Interceptive Ortho Flashcards
1
Q
describe dentition at birth
A
- gum pads
- upper rounded
- lower U shape
- often appear very class II
- AOB
2
Q
decidious dentition features
A
- incisors more upright
- spaces
- wear
3
Q
what is natal/neonatal teeth and management
A
- abnormal dental development
- lower incisors most common tooth present at, or just after, birth
- extract if mobile and risk of inhalation or causing difficulty with breastfeeding
4
Q
tooth eruption process/phases overview
A
- re-eruptive phase: starts when crown starts to form and ends when crown formation complete/root formation about to start
- eruptive phase: starts as soon as roots start to form and ends when teeth reach occlusal place
- post eruptive phase: tooth movement/eruption continues as root forms and also throughout life
5
Q
describe pre-eruptive phase
A
- from crown starts to form until crown formation complete
- developing crowns move constantly within jaws - small mesial and distal tooth movements
- developing crowns reposition themselves in response to increasing legnth, width and height of jaws
- movement of tooth crown is contained within the bony crypts
6
Q
eruptive phase overview
A
- relative position of deciduous and permanent teeth alter - due to eruption of deciduous teeth and increase in surrounding aveolar bone height
- movements occcur in response to:
- positional changes of neighbouring crowns
- growth of the mandible and maxilla
- resorption of decidious tooth roots
7
Q
eruptive phase
intra-osseous overview
A
- root formation: proliferation of epithelial root sheath and production of dentine and pulp
- movement of the developing tooth in an occlusal or incisal direction (slow - several months)
- reduced enamel epithelium uses with the oral epithelium
8
Q
eruptive phase
extra-osseus
A
- penetration of the tooths crown through the epithelial layers (fast - 1/2 weeks)
- crown continues to move through the mucosa in an occlusal direction until it contacts the opposing tooth (slow - several months)
- environmental factors (muscle forces from cheeks/lips/tongue) determine final tooth position
9
Q
post-eruptive phase overview
A
- movement after tooth has already reached the occlusal plane
- occurs in response to increases in eight of growing alveolar bone and jaws
- in response to attrition and abrasion - tooth erupts slightly
- proximal srface tooth wear leads to mesial drift
- in response to loss of opposing teeth = overeruption
10
Q
theories of tooth eruption
A
- multifactorial
- root formation
- remodelling of alveolar bone
- development of the periodontal ligament
- genetic influence?
- signalling between dental follicle and reduced enamel epithelium
- signalling cascade of cytokines: IL1; RANKL/OPG
11
Q
roles of the dental follicle
A
- initiates resorption of bone overlying tooth
- facilitates C degredation and creates eruption pathway
- promotes alveolar bone growth at base of tooth
- ectomesenchymal cells from follicle contribute to root formation: cementoblasts and cementum
12
Q
interceptive orthodontics tx overview
A
- utilise tooth eruption to minimise or eliminate severity of a developing malocclusion
- permanent teeth can be encouraged to erupt if deciduous tooth X at correct stage - 2/3 root development of permanent tooth
- for example ectopic canines tx by interceptive X of decidious C ages 10-13
13
Q
early mixed dentition what may require interception tx
A
- impacted 6s
- potential crowding
- early loss of decidious teeth
- carious 6s
- cross-bites
- transposed teeth
- habits
14
Q
how is additoinal space aquired to accomodate larger permanent anterior teeth
A
- increase in intercanine width - lateral growth of the jaws
- upper incisors erupt more proclined - wider arc
- leeway space
15
Q
how much leeway space in uppers and lowers
A
- upper: 1 to 1.5mm
- lower: 2 to 2.5mm
16
Q
diastemas of what size during mixed dentition should close
A
under 2.5mm
17
Q
impacted 6s (stuck behind e etc) management options
A
- if pt <7 wait 6 months (90% self corrects)
- orthodontic separator
- attempt to distalise first molar
- extract E
- distal disking of e
18
Q
unerupted central incisor due to supernumeraries
management
A
- remove primary teeth and supernumeraries
- create space/maintain space
- monitor for 12 months if pt under 9
- if still fails to erupt or pt over 9 - expose/bond gold chain and apply orthodontic traction
19
Q
early loss of deciduous teeth management
A
- As and Bs: dont balance or compensate; little impact
- Cs: balancing extraction
- Ds: might case small centreline shift; potentiallybalance under GA?
