Orthodontics Flashcards
1
Q
Constituents of Stainless Steel (4)
A
- Primary iron
- Second most is chromium
- Nickel
- Titanium
2
Q
Advantages of URAs (6)
A
- Excellent anchorage
- Cheaper than fixed
- Less chair side time
- OH easier to maintain
- Non destructive to tooth surface
- Can easily reduce overbite
3
Q
Disadvantages of URAs (6)
A
- Less precise control of movement
- Teeth cannot be intruded or extruded
- Can be easily removed
- Only 1-2 teeth can be moved at a time
- Specialist technical staff required
- Rotations very difficult to correct
4
Q
ARAB
A
Active Components
Retentive
Anchorage
Baseplate
5
Q
HSSW
A
Hard Stainless Steel Wire
6
Q
FABP
A
Flat Anterior Bite Plane
7
Q
URAs - How many teeth can be moved at a time
A
1-2 teeth at a time
1mm per month
8
Q
Increasing thickness of wire
A
Increasing force applied to teeth
9
Q
Types of clasp for URAs (3)
A
Adams clasp
Southend clasp
Labial bow
10
Q
URAs - Thickness of wire for retentive components
A
0.7mm permanent
0.6mm deciduous
11
Q
URAs - Thickness of wire for active components
A
0.5mm
12
Q
Types of active components for URAs (5)
A
- Finger Spring
- Z Spring
- T Spring
- Flapper Spring
- Buccal Canine Retractor
13
Q
Components of a Finger Spring and what they do (4)
A
Tag (attaches to acrylic)
Coil (Where force comes from)
Guard (Allows active arm to slide along it)
Arm
14
Q
What is a Z Spring used for? (3)
A
Used to push teeth forward
Can be used for small amounts of rotation
Uncoiled to activate it
15
Q
What is the function of a buccal canine retractor
A
Moves teeth back into the line of arch
16
Q
What can be done for Class III patients (interceptive orthodontics)
A
If the patient can achieve edge to edge bite on incisors, camouflage/URA is possible
If not, refer patients before they reach the age of 10
17
Q
Why are posterior cross bites overcorrected
A
As 50% of them relapse
18
Q
What age should orthodontic assessment be carried out? (2)
A
Brief - Age 9
Comprehensive - 11/12
19
Q
Contraindications to orthodontic treatment (4)
A
- Allergy to nickel or latex
- Epilepsy/drugs
- Drugs
- Imaging
20
Q
Skeletal Base Class I
A
Maxilla 2-3mm in front of mandible
21
Q
Skeletal Base Class II
A
Maxilla more than 3mm in front of mandible
22
Q
Skeletal Base Class III
A
Mandible in front of maxilla
23
Q
FMPA
A
Frankfort Mandibular Planes Angle
24
Q
Incompetent lips
A
Lips that do not meet at rest
25
Lip Trap (2)
1. May procline upper incisors
2. Can lead to relapse of overate if persists at end of treatment
26
Occlusal features of a digit sucking habit (4)
1. Proclination of UI
2. Retroclination of LI
3. Localised AOB or incomplete OB
4. Narrow upper arch +/- unilateral posterior cross bite
27
Class II Division 1 (3)
1. The lower incisor edges lie posterior to the cingulum plateau of the upper incisors
2. Upper incisors are proclined or of average inclination
3. Usually increased OJ
28
Class II Division 2 (3)
1. LI occludes posterior to the cingulum plateau of UI
2. Upper incisors retroclined
3. OJ is reduced but can also be increased
29
Average overbite
Upper incisors cover 1/2 to 1/3 of lower incisors crowns
30
Radiographs helpful in orthodontic assessment (3)
1. OPT
2. Maxillary anterior occlusal
3. Lateral cepahlogram
31
Special investigations for orthodontic assessment (4)
1. Radiographs
2. Study models
3. Clinical images
4. Vitality tests
32
Planes for skeletal pattern assessment (3)
1. Antero-posterior
2. Vertical
3. Transverse
33
Methods for assessing skeletal pattern (3)
1. Visual assessment
2. Palpate skeletal bases
3. Lateral cephalometry
34
Class II FMPA
Reduced
35
Class III FMPA
Increased
36
LAFH (2)
Lower Anterior Face Height
From menton to subnasale
37
UAFH (2)
Upper Anterior Face Height
Glabella/Nasion (eyebrows) to subnasale
38
Mild crowding
<4mm
39
Moderate crowding
4-8mm
40
Severe crowding
>8mm
41
Assessment methods for crowding (3)
