Orthodontics Flashcards
1
Q
How can digit sucking be prevented?
A
Behaviour management therapy
Plasters, gloves, bitter flavoured agents
URA with rake
Habit reversal
2
Q
What are four examples of conditions of tooth movement?
A
Hypodontia
Supernumerary
Early loss of permanent teeth
Late loss of primary teeth
3
Q
What are the four types of supernumerary teeth?
A
Conical
Tuberculate
Odontome
Supplemental
4
Q
What are the anatomical features that influence tooth mobility?
A
Width of pdl
Height of pdl
Inflammation
Number, shape, length of roots
5
Q
What are pathological causes of tooth mobility?
A
Periodontal disease
Periapical abscess
Trauma
External inflammatory resorption
6
Q
When should we intervene in tooth mobility?
A
Progressively increasing
Symptomatic
Creates difficulty with restorative treatment
7
Q
What are the treatment options for an impacted 6?
A
Distal disking of the e
Orthodontic separation
Distalise the 6
Extract e
If under 7, wait 6 months
8
Q
What are the treatment options for an unerupted central incisor?
A
Remove predecessor
If under 9- wait 12 months
If over 9- surgical exposure and orthodontic movement with gold chain
9
Q
What is a balancing extraction?
A
Removal of tooth from opposite side of the same arch to maintain the position of the centreline
10
Q
What is a compensating extraction?
A
Removal of a tooth from the opposing quadrant to maintain buccal occlusion
11
Q
What should you do following Xla of a’s and b’s
A
Do nothing
12
Q
What should you do following Xla of c’s
A
Balance
13
Q
What should you do following Xla of d’s
A
Small shift: balance
14
Q
What should you do following Xla of e’s
A
Space maintainer
15
Q
What is an example of a removable space maintainer?
A
URA (passive)
16
Q
What is an example of a fixed space maintainer?
A
Band and loop
Palatal/lingual arches
17
Q
What factors should be considered for Xla of 6’s
A
Bifurcation of 7’s
8’s present
Class 1 occlusion
Mesial angulation of lower 6
Moderate lower crowding
Mild/moderate upper crowding
18
Q
What is mild crowding measured as?
A
0-4mm
19
Q
What are the treatment options for mild crowding?
A
No Xla
Xla 5
20
Q
What is moderate crowding measured as?
A
5-8mm
21
Q
What is the treatment for moderate crowding?
A
Xla 5s or 4s
22
Q
What is the measurement for severe crowding?
A
> 8mm
23
Q
What is the treatment option for severe crowding?
A
Xla 4s
24
Q
What are the aims of ortho treatment?
A
Stable
Aesthetic
Functional
25
What are the indications for ortho treatment?
Malocclusion
Risk of trauma/disease
Impaired oral function
Unaesthetic
26
What are the contraindications to ortho treatment?
Uncontrolled epilepsy
Poor attendance
Poor OH
27
What are the benefits of ortho treatment?
Increased confidence
Increase dental health
Decrease trauma
28
What are the risks of ortho treatment?
Relapse
Root resorption
Decalcification
29
What are the limitations of ortho treatment?
Teeth only stable in the neutral zone
No effect on skeletal patterns
Movement limited by size and shape of alveolar process
30
What does ARAB stand for?
Active Component
Retention
Anchorage
Baseplate
31
What does Active Component mean?
Induces a displacement force
32
What does Anchorage mean?
Resistance to unwanted tooth movement
32
What does Retention mean?
Resistance to displacement forces
33
What does a Baseplate provide?
Anchorage
Connection
Cohesion
Adhesion
Stability
34
What is Newton's 3rd Law?
For every action, there is an equal and opposite reaction
35
What should be on the lab card for treatment of an anterior cross bite on 12 ?
Aim: Please construct a URA to correct and anterior crossbite on 12
A: z-spring 0.5mm HSSW on 12
R: Adams clasp 0.7mm HSSW on 16, 26, 14, 24
A: yes (moving 1 tooth)
B: self cure PMMA + posterior bite plane
36
What should be on the lab card for treatment of a posterior crossbite?
Aim: Please construct a URA to expand the upper arch
A: Midline palatal screw
R: Adams clasp 0.7mm HSSW on 16, 26, 14, 24
A: Reciprocal anchorage
B: Self cure PMMA + posterior bite plane
37
How often should the active component be activated if in the anterior region?
Once a month
38
How often should the active component be activated if in the posterior region?
Once a week
39
What is the rule for tooth movement in association with bone remodelling?
Only 1-2 teeth should be moving 1mm per month
40
What are the options for retentive components?
Adams clasp 0.7mm (0.6mm in deciduous)
Southend clasp 0.7mm
Labial bow 0.7mm
C-clasp 0.7mm
41
What is the effect of thumb sucking on the skeletal pattern?
