Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Ortho > class 2 div 1 malocclusion > Flashcards

class 2 div 1 malocclusion Flashcards

1
Q

definition

A

lower incisor edges lie posterior to the cingulum plateau of the upper incisors
increased OJ
U central incisors proclined or of average inclination

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

incidence

A

15-20% (most common malocclusion)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

why treat?

A

aesthetics
dental health

  • prominent incisors at risk of trauma esp if incompetent lips
  • OJ >9mm x2 as likely to suffer trauma - IOTN 5a
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

broad categories of aetiology/features

A

skeletal pattern
STs
dental factors
habits

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

AP skeletal pattern

A

usually associated with a class 2 skeletal pattern
commonly due to a retrognathic mandible
- maxillary protrusion less common
do see with skeletal class 1
v rarely see with skeletal class 3 but possible - could be purely due to STs e.g. lip trap

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

skeletal pattern - vertical

A

found in association with a range of vertical skeletal patterns
decreased vertical = increased OB
increased vertical = decreased OB/AOB

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

skeletal pattern - transverse

A

no particular association with transverse problems

could have buccal segment CB due to maxillary contraction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what is incompetent lips

A

don’t sit together at rest without muscular activity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what are incompetent lips often due to?

A

prominence of incisors and/or underlying skeletal pattern

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what ST factor can be an etiological factor in increased OJ?

A

L lip trap

  • proclination Us
  • retroclination Ls
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what is the consequence of incompetent lips when swallowing?

A

special effort is needed to achieve an anterior oral seal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

methods of achieving an anterior oral seal

A

1 - lip to lip seal by activity of circum-oral musculature
2 - mandible postured forward to allow lips to meet
3 - L lip drawn up behind U incisors,
4 - tongue placed forwards between incisors to meet L lip - tends to contribute to increased OB
5 - combination of these

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

dental factors

A
  • increased OJ (incisors proclined or average?)
  • common to have spaced U anteriors if proclined
  • molars usually class 2 but crowding could alter this
  • habitually parted lips
    /
  • OB varies
  • can see good alignment, crowding or spacing
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

consequences of habitually parted lips

A

drying of gingiva and exacerbation of any pre-existing gingivitis
rolled gingival margins- inflamed
U lip not covering U gingival margin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

non-nutritive sucking habits

A 
thumb
fingers
blanket
lip
combination
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what does the effects of a sucking habit depend on?

A
  • duration and intensity
  • if >6hrs per day will have occlusal effects*
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

occlusal features of a sucking habit

A

proclination of U incisors
retroclination of L incisors
localised AOB or incomplete OB
narrow upper arch (may see unilateral posterior CB)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

why does a sucking habit result in a narrow upper arch?

A
  • tongue in low position due to thumb - (tongue help shapign upper arch width)
  • maxilla constricts due to action of buccinator
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

habit treatment principles

A

stop before age 9
allow spontaneous improvement - <9yrs would hope for improvement
tx residual malocclusion if required

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

methods of stopping sucking habit

A
  • positive reinforcement
  • bitter nail varnish
  • gloves
  • removable appliance habit breaker (good for pt who wants to help themselves)
  • fixed appliance habit breaker (palatal arch with goalposts at front - stops thumb going into mouth)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

management options

A
  1. accept
  2. attempt growth modification
  3. simple tipping of teeth (URA)
  4. camouflage
  5. orthognathic surgery
22
Q

indications to accept

A
  • mildly increased OJ
  • significant OJ but not unhappy and not keen on tx
23
Q

discussion to have with pt/parent re accept

A
  • will any tx options be more difficult in future?
  • risk of trauma
  • advice re mouthguard for contact sports
24
Q

what is growth modification and when can it be done?

