Interceptive Orthodontics 1 Flashcards
what is present in the oral cavity at birth
gum pads
what is the sequence of eruption of deciduous teeth
a > b > d > c > e
lowers before uppers
what are three differences in the primary dentition compared to the permanent
incisors more upright
spaced
wear
colour
what are arthropoid spaces
spaces mesial to upper deciduous canines and distal to lower deciduous canines
what are natal/ neo-natal teeth
teeth present at/ around time of birth
what are problems with natal/ neo-natal teeth
if mobile - inhalation risk
causing difficulty with breast feeding
what is the pre-eruptive phase
starts when the crown starts to form and ends when crown formation is complete
what is the eruptive phase
starts as soon as the root starts to form and ends when teeth reach occlusal plane
split into intra-osseous and extra-osseous stages
what is the post-eruptive phase
tooth movement/ continued eruptive movement that occurs extremely slowly
where is movement of tooth crowns kept to within the pre-eruptive phase
bony crypts
what occurs in the eruptive phase
relative position of deciduous and permanent teeth alter due to eruption of deciduous teeth and increase in height of alveolar bone
in the eruptive phase what does tooth movement occur in response to
positional changes of neighbouring crowns
growth of the mandible and maxilla
resorption of the deciduous tooth roots
what is the intra-osseous part of eruptive phase
starts with root formation - proliferation of epithelial root sheath and continues with production of pulp and dentine
what is the second stage of intra-osseous phase
movement of the developing tooth in an occlusal or incisal direction
what is the third stage of the intra-osseous phase
reduced enamel epithelium fuses with oral epithelium
what is the first stage in the extra-osseous phase
penetration of the tooth’s crown tip through the epithelial layers
what is the second stage in the extra-osseous phase
crown continues to move through the mucosa in an occlusal direction until it contacts the opposing tooth
what is the third stage in the extra-osseous phase
environmental factors - pressure from lips, cheeks and tongue influence final position
what is the eruption pathway
degeneration occurring within the dental follicle, blood vessels decrease, nerve fibres break up
what occurs in the periphery of the eruption pathway
other fibres are formed from the dental follicle - GUbernacular cord - guides the teeth to erupt into oral cavity
what is thought to guide the teeth to erupt into the oral cavity
Gubernacular cord
why do teeth erupt without patients shedding any blood
because there is no blood vessels or nerves in the eruptive pathways
what occurs to the tissues that fuse together when the tooth erupts
they go down and attach to the ACJ - forms attached gingivae
what is the post-eruptive phase in response to
growth of the growing alveolar bones and jaws
attrition and abrasion
what does proximal surface tooth wear lead to
mesial drift
what is over-eruption
continuous eruption in response to missing opposing teeth
what is tooth eruption likely caused by
root formation
remodelling of alveolar bone
development of PDL
what structure plays a key role in modulating cellular activity in tooth eruption
dental follicle
what is the role of the dental follicle during tooth eruption
reosrption of bone overlying tooth
connective tissue degradation and created eruption pathway
promotes bone growth at base of the tooth
provides traction forces within PDL
contributes to root formation (via ectomesenchymal cells)
when is the perfect time to extract a deciduous tooth to encourage eruption of permanent successor
when the permanent root is about 1/2 to 2/3 formed
definition of interceptive orthodontics
any procedure that will reduce or eliminate the severity of a developing malocclusion
what age does the early mixed dentition go up to
age 8
what age does the late mixed dentition go up tp
age 13
how do permanent incisors develop in relation to primary teeth
palatal/ lingual
what are three ways in which space is gained for the permanent dentition
increase in width due to lateral growth of jaws
upper incisors erupt into a wider arch
leeway space
what is the leeway space in the upper arch
the length of deciduous canine to deciduous E is longer than the length of the permanent canine to the 5
1-1.5mm additional space
what is the leeway space in lower arch
the length of deciduous canine to deciduous E is longer than the length of the permanent canine to the 5
2-2.5mm
what value of diastema will close on its own
less than 2.5mm
what are the three things you need to be looking for when looking at deciduous tooth eruption
age of eruption
sequence
symmetry
when should the contralateral tooth erupt
within 6 months
why might a FPM fail to erupt
could get stuck behind the distal cusp of the E
why might a FPM fail to erupt
stuck behind the distal cusp of the E
why might central incisors not appear
supernumerary tooth in the way
trauma to primary tooth while permanent tooth is developing
what would be the preferred radiographs to take to investigate a missing central incisor
anterior occlusal maxillary
periapical
what are the treatment options for an unerupted central incisor
remove primary teeth and supernumeraries
create and maintain space
monitor for 12 months
expose/ bond gold chain and apply ortho traction
what are the problems with early loss of deciduous teeth
localised crowding
what is a balancing extraction
removal of tooth from the opposite side of the same arch - maintain symmetry
what is a compensating extraction
removing tooth from opposite arch - maintain buccal occlusion
how would you manage an early loss of an A or B
no balancing extraction or compensating
how would you managed an early loss of a C
balance extraction
how would you manage early loss of a D
no balancing or compensating
how would you manage early loss of an E
no balancing or compensating
consider space maintainer so the 6 doesn’t tip forward
what are two types of space maintainers
removable
fixed
when is the ideal time to asses FPM for prognosis
8-9 years
what is the extraction of FPMs depending on
age of patient/ stage of dental development
degree of crowding
malocclusion type
GA or LA
for a gross caries FPM what is the best long term treatment in a class I case
if extracting lower take the upper
dont balance
if extracting upper dont need to take the lower
when is it best to remove FPMs
when second permanent molar bifurcation is starting to calcify
what are the two types of crossbites
anterior and posterior
if there is displacement on closure = IOTN
when would a patient definitely need treatment for posterior crossbite
if the displacement is more than 2mm
what 8 things should tell a patient after fitting an URA
wear full time
keep teeth and appliance clean
use a daily fluoride mouthwash
avoid sugary food and drinks
avoid hard sticky foods
remove for some sports
initially speech will be affected
who to contact if patient experiences problems