Proclamation of upper anteriors
Retroclination of lower anteriors
Localised anterior open bite
Incomplete open bite
Narrow upper arch with unilateral posterior cross bite
42
What is a class I incisor relationship?
The lower incisors occlude with or lie immediately below the cingulum plateau of the upper incisors
43
What is a class I incisor relationship?
The lower incisors occlude with or lie immediately below the cingulum plateau of the upper incisors
44
What is a class II div I incisor relationship?
The upper incisors are proclined (increased overjet).
The lower incisors occlude posterior to the upper incisors
45
What is a class II div II incisor relationship?
The upper incisors are retro lines (decreased overjet).
The lower incisors occlude posterior to the upper incisors
46
What is a class III incisor relationship?
The lower incisal edge occludes anterior to the cingulum plateau of the upper incisors
47
What is a class I molar relationship?
The mesiobuccal cusp of the upper first permanent molar occludes with the mesiobuccal groove of the lower first permanent molar
48
What is a class II molar relationship?
The mesiobuccal cusp of the upper first permanent molar occludes anterior to the mesiobuccal groove of the lower first permanent molar
49
What is a class III molar relationship?
The mesiobuccal cusp of the upper first permanent molar occludes posterior to the mesiobuccal groove of the lower first permanent molar
50
What is a class I canine relationship?
The mesial slope of the upper canine lies within the canine-first premolar embrasure
51
What is a class II canine relationship?
The mesial slope of the upper canine lies in front of the distal slope of the lower canine
52
What is a class III canine relationship?
The mesial slope of the upper canine lies behind the distal slope of the lower canine
53
What is local malocclusion?
Where the occlusion of 1-3 teeth on either arch prevents the teeth from exhibiting ideal occlusion
54
What are reasons for abnormalities in tooth number?
Early exfoliation
Unplanned loss of permanent teeth
Hypodontia
Loss of permanent teeth
55
How can we measure anterio-posterio skeletal relationship?
Measuring the ANB angle in a cephalogram
Measuring clinically using two fingers to establish the relationship between the maxilla and mandible
56
How can we measure the vertical skeletal relationship?
FAMP
LAFH:FAFH
57
How should the head be positioned for a cephalogram?
Frankfort plane
58
What factors promote osteoclastic bone resorption?
Interleukin-1
Prostaglandin E2
RANKL
Colony Stimulating Factor
59
What is the force applied for tooth movement?
10-20g
60
What are the factors affecting the rate of tooth movement?
Magnitude of force
Age of patient
Duration of force
Anatomy of bone
61
Why is an orthodontic assessment carried out?
Determine the nature of any malocclusion present
Identify underlying causes
Decide if treatment is indicated and either refer or devise a treatment plan
62
When is an orthodontic assessment carried out?
Brief examination aged 9 years
Comprehensive examination when premolars and canines erupt (11-12 years)
When older patients first present
If malocclusion develops later in life
63
What are the features of an ideal occlusion in regard to molar relationship?
The distal surface of the disco-buccal cusp of the upper first permanent molar occludes with the mesial surface of the mesial buccal cusp of the lower second permanent molar
64
What are the features of an ideal occlusion? (Andrews 6 keys)
Molar relationship
Crown angulation
Crown inclination
No rotations
No spaces
Flat occlusal planes
65
What is normal occlusion?
More commonly observed than ideal occlusion
Minor deviations that do not constitute an aesthetic or functional problem
Malocclusions are more significant deviations from the ideal that may be considered unsatisfactory
May require treatment, but patient factors may influence decision
66
What are the features of a history for an orthodontic patient at assessment?
Presenting complaint
How much does it bother the patient
History of presenting complaint
Past medical history
Past dental history
Social/family history
67
What medical conditions are a contra-indication to orthodontic treatment?
Allergy to Ni or Latex
Epilepsy/drugs
Drugs
Imaging
68
What are the features of past dental history for an orthodontic patient at assessment?
Frequency of attendance
Nature of previous treatment
Co-operation with previous treatment
Trauma to permanent dentition
69
What are the features of social/family history for an orthodontic patient at assessment?
Travelling distance/time
Car owner/public transport
Parents work
School exams
70
What are the features of a habit history for an orthodontic patient at assessment?
Thumb sucking
Lower lip sucking
Tongue thrust
Chewing finger nails
71
What are the features of an extra-oral exam for an orthodontic patient at assessment?
Palpate skeletal bases
Soft tissue
TMJ
72
What should you compare an orthodontic patient to their parent for?
Malocclusion
Growth potential
73
What planes is the facial skeletal pattern considered in?
Antero-posterior
Vertical
Transverse
74
How can a skeletal assessment be carried out?
Visual assessment
Palpate skeletal bases
75
What are the options for AP skeletal relationship?
Class I
Class II
Class III
76
What is a Class I skeletal relationship?
Maxilla 2-3mm in front of mandible
77
What is a Class II skeletal relationship?