- Es: consider space maintainer; major space loss; tend NOT to balance
20
Q
types of space maintainers
A
- passive URA: extend acrylic around teeth to prevent unwanted mesial drift +/- mesial stop if required
- fixed: band and loop; palatal and lingual arches
21
Q
first molar X most ideal result gained when
A
- 7s bifurcation calcifying
- 8s present
- class 1 av/reduced OB
- moderate lower crowding
- mild/moderate upper crowding
22
Q
6s X general rules (class 1)
A
- if extracting lower take upper (compensating X)
- dont balance X with sound tooth
- dont balance if well aligned or spaced
- if extracting upper dont need to take lower
23
Q
posterior unilateral cross bites IOTN4c
A
- > 2mm
- TREAT
24
Q
what to tell pt when we fit a URA
A
- wear full-time
- keep teeth and appliance clean: brush 2 x day minimum and preferably every time after eating
- avoid sugary food/drink and carbonated drinks
- avoid hard, sticky foods
- remove for contact sports
- initially speech affected and excess salivation
- may be sore
25
Q
digit habit management
A
- positive reinforcement
- bitter-tasting nail varnish
- glove on hand, elastoplast
- habit breaker appliance (deterrents): fixed or removable
26
Q
describe deterrent appliance
A
- URA: palatal goal post(s)
- fixed: tongue rake
27
Q
how do you know if pt still wearing their appliance
A
- ask them
- can they speak with it in
- still suffering from excess salivation?
- can they take it in/out without difficulty
- signs of wear on appliance
- has tooth moved
- does the appliance still fit
28
Q
cross-bite correction stability
A
- anterior: overbite / growth
- posterior: 50% relapse
29
Q
why treat habits early
A
- maximise potential for spontaneous corection of anterior open bite - whilst still eruptive potential for incisors
- eruptive potential = 8/9 years or root formation still incomplete
- prevent effects on vertical and transverse skeletal development which could lead to permanent skeletal change if habit persists
30
Q
digit habit management options
A
- positive reinforcement
- bitter-tasting nail varnish
- glove on hand/elastoplast
- habit breaker appliance (deterrent) fixed or removable
31
Q
example of a deterrent
A
- URA: palatal goal poast(s)
- fixed: tongue rake
32
Q
laxed mixed dentition ortho problems requiring interceptive ortho
A
- infra-occluded deciduous teeth
- canines
- overjets
33
Q
infra-occluding teeth aetiology
A
- permanent successor potentially absent
- ankylosis of primary tooth
34
Q
how to diagnose infra-occluded tooth
A
- percussion
- check for mobility
- PA or OPT: check presence/absence of successor
- ankylosis on radiograph: no PDL space/no clear lamina dura
- root resorption of primary
35
Q
infra occluding tooth management
permanent successor present
A
- monitor 6-12 months
- extract if toth below interproximan contact point
- consider X if root formation of successor nearly complete
- if extract - maintain space
- do nothing risks: permanent more ectopic; infraocclusion worsens; caries/perio
36
Q
infra occluding tooth management
permanent successor absent
A
- tx depends on crowding, level of infra occlusion and other malocclusion features
- retain primary if in good condition and consider onlay
- extract if below interproximal contact point
- if extract either maintain space for prosthetic or close space
37
Q
space maintainer options
A
- URA
- extend baseplate around
- or
- consider wire stop: either 0.6mm or 0.7mm
38
Q
upper canines normal development
A
- starts high and palatal
- migrate and lie labial and distal to root apex of laterals
- 90% palpable by age 11
39
Q
assessing delayed eruption of canines/ectopic
A
- assess from (9-)10years onwards
- should palpate by 11 years
- mobile Cs and symmetry
- angulation of lateral incisors
- radiograph if unable to palpate by 11 years
40
Q
interception of ectopic maxillary /successful when
A
- extraction of the c
- successful when:
- pt age 10-13
- canine is distal to the midline of the upper lateral incisor
- sufficient space available
41
Q
ectopic maxillary canines
risk of doing nothing
A
- permanent successor can become more ectopic
- permanent canine fails to erupt
- risk of root resorption of adjacent teeth
- risk of cyst formation around canine (rare)
- permanent canine can become ankylosed - incidence tends to increase with age
42
Q
interceptive tx options of class III
A
- growth modification: enhance maxillary growth and/or reduce mandibular growth
- protraction headgear +/- RME (rapid maxillary expansion)
- functional appliances eg reverse twin block
- camouflage with URA
- best when pt age 8-10 and needs to wear 14+ hours each day
43
Q
increased OJ why treat early
A
- risk of trauma
- appearance: bullying/pt self esteem
- more difficult to correct once pt stops growing
- > 6mm = 4a
- > 9mm = 5a
44
Q
interceptive tx class II
A
- growth modification: restrain maxillary growth and promote mandibular growth
- functional appliances: 75% dental and 25% skeletal
- twin blocks