1. Space available - space required
2. Overlap technique
3. Mixed dentition analysis
42
Aims of orthodontic treatment (3)
1. Good aesthetics
2. Functional
3. Stable occlusion
43
Uses of study casts (7)
1. Record keeping
2. Track progress
3. Insight when patient isn't there
4. Design appliances
5. More info - better informed decisions
6. Teaching purposes
7. Retrospective studies
44
Anchorage Definition
Resistance to unwanted tooth movement and displacement forces
45
Displacement Forces (5)
1. Tongue
2. Mastication
3. Speech
4. Gravity
5. Active component
46
Size of FABP
Overjet + 3mm
47
What is the baseplate for URAs made of
Self cure PMMA
48
Fitting the URA - DASIIPAADS
Details match
Appliance matches
Sharp edges
Integrity of wirework (work hardening)
Insert appliance
Posterior retention
Anterior retention
Activate appliance
Demonstrate insertion and removal to pt.
See pt every 4-6 weeks
49
Pt information for URA - BESWIRRAME
Big and bulky
Excess salivation
Speech may be difficult at first
Worn 24/7
Initial discomfort
Remove after meals and clean
Remove before contact sport
Avoid hard/sticky foods
Missing appointments
Emergency details
50
What machine is needed for lateral cephalometry
Cephalostat
51
What type of collimation is used in a cephalostat
Triangular
52
SNA Avg
81 +/- 3
53
SNB Avg
78 +/- 3
54
ANB Avg
3 +/- 2
55
Angles in Class II (3)
1. SNA avg
2. ANB usually increased
3. ANB > 5
56
Concave profile
Class III
57
Convex profile
Class II
58
Angles in Class III (3)
1. SNA decreased if maxilla deficient
2. SNB often avg but may be increased if mandible prognathic
3. ANB < 1
59
FMPA - Where do planes meet
External occipital protuberance
60
Frankfurt Plane
Orbitale to porion
61
Mandibular plane
Menton to gonion
62
FMPA Avg
27 +/- 4
63
Aetiology of Malocclusion (4)
1. Skeletal
2. Dental
3. Soft tissue
4. Environmental/Habits
64
Local causes of malocclusion (5)
1. Variation in tooth number
2. Variation in tooth size/form
3. Variation in tooth position
4. Soft tissue abnormalities
5. Local pathology
65
Supernumerary types (4)
1. Conical
2. Tuberculate
3. Supplemental
4. Odontome
66
Variation in tooth number (5)
1. Supernumerary
2. Hypodontia
3. Retained primary
4. Early loss of primary
5. Unscheduled loss of permanent
67
Why might primary teeth be retained? (5)
1. Absent successor
2. Ectopic successor or dilacerated
3. Infra-occluded/ankylosed
4. Delayed development
5. Pathology
68
Why might children lose primary teeth early? (4)
1. Trauma
2. Periapical pathology
3. Caries
4. Resorption by successor
69
Variation in tooth size/form (3)
1. Macrodontia
2. Microdontia
3. Abnormal form
70
Abnormalities of tooth position (2)
1. Ectopic teeth
2. Transpositions
71
Ectopic canines management options (6)
1. Prevention
2. Interceptive - extract cs
3. Accept - Retain 3 and observe
4. Surgical exposure and orthodontic alignment
5. Surgical extraction
6. Autotransplantation
72
Ectopic canines prevention
Monitor from age 9 onwards
73
Transposition definition
Interchange in the position of two teeth
74
Classification of transposition (2)
True
Pseudo
75
Most common transpositions (2)
Upper canine and first premolar
Lower canine and incisor
76
Abnormalities of soft tissue for orthodontics (3)
1. Digit sucking
2. Frenum
3. Tongue thrust
77
Large labial frenum
May cause median diastema
78
Pathology which may cause malocclusion (3)
1. Caries
2. Cysts
3. Tumours
79
How long should FABP be used for (3)
1. Continued after canines retracted
2. Active components will move teeth faster than teeth can continue to erupt
3. New bone is spongy - pressure from posteriors puts pressure on this
80
Why does FABP need to be trimmed
To allow space for UI to be retracted
81
Roberts Retractor (4)
1. Looks like buccal canine retractor but joined in the middle
2. Brings anterior teeth back
3. Need medial stops on mesial aspect of canines
4. 0.7mm HSSW + 0.5mm ID tubing