Maxilla more than 3mm in front of mandible
78
What is a Class III skeletal relationship?
Mandible in front of maxilla
79
What are the vertical measurements for a skeletal assessment?
Frankfort-Mandibular Plane Angle (FMPA)
80
What are the lateral measurements for a skeletal assessment?
Mid saggital reference line
81
What are the soft tissue features of an intra-oral exam for an orthodontic patient?
Lip: competence, lower lip level, lower lip activity
Tongue: position, habitual and swallowing
Habits: tongue, digit sucking
Speech: lisping
82
What does lip incompetence indicate?
End of treatment instability
83
What does a hyperactive lower lip indicate?
End of treatment instability
84
What can a hyperactive lower lip result in?
Retroclined lower molars
85
What is tongue thrust associated with?
Anterior open bite
86
What are the occlusal features of a digit sucking habit?
Proclination of upper anteriors
Retroclination of lower anteriors
Localised AOB or incomplete OB
Narrow upper arch +/- unilateral posterior crossbite
87
What should be focused on when carrying out an extra oral exam on the TMJ?
Path of closure
Range of movement
Pain, click from joint
Deviation on opening
Muscle tenderness
Mandubular displacement
88
What should be focused on when carrying out an intra-oral exam on an orthodontic patient?
Oral hygiene and periodontal health
Teeth present
Teeth of poor prognosis
Assess crowding/spacing/rotations
Inclination/angulation
Palpate for canines if not erupted
Note abnormal teeth
89
What should be looked at when carrying out out an intra-oral exam for an orthodontic patients lower arch?
Degree of crowding: uncrowded, mild, moderate, severe
Presence of rotations
Inclination of canines- mesial, upright, distal
Angulation of incisors to mandibular plane: upright, proclaimed, retroclined
90
What should be looked at when carrying out out an intra-oral exam for an orthodontic patients upper arch?
Degree of crowding: mild. moderate, severe
Presence of rotations
Inclination of canines- mesial, upright, distal
Angulation of incisors to Frankfort plane- upright, proclaimed, retroclined
91
What is the approximate angle of the upper incisors to Frankfort plane?
110 degrees
92
What should be focused on when assessing teeth in occlusion for orthodontic patients?
Incisor relationship
Overjet
Overbite/open bite
Molar relationship
Canine relationship
Cross bites
Centre lines
93
What is a class I incisor relationship?
The mandibular incisor edges lie or are below the cingulum plateau of the maxillary incisors
94
What is a class II div 1 incisor relationship?
Mandibular incisor edges lie posterior to the cingulum plateau of the maxillary incisors
Maxillary incisors proclined
95
What is a class II div 2 incisor relationship?
Mandibular incisor edges lie posterior to the cingulum plateau of the maxillary incisors
Maxillary incisors retroclined
96
What is a class III incisor relationship?
Mandibular incisors edges lie anterior to the cingulum plateau of the maxillary central incisors
97
What is a class I molar relationship?
The MB cusp of the maxillary first permanent molar occludes with the MB groove of the mandibular first permanent molar
98
What is a class I canine relationship?
The mesial incline of the maxillary canine occludes with the distal incline of the mandibular canine
The distal incline of the maxillary canine occludes with the mesial incline of the mandibular first premolar
99
What is a class II molar relationship?
MB groove of mandibular first molar is distal to the MB cusp of the maxillary first molar
100
What is a class III canine relationship?
The mesial incline of the maxillary canine occludes anteriorly with the distal incline of the mandibular canine
The distal surface of the mandibular canine is posterior to the mesial surface of the maxillary canine by at least the width of the premolar
101
What is a class III molar relationship?
MB cusp of the maxillary first premolar occludes distally to the MB groove of the mandibular first molar
102
What is a class III canine relationship?
Distal surface of the mandibular canines are mesial to the mesial surface of the maxillary canines by at least the width of a premolar
Mandibular incisors are in complete crossbite
103
What special investigations can be carried out for patients at the orthodontic assessment?
Radiogrpahic: OPT, maxillary anterior occlusal, lat ceph
Vitality tests
Study models
Photographs
104
What do you do with the information gathered from an orthodontic assessment?
Summarise the important points
Assess treatment need (IOTN)
Devise treatment aims if appropriate
Plan treatment
105
What are the risks with orthodontic treatment?
Decalcification
Relapse
Root resorption
106
What is the IOTN?
Index of Orthodontic Treatment Need
A rating system that was developed to assist in determining the potential impact of malocclusion on an individual's dental health and psychosocial well-being
107
What is the aesthetic component of the IOTN?
10 colour photographs showing different levels of dental attractiveness
Orthodontist must match the patients to these photographs
108
What is the dental component of the IOTN?
Records the various occlusal traits of a malocclusion that would increase the morbidity of the dentition and surrounding structure
Measured in 5 grades
109
What would grade 1-4 aesthetic component of the IOTN indicate?
