Orthodontics Flashcards

1
Q

definition of local causes of malocclusion

A

localised problem or abnormality within either arch which produces a malocclusion

due to variation of tooth number, variation in tooth size/form, abnormalities in tooth position, abnormalities of soft tissues or local pathology

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2
Q

local causes of malocclusion due to variation in tooth number

A

supernumerary teeth
hypodontia
retained primary teeth
early loss of primary teeth
unscheduled loss of permanent teeth

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3
Q

4 types of supernumerary teeth

A

supplemental
odontome
tuberculate
conical

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4
Q

4 occlusal features that can be present due to a prolonged digit sucking habit

A

anterior open bite
posterior cross bite
proclined upper anteriors
retroclined lower anteriors

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5
Q

4 methods used to dissuade a digit sucking habit

A

positive reinforcement
bitter tasting nail polish
gloves/elastoplast
habit breaking appliance

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6
Q

effect of prolonged digit sucking habit on posterior dentition

A

narrowed dental arch, changes in palatal shape, permanent skeletal change

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7
Q

consideration XLA of carious 6s
take a radiograph - what information are you looking for to identify suitability of timing for these extractions

A

stage of eruption of 2nd molars, calcification of 7s bifurcation, degree of crowding, malocclusion type

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8
Q

if XLA of tooth 16, 36, and 46
what will you do with 26?

A

extraction

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9
Q

advantages of XLA of 1st permanent molars of poor prognosis at 9y/o

A

unerupted 2nd molar will mesially drift into contact with 2nd premolar [may not need ortho]
removal of pain
prevents spread of caries

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10
Q

disadvantages of XLA 1st permanent molars of poor prognosis at 9y/o

A

opposing arch can overerupt
GA may be required
difficult to chew without 7s through
disrupts eruption sequence
malocclusion
loss of permanent tooth
risk of GA
bad experience

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11
Q

what might a child require to get 3 permanent molars extracted

A

GA or sedation

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12
Q

8 y/o whos primary upper incisor become black and firm 3 years ago and fell out recently
he is missing 21
what is important about dental history to determine

A

was there trauma to the primary tooth

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13
Q

8 y/o whos primary upper incisor become black and firm 3 years ago and fell out recently
he is missing 21
what part of physical examination is important

A

if permanent central incisor is palpable

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14
Q

8 y/o whos primary upper incisor become black and firm 3 years ago and fell out recently
he is missing 21
given the history, give an account of events which most likely caused non-eruption of central incisor

A

trauma to the primary central incisor
this could have damaged the tooth germ, altered eruption path, disturbed dental follicles
ankylosis of the primary tooth caused displacement of tooth germ and dilaceration of the root

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15
Q

what are the principles of ortho management of non-eruption of upper central incisors

A

remove any primary and supernumeraries
ensure space for eruption
check contralateral
radiographs and monitor
refer
space maintainer URA if necessary

closed exposure - surgery to raise mucoperiosteal flap, orthodontic traction hook bonded to palatal surface, flap replaced with gold chain entering oral cavity through attached mucosa

open exposure - elliptical flap cut over crown, reserved for impactions which are soft tooth only and tooth crown is superificial

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16
Q

principles of orthodontics tx for unerupted permanent central incisor

A

restore stability, function, aesthetics
facilitate other forms of dentistry like crowns/bridges

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17
Q

what is the incisor relationship of a pt with proclined upper incisors and increased overjet

A

class II div 1

18
Q

methods to clinically assess a pt antero-posterior skeletal pattern

A

visual assessment of facial profile
palpatation of skeletal bases
ANB on cephalogram

19
Q

non-skeletal aetiological causes of class II div 1

A

digit sucking habit
tongue thrusting

20
Q

what type of orthodontic appliance can be used to harness growth potential for a patient with class II division 1