82
Which active components need ID tubing
Buccal canine retractor
Roberts retractor
83
What are stops made of for URAs
0.7mm HSSW flattened
84
Active component for expanding the palatal screw (2)
Midline palatal screw
Need posterior bite plane which includes all posterior teeth
85
Midline palatal screw (3)
1. Screw turned once a week
2. 0.25mm per turn
3. Pt instructions very important
86
Name of plyers (2)
Adams 64
Adams 65 coil formers
87
MOCDO
Missing Teeth
Overjet
Crossbite
Displacement on contact points
Open bite/Overbite
88
When using IOTN on study casts - overjets
Always assume lips incompetent
89
When using IOTN on study casts - crossbites
Assume a discrepancy between RCP and ICP of > 2mm is present and award grade 4c
90
When using IOTN on study casts - reverse overjet
Assume masticatory and speech components
91
Correct time for deciduous teeth to be extracted to encourage permanent to erupt
One half to two thirds root development of permanent
92
Functional appliances (3)
1. Very good for Class II Div 1
2. Mandible postured forward away from its normal rest position
3. Condyle encouraged to grow
93
How much of functional appliance change is dentoalveolar and how much is skeletal
Skeletal 30%
Dentoalveolar 70%
94
Tipping force
35-60g
95
Bodily movement force
150-200g
96
Intrusion force
10-20g
97
Extrusion force
35-60g
98
Rotation force
35-60g
99
Torque force
50-100g
100
Light Force (5)
1. Resorption of lamina dura on pressure side
2. Apposition on osteoid on tension side
3. Remodelling of socket
4. PDL fibres reorganise
5. Gingival fibres don't reorganise but become distorted
101
Moderate Force (3)
1. Cell free areas on pressure side (hylinisation)
2. Period of stasis
3. Undermining resorption
102
Undermining resorption
Nothing happens for a while and then clunk due to undermining resorption
103
Excessive force (3)
1. Necrosis
2. Undermining resorption
3. Resorption of root surfaces
104
Factors affecting response to orthodontic force (4)
1. Magnitude
2. Duration
3. Age
4. Anatomy
105
Interceptive orthodontics definition
Any procedure that will reduce or eliminate the severity of a developing malocclusion
106
< 3mm space in deciduous dentition
50% crowding
107
3-6mm space in deciduous dentition
20% crowding
108
> 6mm space in deciduous dentition
No crowding
109
No spacing in deciduous dentition
66% crowding
110
When do 6s erupt
Age 6
111
When do 1s erupt
Age 7
112
When do 2s erupt
Age 8
113
When do 4s erupt
Age 10
114
When do 3s and 5s erupt
11-12
115
When do 7s erupt
12-13
116
Growth modification methods (2)
1. Functional appliances
2. Headgear
117
Aims of orthodontic treatment
To produce an occlusion which is stable, functional, aesthetic
118
Comprehensive orthodontic treatment
Full correction of malocclusion
119
Compromise orthodontic treatment
Correct certain aspects and accept others
120
Stages of ortho treatment planning (4)
1. Plan around LLS
2. Decide on tx in lower
3. Build upper arch around lower aim for Class I incisor and canine relationship
4. Decide if molars will be Class I or full unit Class II
121
Why is an overjet of > 9mm such an issue
Twice as likely to suffer trauma
122
Most common reason for class II skeletal pattern
Retrognathic mandible
123
NNSH
Non nutritive sucking habits
124
Habit treatment principles (3)
1. Stop habit
2. Allow spontaneous improvement
3. Treat residual malocclusion if required
125
Class II Div 1 management options (5)
1. Accept
2. Attempt growth modification
3. Simple tipping of teeth
4. Camouflage
5. Orthognathic surgery
126
Functional appliance definition
Functional appliances utilise, eliminate or guide the forces of muscle function, tooth eruption and growth to correct a malocclusion
127
Which way does the upper arch move with functional appliances
Distally
128
Types of removable functional appliance (3)
Tooth borne
- Twin block
- Activator/bionator