No or minor requirement for treatment
110
What would grade 5-7 aesthetic component of the IOTN indicate?
Moderate/borderline need for treatment
111
What would grade 9-10 aesthetic component of the IOTN indicate?
Requires orthodontic treatment
112
When are coloured vs black and white photographs used for the IOTN?
Coloured photographs used with patients displaying range of dental attractiveness
Monochrome photographs used for the assessment on dental casts
113
What is the advantage of monochrome photographs in the aesthetic component of the IOTN?
Advantage that whoever is rating will not be influenced by a patient's oral hygiene, gingival conditions or poor colour matches in restorations
114
What does MOCDO stand for?
Missing Teeth
Overjets
Crossbones
Displacement of contact points
Overbites
115
What is 5i on the IOTN?
Impacted teeth (except 8s) due to crowding, displacement, the presence of supernumerary teeth, retained deciduous teeth and any other pathological cause
116
What is 5h on the IOTN?
Extensive hypodontia with restorative implications (more than 1 tooth missing in any quadrant) requiring pre-restorative orthodontics
117
What is 5a on the IOTN?
Increased overset greater than 9mm
118
What is 5m on the IOTN?
Reverse overject greater than 3.5mm with reported masticatory and speech difficulties
119
What is 5p on the IOTN?
Defects of cleft lip and palate and other craniofacial anomalies
120
What is 5s on the IOTN?
Submerged deciduous teeth
121
What does grade 5 on IOTN indicate?
Severe dental health problems requiring treatment
122
What is grade 4 on IOTN indicate?
Dental health problems requiring treatment
123
What is grade 4h on IOTN?
Less extensive hypodontia requiring pre-restorative orthodontics or orthodontics to obviate the need for a prosthesis
124
What is grade 4a on IOTN?
Increased overjet greater than 6mm but less than or equal to 9mm
125
What is grade 4b on IOTN?
Reverse overset greater than 3.5mm with no recorded masticatory or speech difficulties
126
What is grade 4m on IOTN?
Reverse overjet greater than 1mm but less than 3.5mm with recorded masticatory and speech difficulties
127
What is grade 4c on IOTN?
Anterior or posterior crossbites with greater than 2mm discrepancy between retruded contact position (RCP) and intercuspal position (ICP)
128
What is grade 4l on IOTN?
Posterior lingual crossbite with no functional occlusal contact in one buccal segment
129
What is grade 4d on IOTN?
Severe contact displacements greater than 4mm
130
What is grade 4e on IOTN?
Extreme lateral or anterior open bites greater than 4mm
131
What is grade 4f on IOTN?
Increased and complete overbite with gingival or palatal trauma
132
What is grade 4t on IOTN?
Partially erupted teeth, tipped and impacted against adjacent teeth
133
What is grade 4x on IOTN?
Presence of supernumerary teeth
134
What is grade 3 on IOTN?
Borderline treatment need
135
What is grade 3a on IOTN?
Increased overjet greater than 3.5mm but less than or equal to 6mm with incompetent lips
136
What is grade 3b on IOTN?
Reverse overset greater than 1mm but less than or equal to 3.5mm
137
What is grade 3c on IOTN?
Anterior or posterior crossbites with greater than 1mm but less than or equal to 2mm discrepancy between RCP and ICP
138
What is grade 3d on IOTN?
Contact displacements greater than or equal to 4mm
139
What is grade 3e on IOTN?
Lateral or anterior open-bite greater than 2mm but less than or equal to 4mm
140
What is grade 3f on IOTN?
Deep overbite complete on gingival or palatal tissues, but no trauma
141
What is grade 2 on IOTN?
Negligible treatment need
142
What is grade 2a on IOTN?
Increased overjet greater than 3.5mm but less than or equal to 6mm with competent lips
143
What is grade 2b on IOTN?
Reverse overset greater than 0mm but less than or equal to 1mm
144
What is grade 2c on IOTN?
Anterior or posterior crossbite with less than or equal to 1mm discrepancy between RCP and ICP
145
What is grade 2d on IOTN?
Contact point displacements greater than 1mm but less than or equal to 2mm
146
What is grade 2e on IOTN?
Anterior or posterior open bite greater than 1mm but less than or equal to 2mm
147
What is grade 2f on IOTN?
Increased overbite greater than or equal to 3.5mm without gingival contact
148
What is grade 2g on IOTN?
Pre-normal or post-normal occlusions with no other anomalies (inc up to half a unit discrepancy)
149
What is a unit in orthodontics?
Length of a premolar
150
What is grade 1 IOTN?
No treatment need
Extremely minor malocclusions including contact displacements less than 1mm
151
What rules apply when using the dental health component of the IOTN on study casts?
Overjets 3-5-6mm: assume incompetent lips and award grade 3a
Crossbites: assume a discrepancy between RCP and ICP of 3mm and award grade 4c
Reverse overjets: assume masticatory or speech problems are present
152
What does the top left of the IOTN ruler measure?
