Interceptive Orthodontics 2

Question 1

name 4 possible reasons for interception in the early mixed dentition

Answer 1

impacted 6s
unerupted central incisors
early loss of deciduous teeth
carious 6s

Question 2

discuss impacted 6s and how this might be managed by orthodontic intervention (3)

Answer 2

occurs if FPM gets stuck beneath the distal portion of the E and fails to fully erupt
management: if patient under 7 wait 6 months and hope for spontaneous resolvement, place orthodontic separator between contact point of 6 and E to create space, Distal disking of E (remove some enamel on distal portion to create space)

Question 3

what is the most common reason for unerupted central incisors

Answer 3

supernumerary in the way

Question 4

management of unerupted central incisors

Answer 4

try and define cause e.g suprnumerary , trauma
remove any primary or supernumerary teeth , create and maintain space , monitor for 1 year if patient under 9 (immature root apex)
if over 9 or more than 1 year has passed expose and bond gold chain to unerrupted tooth and apply orthodontic traction

Question 5

what deciduous teeth require a balancing extraction if they are lost early

Answer 5

c and d
balancing extraction - removal of tooth from opposite side of same arch to maintain centreline

Question 6

what is the most ideal situation if needing to extract carious first permanent molars

Answer 6

bifurcation of 7s beginning to calcify, 8s present, class I occlusion with moderate crowding

Question 7

what are the general rules, for class I occlusions, when extracting 6s early

Answer 7

if extracting a lower take the upper to (compensating extraction - prevents overeruption)
if extracting an upper a compensating extraction of the lower is not required
no need to balance if contralateral tooth is sound

Question 8

IOTN

Answer 8

index of orthodontic treatment need
tells us whether a patient needs treatment, is borderline or does not need treatment for functional purposes

Question 9

short term and long term issues of a developing posterior cross bite

Answer 9

short term - permanent teeth will also erupt into a cross bite
long term - risk of TMJ problems

Question 10

mandibular displacement from a cross bite of what size indicates need for orthodontic treatment

Answer 10

more than 2mm

Question 11

why is it recommended that posterior crossbites are ‘overcorrected’

Answer 11

theyre prone to relapse, around 50% will relapse

Question 12

name 7 things a patient should be told when we fit a removable appliance

Answer 12

• wear full time
• keep teeth and appliance clean, brush minimum twice daily, preferably everytime after eating
• should be worn for eating but not brushing
• use a daily fluoride mouthwash
• avoid sugary foods and drinks
• avoid hard sticky foods
• may want to remove for contact sports
• speech will initially be affected but this will improve
• excess saliva will initially be produced but this will improve
• eating might feel awkward

Question 13

anterior cross bites put a jiggling force on the lower incisors , what consequences might this cause

Answer 13

tooth mobility
tooth wear
gingival recession

Question 14

what type of bite is desirable for patients getting their anterior cross bite corrected

Answer 14

over bite
acts as a retainer that stops anteriors drifting back to their original position and the new bite relapsing

Question 15

name 4 possible management strategies from least to most interventive that might be used to stop a child digit sucking

Answer 15

positive reinforcement
bitter tasting nail varnish
glove on hand or elastoplast
habit breaker appliance - fixed or removable

Question 16

habit breaker appliances

Answer 16

used to break habit of digit/ thumb sucking
on their own , habit breaker appliances are passive , have anterior and posterior retention, a base plate and a metal goal post (small piece of metal that feels uncomfy when patient tries to suck digits

Question 17

why might a dual function appliance be used in children with a digit or thumb sucking habit

Answer 17

they are prone to developing an AOB, retroclined lower incisors and a narrowed upper arch which can result in a unilateral cross bite
A habit breaker appliance with an added active component to widen the maxillary arch may be useful (contains goalpost and active component)

Question 18

give 5 ways you might assess if a patient has been wearing their removable appliance

Answer 18

ask them
did they walk in wearing it
can they speak with it in
are they still suffering from excess salivation (this should settle if its being worn )
can they take it in and out easily
does the palate show signs of it being worn (erythema)
has the tooth moved / is the active component now passive

Question 19

what were infraoccluded deciduous teeth previously known as

Answer 19

submerging teeth

Question 20

aetiology of infra occluded teeth

Answer 20

ankylosis of primary tooth, surrounding alveolar bone continues to grow and the primary tooth gets left behind

Question 21

diagnosis of infra occluded primary tooth

Answer 21

percussion - ankylosed teeth will have dull percussion tone
check for mobility
radiographically ankylosed teeth will have no PDL space and no clear lamina dura

Question 22

management of infra occluded deciduous teeth

Answer 22

monitor for 6 -12 months
extract if primary tooth is below the interproximal contact point
consider extraction if successors root formation is near completion
(if extracting remember to maintain space)

Question 23

risks of doing nothing to a infra occluded primary tooth

Answer 23

permanent successor can become ectopic
infra occlusion worsens and adjacent teeth tip making ankylosed tooth inaccessible for extraction
caries and perio due to oral hygiene difficulties

Question 24

at what age should upper canines be palpable

Answer 24

almost all should be palpable by 11 years old , if not radiograph to investigate

Question 25

management of ectopic maxillary canines

Answer 25

extract Cs and maintain space
if canine has not passed midline of lateral incisor , 90% chance of spontaneous improvement in positioning
if canine has passed midline of laterals this reduces to 60%
most likely to be successful if patient is 10-13 years old

Question 26

when assessing overjets, increased and reversed, what must be assessed

Answer 26

is the aetiology dental or skeletal

Question 27

what are the maximum proclinations and retroclinations of incisors before stability becomes at risk
(think management of class IIIs)

Answer 27

max upper incisors can be proclined is 120 degrees (with regards to the frankfort plane)
max lower incisors can be retroclined is 80 degrees
(with regards to the mandibular plane)
if pt already has these angulations another method of management must be considered

Question 28

management of a reverse overjet (class III)

Answer 28

• growth modification - enhance maxillary growth and/or reduce mandibular growth via protraction headgear / rapid maxillary expansion / functional appliance
• camouflage effects using a URA to tip teeth

Question 29

why should increased overjets be treated early

Answer 29

increased risk of trauma
incompetent lips
appearance - self esteem , bullying
more difficult to achieve correction once patient has stopped growing

Question 30

management of increased overjets

Answer 30

growth modification via functional appliances aiming to restrain maxillary growth and promote mandibular growth