Soft tissue borne
- Frankel (FR II)
129
Type of fixed functional appliances
Herbst
Difficult to fix if they break
130
When should a functional appliance be used (3)
1. During growth
2. Ideally 11-14
3. Motivation best way to assess, rather than growth assessment
131
Disadvantages of early functional appliance use (3)
1. Effects not maintained in long term
2. Overall tx time increased
3. Little evidence to support any difference in results with early/normal tx
132
Benefits of early functional appliance tx (3)
1. Improve appearance earlier (psychological)
2. Reduce trauma risk
3. Better compliance
133
Class II Div 2 Soft tissue patterns (3)
1. High resting lower lip line
2. Marked labio mental fold
3. High masseteric forces
134
Pattern for laterals in Class II div 2 (3)
Upper 2s often trap lower lip
Proclined and often mesio-labially rotated
Poor cingulum
135
IIA
Inter incisal angle
136
IIA Avg
135
137
Effect of Class II Div 2 on gingiva
Gingival stripping if teeth occlude onto gingivae
138
IIA of Class II Div 2
Increased
139
Management of Class II Div 2 (4)
1. Accept
2. Growth modification
3. Camouflage
4. Orthognathic treatment
140
Modified twin block design
Quick alignment of teeth so pt motivation drops quickly
141
Methods of proclining upper incisors (3)
1. Modified twin block
2. Springs or screw
3. Upper sectional fixed appliance
142
Camouflage treatment
Accept underlying skeletal base and aim for Class I incisor relationship
143
How is IIA corrected (2)
Palatal root torque UI
Proclination of LI
144
Upper incisor torquing (2)
1. Need adequate cancellous bone palatal to UI
2. Risk of root resorption
145
When is a deep overbite best corrected
When the patient is still growing
146
What incisor relationship tends to be more affected by dental anomalies
Class II Div 2
Hypodontia
147
Opposite of hypodontia
Hyperdontia
148
Supplemental teeth definition
Supernumerary with the same morphology as a normal tooth
149
Supernumerary distal to the dentition
Distodens
150
Rarest tooth for hypodontia
Canines
151
What tooth shape abnormality is more common in hypodontia patients
Peg laterals
152
Upside down tooth
Inverted
153
What is a transpalatal arch used for (3)
1. Anchorage
2. Rotation
3. Limited widening or contraction
154
What is a palatal arch with a nance button used for
Anchorage
155
What is a quad helix used for (6)
1. Bilateral expansion
2. Fan style expansion
3. Rotation of molars
4. Expansion in cleft palate
5. Can be modified to procline incisors
6. Assist in habit breakers
156
What wire is used for palatal arches
0.9mm HSSW
157
Fixed orthodontics advantages (7)
1. 3D tooth movement
2. Can be used in both lower and upper
3. Individual forces on each tooth
4. Not easily removed by pt
5. Works 24/7
6. Less invasive of tongue space
7. Minimal palatal coverage
158
Fixed orthodontics disadvantages (9)
1. Root resorption risk
2. Decalcification
3. Visual appearance
4. Soft tissue trauma
5. Cost
6. OH - motivation
7. Poor anchorage
8. Destructive - etching
9. Highly specialised
159
Why can't 6's be moved backwards with a palatal arch with a nance button
Molars will rotate and cause extra force on the button which can cause resorption on the palate
160
Is the trans palatal arch an active component
No - anchorage
161
Why is unilateral expansion with a quad helix difficult
Newtons law - equal and opposite forces
162
How can unilateral expansion with a quad helix be made easier
Make the arm on one side larger and on the other side shorter
163
Where might fan type expansion be used
Cleft patients who have narrow palates
Scar tissue cannot grow like normal tissue
164
What are arch wires made of for fixed orthodontics
Nickel Titanium
165
What property of arch wire makes the teeth move
Shape memory
166
What are stops made of in URAs
0.7mm flattened HSSW
167
What do you need to do to a FABP as anteriors move
Cut it so the anteriors have space to move back