Overjet
153
What does the bottom left of the IOTN ruler measure?
Reverse overjet
154
What does the right of the IOTN ruler measure?
Contact point displacement and open bite
155
When can a tooth be regarded as impacted?
If the space between the two teeth next to it is less than or equal to 4mm
156
When is there considered to be an anterior crossbite?
1 to 3 incisors are in lingual occlusion
157
When is there considered to be a posterior crossbite?
Cusp to cusp or in full crossbite
158
When are submerged deciduous teeth considered in IOTN?
If only 2 cusps are visible and/or the adjacent teeth are severely tipped towards each other and closely approximated
159
What IOTN is necessary for NHS treatment?
DHC- >4 (borderline 3)
Aesthetic component- >6
159
160
What are the indications for orthodontic referral during the deciduous dentition?
Severe skeletal discrepancies
Severely delayed dental development
Missing/supplemental teeth
History of head and neck radiotherapy with/without chemotherapy
Advice for balancing/compensating extractions
161
What are the indications for orthodontic referral during the mixed dentition?
Severe skeletal patterns where early treatment may be appropriate e.g. developing class II/III
Dental anomalies e.g. double teeth, dens in dente, talon cusps
Developmentally missing permanent teeth
Supernumerary teeth
Teeth in unfavourable positions e.g. canines
Impacted first permanent molars
Infraoccluded teeth
Crossbites
Extraction advice where severe crowding evident or first molars have poor prognosis
Advice following trauma to permanent teeth
162
What are the indications for orthodontic referral during the permanent dentition?
Based on IOTN
163
When is an orthodontic assessment carried out?
Brief examination at 9 years old
Comprehensive examination when premolars and canines erupt (11-12 years)
When older patients first present
If malocclusion develops later in life
164
What are the Andrew's 6 keys?
Molar relationship
Crown angulation (mesio-distal tip)
Crown inclination
No rotations
No spaces
Flat occlusal plane
165
What is normal occlusion?
Minor deviations that do not constitute an aesthetic or functional problem
166
What are malocclusions?
More significant deviations from the ideal that may be considered unsatisfactory (aethetically or functionally)
167
What should be included in an orthodontic diagnosis?
Description of the malocclusion
Determine the cause of the malocclusion
Are the causes dentoalveolar or skeletal
168
What are examples of causes of malocclusion?
Small teeth - spacing
Early loss of deciduous teeth - crowding
Digit sucking - proclination and increased OJ
169
What diagnoses can be obtained from a lateral cephalogram?
AP skeletal
Vertical skeletal
Class III incisors
170
Why is a correct orthodontic diagnosis important?
Orthodontic appliances can move teeth very well but can modify skeletal relationship minimally
A severe skeletal discrepancy may require surgical intervention
171
What are the objectives of orthodontic treatment?
Stable
Functional
Aesthetic
172
How should orthodontic treatment planning be carried out?
Treatment plan in stages
173
What are the main two treatment options of orthodontic treatment?
Full correction of malocclusion
Compromise treatment
174
What are the aims of a full correction of malocclusion?
Class I incisor relationship (OJ/OB normal)
Class I canine relationship
Class I molar relationship (can accept class II)
No rotations, spaces, flat occlusal plane (Andrew's six keys)
175
What are the aims of a compromise treatment in orthodontics?
Correct certain aspects accepting others
May have to work within adverse skeletal pattern and leave residual OJ particularly in adults
176
What are the 4 stages of an orthodontic treatment plan?
1. Plan around the lower arch (angulation of LLS is stable)
2. Decide on treatment in lower (ext/nonext)
3. Build upper arch around lower, aim for class I incisor and canine relationship (OJ and OB normal)
4. Decide on molar relationship: class I or full unit class II molar relationship
177
What should you look at when examining the lower arch in orthodontic treatment planning?
Crowding/ Angulation of incisors and mandibular plane
Angulation of the canines/ centre lines
Curve of spee
178
What decisions need to be made when examining the lower arch in orthodontic planning?
Is space required?
What are the options?
Extraction or non-extraction?
179
What should you look at when examining the upper arch?
Crowding/ angulation of incisors to the maxillary plane
Angulation of the canines/ centreline
180
What should be focused on when examining teeth in occlusion?
Incisor relationship
OJ
OB (curve of spee)
Centrelines
Canine relationship
Molar relationship
181
What should you do in a crowding assessment?
Measure space available and space required
Overlap technique
182
What is the definition of mild crowding?
0-4mm discrepancy between space available and required
183
What is the definition of moderate crowding?
5-8mm discrepancy between space available and required
184
What is the definition of severe crowding?
>8mm discrepancy between space available and required
185
What is the treatment of mild crowding?
Non extraction: stripping
Extract 5's
186
What is the treatment of moderate crowding?
