1B Flashcards
(126 cards)
1
Q
Transverse skeletal & dental problems:
● Skeletal ⇒
A
true facial asymmetry & maxillary constriction
2
Q
Transverse skeletal & dental problems:
● Dental ⇒
A
posterior crossbite
3
Q
○ —–population has posterior crossbite
A
5%
4
Q
True facial asymmetry ⇒ usually a
A
mandibular asymmetry (midface asymmetry rare)
5
Q
True facial asymmetry
● Causes:
A
○ Post trauma (condylar fx with scarring of soft tissues)
○ Growth deficiency/excess (of condyle)
6
Q
Apparent facial asymmetry ⇒ most common cause of
A
facial asymmetry
7
Q
Apparent facial asymmetry
A
● Mandibular shift (CR-CO shift)
● Dental interference uncomfortable, so pt shifts to crossbite
8
Q
Maxillary constriction treatment:
Adolescent
A
○ RPE or SPE (Jack screw type can do both)
9
Q
■ RPE =
A
1-2 quarter turns/day (quarter turn = 0.25 mm)
● Tx time 2-4 weeks
10
Q
■ SPE =
A
1 quarter turn every other day
● Tx time 4-8 weeks
11
Q
Max constriction treatment
adolescent
○ Retention for
A
3 months
12
Q
Max constriction treatment
● Adolescent:
○ Problemss:
A
■ Pain/soft tissue irritation; maxillary diastema; breakage/debonding
13
Q
Max constriction treatment
Preadolescent w/ 1° or mixed dentition:
A
○ Lingual arch type appliances (quad helix)
14
Q
Maxillary expansion summary:
● Relative light forces
A
○ Primary & mixed dentition
○ Lingual arch type (W-arch or Quad Helix)
○ Tx time months (usually 3 months) & retention for months
○ 50% dental & 50% skeletal change
15
Q
Maxillary expansion summary:
● Heavy forces (Rapid or slow)
A
○ Adolescent or adult
○ Jack-screw expansion device (or heavy spring)
○ Tx lasts days/weeks & retention done for months
○ 50% dental & 50% skeletal change
16
Q
Posterior dental crossbites etiology:
A
● Retained 1° teeth or crowding/tipped teeth (causes arch to be narrower)
17
Q
Types of Posterior Dental Crossbites
A
● Bilateral Maxillary Constriction
● Unilateral maxillary constriction
● Max. lingual dental displacement or Mand. facial dental displacement
18
Q
● Bilateral Maxillary Constriction -
A
symmetric maxillary arch
19
Q
Bilateral max constriction
○ When CO = CR, there is no shift
○ When CR does NOT equal CO ⇒ teeth DON’T
A
intercuspate comfortably, so CR-CO shift leads to facial asymmetry
20
Q
Bilateral max constriction
○ Tx ⇒
A
bilateral maxillary expansion for both
■ Doesn’t matter if CO = CR or not, as long as maxilla symmetric
21
Q
● Unilateral maxillary constriction
A
○ Asymmetric maxillary arch & CR = CO
○
22
Q
● Unilateral maxillary constriction
Tx ⇒
A
Asymmetric maxillary expansion
23
Q
● Max. lingual dental displacement or Mand. facial dental displacement
○ Tx ⇒
A
max & mand dental movement with cross elastics
24
Q
Dental Posterior Crossbite - posterior tooth position analysis
● Maxillary arch ideal alignment
A
○ central grooves should align & there is buccal offset of 2° 1rst molar
25
● Mandibular arch ideal alignment
○ Central grooves & buccal cusps should align
| ○ Offset of 1rst molar
26
Rationale for treating posterior dental crossbite - 90% success rate
● Improves
underlying premolar position (if moving 1° teeth)
27
Rationale for treating posterior dental crossbite - 90% success rate
● Increase
arch perimeter
28
Rationale for treating posterior dental crossbite - 90% success rate
● Reduce
abrasion (esp. In anteriors as pt moves from CR - CO
29
Rationale for treating posterior dental crossbite - 90% success rate
● Eliminates
CR-CO shifts (simplifies diagnosis & reduces potential for asymmetric growth)
30
Pediatric Posterior Crossbite Correction:
W arch or quad helix
31
Bilateral max constriction with CO-CR shift ⇒ Tx with
W-arch (pediatric0
32
● W-arch:
○ Reciprocal
anchorage
33
● W-arch:
| ○ W-configuration →
increases wire length ( ↑ flexibility)
34
● W-arch:
| ○ Force applied near
palatal CEJ (not thru Cres)
35
● W-arch:
| ■ Compression on
facial surfaces of molars
36
● W-arch:
| ■ 50%
skeletal & 50% dental
37
● W-arch:
| ○ Fabrication ⇒
1rst molars to place band
38
● W-arch:
| ○ Treatment ⇒
3-4 months
39
● W-arch:
| ■ Adjustments made every
4 weeks
40
● W-arch:
| ■ Goal to have teeth on
both sides overcorrected - should have overjet in max. arch
41
● W-arch:
| ○ Retention ⇒
~ 3 months (will relapse into normal occlusion)
42
Bilateral max constriction with finger habit ⇒ Tx with
Quad Helix
43
● Quad Helix
| ○ Reciprocal
anchorage
44
● Quad Helix
| ○ Quad wire
(increases length); wire 038SS (needs to provide orthopedic forces)
45
● Quad Helix○ Treatment duration & goal same as
W-arch
46
● Quad Helix
| ○ Only issue may be patient compliance →
pt may bend lingual wire