168
Why shouldn't posterior bite planes be used for patients with overjets
They will relapse
When URA is removed, force is on anteriors
169
Purpose of GIC around bands on 6s (2)
1. Fixes band to tooth
2. Seals gap between band and tooth
170
How long do orthodontic spacers take to work
Very quick
Can get patient back the same day
171
Types of retainer (3)
1. Thermoplastic
2. Holly/conventional
3. Bonded
172
If bands on 6s fall of what should be done? (3)
Alginate impression with bands in situ
Orthodontic spacers back in
Pt back in a week
173
Benefits of orthodontics (3)
1. Appearance
2. Function
3. Dental health
174
How likely is orthodontics to impact speech
Rarely impacts speech
175
IOTN 1-2
No/Low need for treatment
176
IOTN 3
Borderline need for treatment
177
IOTN 4-5
High need for treatment
178
Risks of remaining impacted teeth (3)
1. Rooth resorption
2. Delayed eruption
3. Cyst formation
179
Risks associated with significant displacement - crossbites (3)
1. Loss of periodontal support
2. Tooth wear
3. Asymmetry
180
Risk associated with overbites (3)
1. Only an issue if traumatic
2. Gingival stripping
3. Loss of perio support
181
With what orthodontic malocclusions is there a weak connection with TMD (4)
1. Crossbite with displacement
2. Class II with retrusive mandible
3. Class III
4. AOB
182
Orthodontics for TMD
No guarantee TMD will improve
183
Main risks of orthodontics (4)
1. Decalcification
2. Root resorption
3. Relapse
4. Soft tissue trauma
184
Other risks of orthodontic treatment (7)
1. Recession
2. Loss of periodontal support
3. Headgear injuries
4. Enamel fracture and toothwear
5. Loss of vitality
6. Allergy
7. Poor/failed treatment
185
Patients at higher risk of decalcification (3)
1. Caries history
2. Pre existing decalcification
3. Erosion
186
Average root resorption
1mm over 2 years fixed appliances
187
How common is severe root resorption due to ortho
1-5%
188
Risk factors for root resorption due to ortho (4)
1. Type of tooth movement (intrusion, torque)
2. Root form (blunt, pipette, resorbed already)
3. Previous trauma
4. Nail biting
189
Relapse definition
The return of features of the original malocclusion following correction
190
Features more prone to relapse (6)
1. LI crowding
2. Rotations
3. Instancing 2s
4. Spaces & diastemas
5. Class II Div 2
6. AOBs
191
How to avoid recession from ortho
Keep teeth within alveolar bone
192
Periodontal health and ortho (2)
Periodontitis must be treated, stabilised and maintained before ortho starts
Treated as priority over ortho
193
Prevention of headgear trauma
Minimum 2 safety mechanisms
194
Safety mechanisms on headgear (3)
1. Snap away traction spring
2. Nitom facebow
3. Masel strap
195
Toothwear due to ortho (2)
1. Greater risk with ceramic brackets
2. Enamel fracture during debond
196
Risk of loss of vitality due to ortho (3)
1. Rare
2. More risk if previous trauma or compromised tooth
3. Warn patient
197
Ortho allergies (3)
1. Nickel
2. Latex
3. Colophony (adhesive)
198
Risk of poor/failed treatment - ortho (6)
1. Poor diagnosis
2. Poor tx planning
3. Technique error
4. Poor cooperation
5. Repeated breakages
6. Attendance
199
Risks vs benefits of ortho (3)
Benefits more apparent at end of tx
Risks throughout tx
Benefits must outweigh risks
200
What must you do if an orthodontic component has broken off (2)
Account for the missing piece
If unaccounted for send pt to A&E
201
When can silver soulder be used to fix URAs (3)
1. When its not too close to gingivae
2. When its far enough away from the acrylic
3. Not an area of flex
202
Broken southend clasp
Turn them into C clasps
203
Debonded retainer (4)
1. Remove composite
2. Ensure wire passive
3. Bond back composite
4. OHI
204
Debonded bracket
Remove bracket and return to orthodontist
205
Debonded wire on square arch wire (3)
1. Make sure ligature is firmly attached