Extract 5's
Extract 4's
187
What is the treatment of severe crowding?
Extract 4's
188
What are the general principles for upper arch crowding if there was a lower arch extraction?
Extract in upper arch (MR class I)
189
What are the general principles for upper arch crowding if there was not a lower arch extraction?
Extract in upper arch (MR class II) or distalise UBS using headgear (MR class I)
190
What considerations should be made when treating an overset?
Can it be done with tipping or bodily movements
191
What are the orthodontic treatment options?
Accept malocclusion
Extractions only
URA
Functional appliances
Fixed appliances
Complex treatment involving orthodontics and restorative treatment or orthodontics and orthognathic surgery
192
What are the limitations of orthodontic treatment?
Effects of orthodontic treatment are almost purely dento-alveolar and tooth movement with little effect on the skeletal pattern
Tooth movements are limited by the shape of the size of alveolar processes
Teeth will only remain stable in a position where there is equilibrium between the forces of the soft tissues, the occlusion and the periodontal structures. All other positions are unstable and will be prone to relapse
193
What orthodontic treatment should be carried out during the adolescent growth spurt?
Treatments that rely on growth: overbite reduction, functional appliance therapy
194
What are the treatment options for ectopic canines?
Extract c’s
Surgical exposure and ortho
Leave
195
What are the treatment options for ectopic canines?
Extract c’s
Surgical exposure and ortho
Leave
196
What is functional occlusion?
Absence of pathology/interference
197
What is a mutually protected occlusion?
Gold standard; canine guidance,
198
When is a fixed appliance used?
Multiple tooth malpositions
199
When are functional appliances used?
Corrects sagital discrepancies in class II d1 cases
200
When are removable appliances used?
Tipping teerh
201
What does MOCDOO stand for?
Missing teeth
Overjet
Crossbite
Displacement of contact points
Overbite
202
What are the checks for URA fitting?
Check correct patient
Check design matches prescription
Check for sharp areas and pre-existing damage
Check for trauma/blanching
Check posterior retention
Check anterior retention
Activate appliance
Demonstrate insertion and removal
Book review
203
What are the patient instructions for a URA?
May feel big and bulky
May affect speech
May cause excessive saliva
May be painful
Must wear 24/7
Clean with a soft bristle brush
Take out for sports
Avoids sticky/hot foods
Non-compliance will increase treatment length
Provide emergency contact details
204
What are the incidences of malocclusion?
Class I: 67-72%
Class II div I: 15-20%
Class II div II: 10%
Class III: 3%
205
What is the rationale behind treating a class II div 1?
Concerns about aesthetics
Concern about dental health
206
What are the dental health implications of class II div I?
Risk of trauma to prominent incisors
Overjet <9mm x2 more likely to suffer trauma
IOTN 5a (most need of tx)
207
What is the skeletal pattern associated with a class II div II?
Class II skeletal pattern
208
What type of mandible;maxilla condition is associated with class II div II?
Retrognathic mandible
(Sometimes maxillary protrusion)
209
What are the causes of an overjet?
Skeletal pattern
Tooth inclination
Combination of both
210
What are the causes of an overjet?
Skeletal pattern
Tooth inclination
Combination of both
211
What is the normal range of SNA?
81 +/- 3
212
What is the normal range for SNB?
78 +/- 3
213
What is the normal rage for ANB?
3 +/- 2
214
What is the normal range of MxP/MnP?
27 +/- 4
215
What is the normal range of MxP/MnP?
27 +/- 4
216
What is the normal range of Ul/MxP?
109 +/- 6
217
What is the normal range of LI/MnP?
93 +/- 6
218
What is the normal range of LI/MnP?
93 +/- 6
219
What is the normal value for LAFH/TAFH?
55%
220
What is the effect of class II div I on soft tissues?
Incompetent lips due to prominence of incisors and/or underlying skeletal pattern
Lower lip trap can be aetiological in an increased overjet
221
What is the effect of class II div I on soft tissues?
Incompetent lips due to prominence of incisors and/or underlying skeletal pattern
Lower lip trap can be aetiological in an increased overjet
222
What are the methods of achieving an anterior oral seal?
Lip to lip seal by activity of circum-oral musculature
Mandible postured to allow lips to meet
Or
Lower lip drawn up behind upper incisors
Tongue placed forward between incisors to lower lip
Or
Combination of both
223
What are the dental factors associated with a class II div II?
Increased overjet
Overbite varies
Can see good alignment, crowding or spacing
Molar relationship
Habitually parted lips may lead to drying of gingiva and exacerbation of any pre-existing gingivitis
224
What are examples of sucking habits?
Thumb
Fingers
Blanket
Lip
Combination
225
What are the occlusal features of a sucking habit?
Proclination of upper anterior
Retroclination of lower anterior
Localised AOB or incomplete OB
Narrow upper arch (potential unilateral post CB)
226
How can you stop a sucking habit?