47
Cross-Elastics
| ● Treats
max. lingual & mand. facial displacement
48
Cross-Elastics
| ● Biomechanics ⇒
moves upper posteriors facially & lower posteriors lingually
49
Cross-Elastics
| ○ Reciprocal forces corrects
cross bite & extrudes tooth (may cause open bite)
50
Cross-Elastics
| ● Tx for
several weeks (if compliant)
51
Cross-Elastics
| ○ Worn all times, except
when eating
52
Cross-Elastics
| ○ No retention -
overcorrect & rebound should normalize occlusion
53
Anterior crossbite =
negative overjet (< 5% population)
54
● Only treat dental anterior crossbite
```
(Skeletal class I with class III molar + negative overjet)
○ If straight or concave profile as well → likely skeletal class III
```
55
```
Cephalometric analysis:
● Skeletal class III ⇒
```
SNA reduced; SNB increased; ANB reduced
56
```
● Dental anterior crossbite (class I skeletal)
○ 1 to FH (or SN) ⇒
```
retrusive
57
```
● Dental anterior crossbite (class I skeletal)
○ 1 to mandibular plane ⇒
```
protrusive
58
Dental anterior crossbite etiology:
● Tooth bud position; ectopic eruption; retained 1° teeth; supernumerary teeth
● Trauma, crowding
● Pseudo Class III
59
● Pseudo Class III
○ Class I, but interference causes CR-CO shift leading to anterior crossbite
60
Dental anterior crossbite treatment:
| ● Removable appliance ⇒
if only tipping movement needed
61
Dental anterior crossbite treatment:● Extraction ⇒
gives lingually erupting tooth space to erupt more facially
62
Dental anterior crossbite treatment:
○ Max. removable with double helical cantilever
■ Steel
round wire .022
63
Dental anterior crossbite treatment:
○ Max. removable with double helical cantilever
● Double helix →
increases length, thus ↑ range & springiness
64
Dental anterior crossbite treatment:
○ Max. removable with double helical cantilever
● If too small →
deformed by pt; if too big → heavy forces
65
Dental anterior crossbite treatment:
○ Max. removable with double helical cantilever
■ Biomechanics ⇒
Uncontrolled tipping force
66
Dental anterior crossbite treatment:
○ Max. removable with double helical cantilever
● Force applied
lingually
67
Dental anterior crossbite treatment:
○ Max. removable with double helical cantilever
● Retention via
adams clasps (Lots of retention required; many clasps)
68
vDental anterior crossbite treatment:
○ Max. removable with double helical cantilever
● Anchorage to teeth that are
clasped (No anchorage from palate)
69
Dental anterior crossbite treatment:
○ Max. removable with double helical cantilever
○ If anterior teeth were moving lingually, there would be anchorage on
palate (but NOT facially)
70
Dental anterior crossbite treatment:
○ Max. removable with double helical cantilever
● No labial bow → eating)
common feature of removables, but labial bow interferes with desired facial movement)
71
Dental anterior crossbite treatment:
○ Max. removable with double helical cantilever
■ Tx for
1-3 months
72
Dental anterior crossbite treatment:
○ Max. removable with double helical cantilever
● Activate 2 mm →
gives 1 mm of movement in 1 month
73
Dental anterior crossbite treatment:
○ Max. removable with double helical cantilever
● Retention for several months with
same appliance (not activated tho)
74
Dental anterior crossbite treatment:
○ Max. removable with double helical cantilever
■ Problems with device:
● Not activated appropriately
● Not enough retention in device
● Compliance (should be worn always except when
75
Dental anterior crossbite treatment:
○ Fixed appliance (with round wires → tipping & rotation)
■ NiTi ⇒
for initial movement
| ● Flexible with high range; Not formable
76
Dental anterior crossbite treatment:
○ Fixed appliance (with round wires → tipping & rotation)
● Round wire (rectangular wire would not provide any benefit)
○ Allows for
rotation & sliding along wire
| ○ For case example, some bodily movement to close diastema
77
Dental anterior crossbite treatment:
○ Fixed appliance (with round wires → tipping & rotation)
■ Biomechanics:
● Uncontrolled tipping
● Anchorage from adjacent teeth
● Retention via brackets/bands
● Ties with elastics or steel
78
Dental anterior crossbite treatment:
○ Fixed appliance (with round wires → tipping & rotation)
■ Adjustment:
● For NiTi wires →
adjustments every 6-8 weeks or longer (expect ~2 mm movement); then switch to steel wire for detailing
79
Dental anterior crossbite treatment:
○ Fixed appliance (with round wires → tipping & rotation)
■ Problems:
● Hygiene
80
○ Fixed appliance for AP bodily movement:
■ Rectangular wire
81
M-D bodily movement achieved with