2. Get pt to slide to side to clean
3. Return to ortho
206
Broken Adams clasp (5)
1. Account for missing piece (A&E)
2. Grind down edges
3. Check retention
4. If unretentive get component replaced
5. Need working model, appliance and prescription
207
Archwire slippage (4)
1. Cut end of archwire
2. Hold it as you cut it
3. Bend back on itself
4. Return to orthodontist
208
Debonded retainer with now active wire (3)
1. Cute wire off and smooth
2. Explain to pt what you've done
3. Give pt options (nothing, get new one)
209
Multiple teeth debonded from bonded retainer (4)
1. Remove whole retainer
2. Check health of teeth
3. Give pt options (thermoplastic/bonded)
4. If pt wants nothing get them to sign something with risks on it
210
Broken transpalatal arch (2)
1. Floss in loop and get pt to hole
2. Cut off wire high speed
211
Band debonded (4)
1. Cut wire distal to 5
2. Bend wire back on itself
3. OHI
4. Return to ortho
212
Adams clasp fractured at arrowhead (4)
1. Can soulder
2. OR squeeze arrowhead together
3. OR cut whole thing off
4. Check retention
213
Smashed baseplate (2)
Offer thermoplastic retainer
Return to ortho
214
Lots of brackets debonded (5)
1. Normally trauma
2. Trauma stamp
3. Remove arch wire
4. Cut wire distally
5. Splint any mobile teeth
215
Which gender is cleft palate more common in
Females
216
Which gender is cleft lip and palate more common in
Males
217
LAHSHAL classification (2)
Assigns a letter to every part which has a cleft
Lowercase for partial cleft
218
Left side cleft lip and palate
SHAL
219
Right side cleft lip and palate
LAHS
220
Environmental aetiology of CLP (5)
1. Social deprivation
2. Smoking
3. Alcohol
4. Anti-epileptics
5. Multivitamins
221
Genetic aetiology of CLP (5)
1. Syndromes
2. Family history
3. Sex
4. Laterality
5. Ethnicity
222
How did the smoking ban alter CP and CLP
CP reduced by 10%
CLP unchanged
223
What other major organ is more likely to have anomalies in CLP patients
Heart
224
Timeframe for lip closure in CLP after birth
3 months
225
Timeframe for palate closure in CLP after birth
6-12 months
226
CLP speech impacts (3)
1. Soft palate doesn't work as well - plosive sounds impacted
2. Hypernasal - more air through nose
3. Speech specialist every 6 months
227
Why is hypodontia more likely in CLP pts
Dental lamina impacted when cleft goes through alveolus
228
Timeframe for alveolar bone graft in CLP patients
8-10 years
229
Timeframe for definitive orthodontics for CLP
12-15 years
230
Timeframe for surgery for CLP
18-20 years
231
Dental impacts of CLP (5)
1. Hypodontia
2. Impacted teeth
3. Crowding
4. Growth
5. Caries
232
What information should be included when consenting a pt with perio for orthodontics
Appearance of black triangles - not all space will disappear
233
Overbite reduction in adults
Tooth intrusion more difficult than continuation of molars to erupt
234
What type of brackets should not be used on lowers
Ceramic
235
Ortho - Differences treating adults compared to children (5)
1. Lack of growth
2. Periodontal disease
3. Missing/heavily restored dentition
4. Physiological factors
5. Adult motivation
236
Can mid palatal screws be used in adults
No the mid palatal suture has been closed
Can only expand with surgery
237
Loss of perio support impacts on ortho (2)
1. Tooth centre of rotation moves apically
2. Anchorage value reducing
238
Physiological factors impacting adult ortho (3)
1. Decreased cell turnover
2. Initial movement can be slower
3. Use lighter forces
239
Ortho as an adjunct to restorative (3)
1. Intrusion of over erupted teeth
2. Upright abutments to aid restoration
3. Extrusion to increase crown length
240
Team involved in planning orthognathic surgery (4)
1. Orthodontist
2. Maxfax surgeon
3. Clinical psychologist
4. Technologist
241
Ideal tx goals of orthodontics (6)
1. Tight contacts with no rotations
2. Class I incisors
3. Class I molars