Reinforcement
Removable appliance (habit breaker)
Fixed appliance (habit breaker)
227
What are the management options of a class II div I?
Accept
Attempt growth modification
Simple tipping of teeth
Camouflage
Orthognathic surgery
228
When would you accept a class II div I?
Mildly increased OJ
Significant OJ but not unhappy
Consider mouthguard
229
What is the aim of headgear in a patient with class II div I?
Try and restrain growth of the maxilla horizontally and/or vertically
230
What is the incidence of class III malocclusion in UK?
3-7%
231
Where is there a higher incidence of class III malocclusion?
Asia
232
What is associated with the genetic aetiology of class III malocclusion?
Habsburg Family
Controversy about pattern of transmission
233
What is associated with the genetic aetiology of class III malocclusion?
Habsburg Family
Controversy about pattern of transmission
234
What are the environmental aetiological factors associated with class III malocclusion?
Cleft lip and palate
Acromegaly
235
What may the skeletal aetiology of class III malocclusion be due to?
Small maxilla
Large mandible
Combination of both
236
What does the greater the AP discrepancy in class III malocclusion mean?
More complex —> more difficult to treat
237
What does increased FMPA and anterior open bite mean in class III malocclusion?
More complex to treat
238
What are the dental features of a class III malocclusion?
Class III incisor relationship
Class III molar relationship (not always)
Reverse overjet
Reduced overbite, anterior open bite
Crossbites- anterior, buccal
Crowding/spacing
Dentoalveolar compensation
Tendency for displacements on closing
239
What is the alignment like in class III malocclusion?
Maxilla often crowded
Mandible often aligned or spaced
240
What are the features of dentoalveolar compensation in class III malocclusion?
Proclined upper incisors
Retroclined lower incisors
241
What is the role of soft tissues in class III malocclusion?
Not usually aetiological but encourages dentoalveolar compensation
242
What is the role of soft tissues in class III malocclusion?
Not usually aetiological but encourages dentoalveolar compensation
243
How do the soft tissues encourage class III malocclusion via dentoalveolar compensation?
Tongue proclines the upper incisors
Lower lip retroclines lower incisors
244
Why should a class III malocclusion be treated?
Aesthetics
Dental health reasons
Function
245
Why should a class III malocclusion be treated?
Aesthetics
Dental health reasons
Function
246
What are aesthetic reasons to treat class III malocclusion?
Dental
Profile concerns
247
What are aesthetic reasons to treat class III malocclusion?
Dental
Profile concerns
248
What are dental health reasons to treat class III malocclusion?
Attrition
Gingival recession
Mandibular displacement
249
What are functional reasons to treat a class III malocclusion?
Speech
Mastication
250
What factors can make treatment of class III malocclusion more difficult?
Increased number of teeth in anterior crossbite
Skeletal element in aetiology
Increased AP discrepancy
Presence of anterior openbite
251
What is the role of facial growth on the treatment of class III malocclusion?
Tends to be unfavourable
Avoid irreversible treatment until growth has stopped
252
How can you predict a growth spurt?
Height and weight charts
Cervical vertebral maturation (CVM) on lateral cephalogram
Hand risk radiographs
253
What are the downsides of cervical vertebral maturation on lat ceph?
Difficult to reproduce
Poor reliability and validity
254
What are the downsides of hand wrist radiographs?
Low reliability
Risks of repeated radiography
255
What are the management options of class III malocclusions?
Accept/monitor
Intercept early with URA
Growth modification
Camouflage
Combined orthognathic/orthodontic treatment
256
When would you decide to accept/monitor a class III malocclusion?
Mild class III, unsure how growth/development will progress
No concerns/dental health indications (no displacements/attrition)
257
What growth modification treatments can be provided to class III malocclusion cases?
Functional appliance
Head gear
TADs
258
What is the aim of camouflage in class III malocclusion?
Accept underlying skeletal relationship
Correct incisors to class I
259
What is the aim of camouflage in class III malocclusion?
Accept underlying skeletal relationship
Correct incisors to class I
260
When is interceptive treatment in class III malocclusion indicated?
If class III incisors have developed due to early contact on permanent incisors
Correction of anterior crossbite in mixed dentition has the advantage that forward mandibular growth may be counter balanced by some dentoalveolar compensation
Suitable for correcting a lateral incisors crossbite if permanent canines are high above lateral rooots
261
What is the aim of growth modification?
Reducing and/or redirecting mandibular growth and encouraging maxillary growth
262
What are examples of functional appliances?
Chin cup
Reverse twin block
Frankel III
263
What growth modification device combination can be used for class III malocclusion?
Protraction headgear with/without rapid maxillary expansion
264
How does a chip cup work?
Rotates mandible down and back
265
How does a Frankel III work?
Pelllotes (shields) labial to upper incisors to hold lip away
Palatal arch to procline the upper incisors
Lower labial bow to retrocline the lower incisors
266
What are the features of a protraction head gear?