round wire
82
Vertical skeletal problems ⇒
long face & short face
83
Vertical skeletal problems ⇒
| ● Long face with or without
anterior open bite
84
Vert skeletal problems
| ○ Variation in
lower face
| ● Short face (deep bite) - variation in lower face
85
Nhanes III:
| ● < 10% have deep bite
> 5mm
86
Nhanes III:
| ● < 5% have
anterior open bite
87
Ceph vertical proportions
```
● Mandibular plane angle
● % face height
○ ANS-Me / Na-Me
● Y-axis (growth direction)
○ Angle between FHP & Se-Gn
```
88
Dental open bites
| ● Simple open bites -
anterior teeth only
○ Normal transition from 1° to 2° dentition
○ Close prior to adolescence - no treatment required
89
● Complex open bites
○ Includes posteriors
○ Fails to close prior to adolescence
○ Sometimes ass. with skeletal problems
90
Dental open bite treatment:
● Erupt anteriors
○ Via
anterior elastics
91
Dental open bite treatment:
● Intrude posteriors
○
High pull headgear
92
Dental open bite treatment:
| ● Use facial proportions and lip to tooth information for
objective judgements
93
Dental deep bite treatment:
| ● Posterior eruption
○ Via anterior bite plane
94
Dental deep bite treatment:
| ● Level curve of spee
○ Reverse curve of spee with archwire - erupts middle segment
95
Dental deep bite treatment:
● Intrude anterior teeth
○ Via
upper intrusion arch (archwire from posteriors intrudes anteriors)
○ Via lower intrusion arch
96
Ankylosed 1° teeth
| ● 1° dentition with successors
○ Majority exfoliate on time & situation resolves
97
Ankylosed primary teeth
| ● 1° dentition w/o successors
○ Ankylosis worsens, so when extracted greater vertical defect (greater periodontal injury & attachment loss)
○ Consider early extraction
98
Basic infant reflexes ⇒
rooting, placing, sucking
99
Infantile swallow:
● Tongue to lower lip
| ● Jaws apart & lips together
100
Adult swallow
● Teeth together & lips relaxed
| ● Tongue to palate
101
Adult swallow appears
3-10 years
102
Nonnutritive sucking
● Normal childhood behavior (50-60% at age 1); relationship to breast/bottle feeding unclear
103
Nonnutritive sucking
● Spontaneously ends by
2-4 years (70-80% by 5 or 6)
104
Nonnutritive sucking
○ Persistent digit habits more common in
females
105
Nonnutritive sucking
| ● Dental effects based on
equilibrium theory
106
Nonnutritive sucking
| ○ Equilibrium theory ⇒
Light continuous forces move teeth & elimination of light continuous forces move teeth (go back to original position)
107
Nonnutritive sucking
| ● Ideally, intervention precedes
permanent dentition
| ○ Anterior open bite with 1° dentition will close when 2° dentition erupts (if habit stopped)
108
Thumb sucking →
uppers proclined & lowers retroclined ( ↑ overjet); possible intrusion
109
Thumb sucking →
● Asymmetric or symmetric open bite
● Maxillary constriction
● Sucked finger usually clean
110
Nonnutritive sucking
| Treatment:
```
● Counseling (if near adolescence)
● Rewards
● Reminders
● Adjunctive therapy:
○ Fixed appliance ⇒ reminder/obstruction
```
111
Nonnutritive sucking
| ● Adjunctive therapy:
○ Elastic bandage ⇒ around elbow; only at night
■ Bulkiness reminds child; not a tight restraint
■ For 6-8 weeks
112
Nonnutritive sucking
| ○ Fixed appliance ⇒
reminder/obstruction
113
Nonnutritive sucking
Fixed appliance
■ Band
6’s or E’s (reduces length of moment arm, thus less flexible)
114
Nonnutritive sucking
Fixed appliance
■ Consider
quad helix is posterior crossbite present
115
Nonnutritive sucking
Fixed appliance
● Anterior helixes would disrupt
habit
116
Nonnutritive sucking
Fixed appliance
■ Maintained 6 months following
termination of habit (prevents relapse)
117
Nonnutritive sucking
Fixed appliance
● Few
replacement habits; not often
118
Pacifiers:
● All designs comparable & produce dental changes if used long enough
119
Pacifiers
| ● Dental effects:
○ Symmetric open bite
| ○ Maxillary constriction
120
Post-habit spontaneous dental changes
● When habit stopped, dental changes reverse
121
● Traumatic intrusion:
| ○ May lead to
pulpal necrosis
122
● Traumatic intrusion:
○ Orthodontic extrusion can allow for
endodontic access
123
● Traumatic intrusion:
○ Surgical intervention for
intrusion > 6 mm
124
● Don’t treat deep bite in
mixed dentition → unless soft tissue trauma
125
Treatment options for ankylosed 2nd 1° molars without successors:
● Maintain 1° molars (if no bony defects)
● Extraction before vertical discrepancy too great
● Decoronation - remove crown & leave root tip (facilitates vertical bone growth)
126
Spontaneous correction of ectopic eruption depends on
how far ectopic & angle