4. Flat occlusal plane or slight curve of spee
5. Long axis of teeth have slight medial inclination except LI
6. Crowns of canines and posterior have a lingual inclination
242
Andrews six keys
Ideal goals of orthodontic tx
243
Wire used for fixed applianced
Nickel titanium
244
Which type of wire has lower friction and slides easier
Stainless Steel
245
Gates on brackets (2)
1. Self ligating system
2. Can get clogged up with plaque but only works when fully closed
246
Why does a pt given power chain need to be seen more frequently
Elastomers lose force very quickly
247
What can be used to stop patient biting on flexible wire
Bumper tubing
248
Temporary anchorage devices (2)
Non osseointegrating mini screw
Sometimes called absolute maximum anchorage
249
Type of anchorage (3)
1. Simple
2. Compound
3. Reciprocal
250
Simple anchorage
Increased root surface area
251
Compound anchorage
Link groups of teeth together
252
Reciprocal anchorage (2)
Same root surface area leads to equal tooth movement
Good for diastemas
253
Types of arch wires (4)
1. SS
2. NiTi
3. CoCr
4. Beta titanium (TMA)
254
Advantages of SS archwire (2)
Slides teeth easier
Formable - loops
255
Force generating components on fixed appliances (4)
1. Powerchain
2. NiTi coils
3. Intra-oral elastics
4. Active ligature
256
Features with high relapse potential (6)
1. Diastema
2. Rotations
3. Palatally ectopic canines
4. Proclamation of LI
5. AOB
6. Instanding upper laterals
257
Average ortho treatment length
18-24 months
258
Average hypodontia/orthognathic ortho case length
24-30 months
259
How often are fixed appliances adjusted
4-8 weeks
260
Initial fixed appliances issues (4)
1. Pain
2. Mucosal irritation
3. Ulceration
4. Appliance breakage
261
Dental reasons to treat class III (3)
1. Attrition
2. Gingival recession
3. Mandibular displacement
262
Class III factors which make tx more difficult (4)
1. Number of teeth in crossbite
2. Skeletal element in aetiology
3. AP discrepancy
4. Presence of AOB
263
Radiographic methods of assessing growth spurts (~3)
Cervical vertebrate maturation on lateral ceph
Hand wrist radiographs
Both low reliability
264
Class III tx options (5)
1. Accept/Monitor
2. Intercept early with URA
3. Growth modification
4. Camoflage
5. Orthognathic
265
When is interceptive tx suitable for class III
If class III incisors due to early contact on permanent incisors
(Mandibular displacement)
266
When can interceptive tx be used in class III to correct 2s in crossbite
When canines high above lateral roots
267
Functional appliances for class III (3)
1. Chin cup
2. Reverse twin block
3. Frankel III
268
Chin Cup (3)
1. Historic
2. Lingual tipping of LI
3. Rotates mandible down and back
269
Frankel III (3)
1. Pellotes labial to UI to hold lip away
2. Palatal arch to procline UI
3. Lower labial bow to retrocline LI
270
Protraction headgear (3)
1. 14hr/day wear
2. Best results early mixed dentition (8-10)
3. Rapid maxillary expansion
271
Class III - Favourable features for camouflage (5)
1. Growth stopped
2. Mild/moderate class III skeletal base
3. Avg or >OB
4. Edge to edge achievable
5. Little/no dentoalveolar compensation
272
Extraction pattern for class III (2)
1. Further back in upper
2. Further forward in lower
273
ANB limits for class III camouflage
Must be >0
274
Full alignment of class III while pt still growing (2)
Don't do
Consider upper alignment only
275
Anodontia
Complete absence of teeth
276
Severe hypodontia
6+ congenitally absent teeth
277
Aetiology of hypodontia (3)
Non-syndromic
Syndromic
Environmental
278
If order of eruption varies
Consider hypodontia
279
Hypodontia - Refer to ortho if (3)
1. Crowding delays eruption
2. Severely infra-occluded teeth with tipping
3. 6+ months contralateral eruption
280
If e's last until the pt is 20
Will last the rest of their lives
281
Space needed for implants for hypodontia patients
7mm
Can look weird if small teeth