A

twin block therapy/appliance

promotes mandibular advancement, guides lower jaw forward when biting

21
Q

brief account of how it is though mandibular growth occurs

A

Development intramembranously but is proceeded by cartilaginous facial skeleton
Endochondral ossification, where cartilage becomes bone
Growth from condylar cartilage, downwards and forwards, surface resorption anteriorly and lingually with deposition laterally and posteriorly
Grows in width, length and height throughout puberty

22
Q

if class II div 1 has forward growth rotation, what would you expect to observe in the skeletal pattern

A

retruded maxilla
increased lower vertical height

23
Q

reasons for abnormalities in tooth number

A

hypodontia
retained primary teeth
supernumerary
early loss of primary teeth
unscheduled loss of permanent teeth

24
Q

ways to measure vertical skeletal relationship

A

FMPA
LAFH to TAFH [upper anterior facial height to lower anterior face height]

25
Q

definition of ARAB

A

active component = components applying force
retention = resistance to displacement forces [gravity, tongue, speech, mastication, AC]
anchorage = resistance to unwanted tooth movement
baseplate = selfcure PMMA [connector, retention, anchorage]

26
Q

what component would correct a posterior cross bite

A

mid palatal screw

27
Q

URA method of retention for permanent AND primary teeth

A

adams clasps
0.7mm HSSW permanent
0.6mm HSSW primary

28
Q

patient has an overbite
what URA modification can be used

A

flat anterior bite plane

29
Q

what modification to add to a URA to stop thumb sucking

A

rake or crib

30
Q

posterior bite plane
what is the purpose of this modification

A

fix anterior crossbite
expand upper arch

31
Q

anterior cross bite
construct URA

A

A = 12 z-spring, 0.5 HSSW
R = Adams 16/26, 14/24 0.7 HSSW
A = x
B = self cure PMMA, posterior bite plane

32
Q

posterior crossbite/expansion of upper arch
construct URA

A

A = midline palatal screw 0.5
R = Adams 4/4 6/6 0.7
A = reciprocal anchorage
B = self cure PMMA, PBP

33
Q

retract canines
construct URA

A

A = 3/3 palatal finger springs + guards 0.5
R = Adams 6/6 0.7, Southend 1/1 0.7
A = x
B = self cure PMMA

34
Q

retracting/moving canines palatally + reduce OB
construct URA

A

A = 3/3 buccal canine retractors 0.5 + LD tubing
R = Adams 6/6 0.7, Southend 1/1 0.7
A = x
B = self cure PMMA, FABP +3mm

35
Q

overjet 22, 21, 11, 12 + reduce overbite
construct URA

A

A = 22/1, 12/1 Roberts retractor 0.5 + tubing
23/13 mesial stops 0.7
R = Adams 6/6
A = x
B = self cure PMMA, FABP + 3mm

36
Q

fitting URA for the first time, what do you do

A
  1. ensure correct appliance for pt
  2. check appliance matches design
  3. inspect for sharp or traumatic areas
  4. check integrity of work
  5. in pt mouth, look for blanching or soft tissue damage
  6. check posterior retention, flyovers, then arrowhead engaging undercuts
  7. apply same principles in anterior retention
  8. activate appliance [1mm/month]
  9. demonstrate taking in/out and get pt to do it
  10. book review appt 4-6 weeks
37
Q

instructions to give to pt when giving a URA

A
  1. appliance will feel big and bulky
  2. may cause initial excessive salivation
  3. may impinge on speech for short period
  4. may cause initial discomfort and pain
  5. to be worn 24/7
  6. remove after every meal and clean with soft brush
  7. remove and store in protective container in contact sports
  8. avoid hard and sticky foods, cautious with hot food/drink
  9. missing appt and non compliance will lengthen tx time
  10. emergency contact details
38
Q

types of porosity which can be generated in production of URA or denture

A

contraction
gaseous
crazing
granularity

39
Q

name the surgery to repair cleft lip and palate

A

orthognathic surgery

40
Q
A