A

you apply significant force to the skeletal bases to try and improve the underlying skeletal discrepancy
while still growing

  • girl 12 +/- 2
  • boy 14 +/- 2
25
how does headgear and EO traction work
- try and restrain growth of the maxilla horizontally and/or vertically - use cranium as anchor, bands attach to URA - up and backward pull for upper dentition - distalise U molar, retract UI spring loaded and facebow (**500g force**)
26
why do you need extremely good pt cooperation for headgear?
wear at least 14 hours per day
27
how does a functional appliance work?
"utilise, eliminate or guide the forces of muscle function, tooth eruption and growth to correct a malocclusion"
28
what malocclusion is functional appliances mostly used for?
class 2 div 1
29
what other malocclusions can fct appliances be used for?
``` class 2 div 2 class 3 (but limited use) ```
30
describe the growth modification effect of fct appliances
- mandible postured down and forwards - aim to restrain max growth and encourgae mand growth
31
therapeutic effect of fx app.
- mostly **dento-alveolar changes** - distal movement of upper dentition - mesial movement of lower dentition - retrocclination of UI - proclination of LI - minor degree of **skeletal changes** - RCT's indicate that degree of max restraint and mand growth is usually small (**1-2mm**) - significant variation in response - skeletal 27%, dental 73%
32
how should the registration for a functional appliance be taken?
with the teeth as close to edge to edge as possible
33
2 main types of fct appliance
removable or fixed
34
removable fct appliance
``` tooth-borne - twin block (most common) - activator/bionator soft-tissue borne - Frankel II - buccal shields and wire frame which fits around teeth without clasping onto teeth ```
35
fixed functional appliance
Herbst - capping bonded onto surface of teeth, **connecting rod** between upper and lower which postures mandible forward
36
twin block design
**midline palatal screw** to allow expansion - usually needed to keep pace with lower arch **labial bow**- if proclination and spacing speech often an issue - persistence get lat open bite - resolves in a few months e.g. just wear block at night
37
what is the success of a twin block dependent on?
favourable growth and enthusiastic patient
38
why should a fct appliance be used during growth?
teeth move more easily more compliant can harness effect of favourable growth if they have it
39
two options for timing of a fct appliance
early use about 10yo (**2 phase tx**) - have to withdraw tx for transition from mixed to permanent (2yrs) - then use fixed for fine realignment later use - 12-14 yo late mixed or early permanent dentition (**1 phase tx**)
40
disadvantages of early fct appliance tx
* early skeletal effects from fct appliance or headgear therapy not maintained in long term * overall tx time increased, 2 phase tx * early fct appliance plus retention * fixed app in early permanent dentition * research shows **little if any difference** in results between those treated early and those who waited until permanent dentition
41
advantages of early fct appliance tx
improve appearance earlier (teasing and potential psychological benefit) reduce risk of trauma often better compliance with appliance wear
42
when are the only times URAs (simple tipping) would really be used?
v mild class 2 or class 1 OJ due to proclined and spaced incisors OB favourable and then only after a specialist assessment
43
URA design to retrocline anterior teeth
active component - Roberts retractor, 0.5mm HSSW in tubing retention - Adams clasps 0.7mm HSSW anchorage - stops mesial to 3s (have already been retracted) baseplate - FABP
44
when is camouflage useful?
- if haven't worn fct well enough/are too old for a fct - malocclusion is not severe - main concern is position of teeth
45
what does camouflage usually involve?
fixed appliances | if goal is to reduce the OJ may need U arch extractions to give space (or distal movement)
46
txing an increased OJ and class 2 molars - camouflage
* ext method - ext U 4s, bring anteriors back ( with unfavourbale molar forward movement) * non-ext method - distalise molars to class 1 (aided by ext of U7s - but would want 8 in good position to come down and replace 7 when tx completed)
47
when would orthognathic surgery be indicated?
growth complete and profile concerns - F 18-19 yrs - M 20-21 yrs severe skeletal discrepancy in AP and/or vertical direction
48
what does orthognathic surgery usually involve?
mandibular surgery but may also involve maxillary surgery - maxillary impaction - mandibular advancement e.g. bilateral sagittal split osteotomy
49
what appliance is usually required as well as orthognathic surgery?
fixed - before , during and after | rectangular SS arch wires with printable hooks - run elastics to fine tune occlusion and keep teeth in correct place
50
class 2 elastic
correct a class 2 occlusion
51
class 3 elastic
correct a class 3 occlusion

Ortho (22 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions