Interceptive Orthodontics Flashcards
describe the mouth at birth
gum pads
upper arch rounded
lower arch U shaped
appear class 2
AOB
what is the age span of deciduous eruption
6 months - 2.5yrs
what is the order of eruption
a b d c e
lowers before uppers
describe deciduous teeth
incisors more upright
spaced
wear
what happens to neo-natal teeth
abnormal dental development
lower incisors present at birth
extraction if mobile/difficulty breastfeeding
what are the 3 phases of eruption
pre eruptive
eruptive
post eruptive
what is the pre eruptive phase
when crown starts to form and ends when crown formation complete/root formation about to start
what is the eruptive phase
starts as soon as root starts to form and ends when teeth reach occlusal plane
what are the 2 parts of the eruptive stage
intra osseous and extra osseous
what is the post-eruptive phase
tooth movement/eruption continues as root forms and throughout life
describe the pre eruptive phase
crowns move in jaws
mesial and distal tooth movements
what do developing crowns reposition themselves in response to
growing length , width and height of jaws
how does the position of deciduous and permanent teeth change
due to eruption of deciduous teeth and increase in height of surrounding alveolar bone
how does movement of eruptive teeth occur
in response to positional changes of neighbouring crowns
growth of mandible and maxilla
resorption of deciduous tooth roots
what is the intra osseous eruptive phase
root formation
movement of developing tooth in occlusal direction
reduced enamel epithelial fuses with oral epithelium
what is the extra osseous eruptive phase
penetration of tooths crown tip through epithelial layers
crowns continued movement through mucosa in occlusal direction until contact point
what determines the final tooth position
environmental factors like muscle forces from cheeks, lips and tongue
what is the eruption pathway
an area where dental follicle degeneration occurs during intra osseous eruption
what is the gubernacular cord
fibres formed from the dental follicle in periphery of eruption pathway
why does post eruptive movement occur
in response to increased height of growing alveolar bone and jaws
in response to abrasion and attrition
in response to loss of opposing teeth
what does proximal surface tooth wear lead to
mesial drift
what causes teeth to erupt
root formation
remodelling of alveolar bone
development of periodontal ligament
what are the roles of the dental follicle
initiate resorption of bone overlying tooth
facilitate connective tissue degradation
create eruption pathway
promote alveolar bone growth
provide traction forces within PDL
contribute to root formation
when should a deciduous tooth be extracted for a permanent tooth to be encouraged to erupt
one half to two thirds root development of permanent tooth
what is interceptive orthodontics
any procedure that will reduce or eliminate the severity of a developing malocclusion
when is interception needed in the early mixed dentition
impacted 6s
potential crowding
early loss of deciduous teeth
carious 6s
cross bites
transposed teeth
habits
when do 6s erupt
6 years
when do 1s erupt
7 years
when do 2s erupt
8 years
when do 4s erupt
10 years
when do 3s and 5s erupt
11-12
when do 7s erupt
12-13
how is space gained for the permanent dentition
increase in intercanine width through lateral growth of jaws
upper incisors erupt onto wider arc (more proclined)
leeway space
what should the leeway space on the upper arch be
1 to 1.5mm
what should the leeway space on the lower arch be
2 to 2.5mm
how do you work out leeway space
primary canine, first molar and second molar
minus
permanent canine, first premolar and second premolar
when should a diastema close
if it is <2.5mm
what are the factors of development of mixed dentition
sequence
symmetry
chronological guidelines
how do you manage an impacted first permanent molar
if patient less than 7 then wait six months
orthodontic separator
distalise first molar
extract E
distal disking of E
how can unerupted central incisors occur
supernumeraries
trauma to primary tooth causing dilaceration of permanent tooth
pathology
how do you assess an unerupted central incisor
take a case history regarding trauma
extra oral
intra oral - palpate labially and palatally
is primary tooth present and mobile/discoloured
radiograph
how do you manage an unerupted central incisor
remove primary teeth and supernumeraries
create space
monitor for 12 months
expose/bond gold chain
what does early loss of deciduous teeth cause
localised crowding
what does localised crowding effect vary with
degree of crowding present already
age
arch
tooth
what is balancing extraction
removal of a tooth from opposite side of same arch
why do we balance extractions
maintain position of dental centreline
what is compensating extraction
removal of a tooth from opposing quadrant
why do we compensate extraction
maintain buccal occlusion
how do we manage early loss of c’s
balance extraction
how do we manage early loss of e’s
consider space maintainer
what does a removable space maintainer consist of
adams clasp on 6s
labial bow
southend clasps
baseplate
mesial stop if required
what does a fixed space maintainer consist of
palatal and lingual arches
band and loop
when do we assess first molars
8-9 years
what is the decision to extract poor prognosis first molars based on
age of patient/stage of dental development
degree of crowding
malocclusion type
condition of other teeth
LA/GA
what is required for the best result when extracting first molars
7s bifurcation calcifying
8s present
class 1
moderate lower crowding
mild/moderate upper crowding
when extracting 6s what else should we extract
if lower 6 then take upper 6
if upper dont take lower
when do we treat a posterior unilateral cross bite
displacement on closure >2mm
index of orthodontic treatment need is 4c
what is on URA when fixing a posterior unilateral cross bite
hyrax screw for active component
adams clasp
base plate with post
what are instructions to patient with URA
wear full time
keep teeth and URA clean
brush after eating
use mouthwash daily
avoid sugary food and drinks
remove for sports
speech affected initially
excess salivation
what do we assess with anterior cross bites
displacement
mobility of lower incisor
tooth wear
gingival recession
what is used on a URA for anterior cross bites
z spring
what occurs once treatment has been given for anterior cross bite
over bite
how do you manage a digit habit
positive reinforcement
bitter nail varnish
glove on hand
habit breaker appliance
what URA is used as a habit breaker appliance
one piece baseplate with single goal post
how do you know if your patient is wearing their appliance
ask
did they walk in with it in
can they speak
suffering from saliva
take in and out easily
signs of wear
palatal signs - erythema
tooth moved
is active component active or passive
does it still fit
when should we aim to stop habits by
before 9 years of age
