - may result in neighbouring teeth drifting into space.
- This will depend on degree of crowding, patient age and location
- Less likely to occur in spaced arches
- Effect is greater in maxilla
1- Early loss of deciduous teeth- Effect
- Primary incisors (a,b)- little effect- generally shed early
- Primary canine (C)- early Unilateral loss in crowded mouth - shift central line
- Primary First molar(D): early Unilateral loss - Central line shift + affect molar relationship+ crowding
- Primary second Molar(E): Unilateral early loss - Forward drift of 6 - Space loss for 5.
Interceptive solutions of early loss
- Balancing extraction - Extraction of same tooth on other side
- Space maintenance - early loss of E to prevent drift of 6 and loss space for the 5
Space maintainers
- Best space maintainer is tooth itself.
- GDP - Restoration / stainless steel crown
- URA
- Band and loop space maintainer
Which arch has more space after shedding primary teeth ? Why?
- lower arch because bigger teeth than upper
- Lower 6’s move forward and aim to Class I molar relationship.
What happened if lose Es early?
- 5s will erupt palatally
How can GDP prevent loss of Es ?
- By Hall technique , method of managing carious primary molars by cementing preformed metal or stainless steel crown.
Dis advantage of space maintainer
- Cost
- Compliance
- High risk of caries pt
- Can loose 6’s if caries risk is high
- Dilaceration (kinky root) (can cause by trauma and development )
2- Other reasons for interceptive extraction of primary teeth
1.1- To guide/ allow the eruption of permanent successors. E.g. Late mixed dentition - lower 1-1 palatally erupt because of Lower As.
1.2- To encourage space closure in hypodontia.E.g. Consider interceptive extraction of UCBs to encourage 3-1/1-3 contact.
- 1.3-To reduce gingival recessions.
E.g. Interceptive extractions of lower Cs if significant crowding is present and pronounced gingival recession of lower incisor.Soft tissue move incisors into neutral zone. Crowding relieved in incisor region but transferred to canine region. - 1.4 - impaction of first permanent molars. Impacted 6’s do not resolve spontaneously.
*Impaction of 6s against distal aspect of the E.
*More common in maxilla.
*2/3 of cases self correct.
*Spontaneous correction is less likely after age of 8. - Interception - Disimpaction using separation (Elastomeric/brasswire) .
- Extraction of resorbed E+/- distalisation of upper 6 with URA / sectional fixed appliance
3- Submerged / infra occluded primary molars
- Exfoliation of primary teeth occurs due to process of resorption and repair. With Resorption using winning out
-In 8-14% of children there is temporary predominance of repair - leading to temporary ankylosis
- Due to growth of surrounding bone and teeth the affected molar appears to sink down or become submerged.
Tx : Submerged / infra-Occluded primary molars Solution? Interceptive
Interceptive tx: - Removal of submerged molar may be considered if:
-Occlusal surface of molar is lies at or below contact point of adjacent teeth
- Root formation of successor tooth is almost complete
- Successor tooth is absent - depending on condition of primary tooth