Co-operative patient
14hours/day
400g/side
Best results when used in early mixed dentition (8-10 years)
267
What are the features of bollard implants?
Used in late mixed and permanent dentition
Infrazygomatic crest and lower canine region
Mucoperiosteal flaps need to be raised for insertion and removal
268
What is the aim of orthodontic camouflage?
Accept underlying skeletal relationship and aim for class I incisors
269
What are the favourable features for orthodontic camouflage?
Growth stopped
Mild to moderate class III skeletal base ANB not <0
Average or increased overbite
Able to reach edge to edge incisor relationship
Little or no dentoalveolar compensation
270
What is the extraction pattern in orthodontic camouflage?
Extract further back in upper arch
Extract further forward in lower arch
(Upper 5s, lower 4’s)
271
What are the aims of orthodontic camouflage in class III malocclusion?
Procline upper incisors
Retrocline lower incisors
Correct overjet
272
What is orthognathic surgery?
Surgical manipulation of the mandible and/or maxilla to produce optimal dentofacial aesthetics and function
273
When is orthognathic surgery indicated?
Patient has aesthetic/functional concerns
Growth is completed
Moderate/servere skeletal discrepancy
274
What is the MDT for orthognathic surgery?
Orthodontist
Maxilofacial surgeon
Technician
Psychologist
275
What are the stages of orthognathic surgery?
Pre surgical orthodontics (18 months): level, align, co-ordinate and decompensate
Uppers 109, lowers 90
Orthognathic surgery to reposition the jaws
Post surgical orthodontics (6 months)
276
What is the GDP role in class III malocclusion?
Identify class III malocclusion
Refer to hospital service/specialist practitioner
277
What are two types of frenectomy?
V to Y frenoplasty
Z-plasty
278
What are examples of soft tissue oral surgery for orthodontics?
Frenectomy
Impacted canines
Impacted premolar exposures
279
What are example soft tissue treatments for impacted canines?
Buccal apically repositioned flap
Palatal open exposure
280
What are examples of hard tissue oral surgery for orthodontics?
Impacted canines
Premolars
Extractions
Submerged retained deciduous teeth
Implants
Mini-implants
Orthographic surgery
281
What are examples of hard tissue treatments for impacted canines?
Buccal apically repositioned flap with bone removal
Palatal open exposure with bone removal
Buccal or palatal closed exposure with gold chain attachment
Extraction
282
What are examples of hard tissue procedures from premolars in ortho?
Extraction
Exposure of impacted premolars with bone removal
283
What are examples of hard tissue procedures from premolars in ortho?
Extraction
Exposure of impacted premolars with bone removal
284
What are the treatment options for impacted canines?
Leave alone and monitor
Extract the canine
Surgical exposure and orthodontic alignment- mini-implants, corticotomy
Transplant
285
What are the indications for canine transplant?
We cannot reasonably get a result by exposure and traction
There is a potential for damage to other teeth
Space is available or can be made available without premolar extraction
Older patient seeking quick solution
286
What are the splints used following canine transplant?
Old chrome/cobalt cap splint
Titanium trauma splint
287
What are the benefits of implants in ortho?
Implants provide the qualities of an ideal orthodontic anchor
Patient compliance unnecessary
Absolute anchorage as there is no pdl
Easily used under a variety of treatment modalities
Easily placed
Removable if necessary
288
How long do you splint a transplanted tooth?
2 weeks
289
What are orthodontic implants made of and why?
Stainless steel
So they can be removed (titanium fuses to bone)
290
What is a corticotomy?
Breakdown of cortical bone to facilitate tooth movement
291
How many births are affected by Cleft Lip/Palate?
1 in 700
292
What is the biggest environmental factor for CLP?
Social deprivation
293
What is the CLP to CP ratio in England and Wales compared to Scotland?
2;1 England and Wales
1:1 Scotland
294
What was the effect of the smoking ban on CLP?
10% decrease in cases
295
How many UK births are affected by cleft lip/palate in UK 20-21?
898
296
What are the genetic aetiology for CLP?
Syndromes
Family history
Sex ratio
Laterality (more common on left than right)
Ethnic distinction
297
What is the environmental aetiology of CLP?
Social deprivation
Smoking
Alcohol
Anti-epileptics
Multi-vitamins
298
What are the implications of CLP?
Aesthetics
Speech
Dental
Hearing and Airway
Other anomalies
299
What is the multidisciplinary team for CLP?
CNS
Surgeon
SLT
Dental Team
ENT
Airways
Psychology
Co-ordinator
Genetics
300
What is the patient journey of a CLP patient?
3 months: Lip closure
6-12 months: Palate closure
8-10 years: Alveolar bone graft
12-15 years: Definitive orthodontics
18-20 years: Surgery
301
What are the dental implications of CLP?
Missing teeth
Impacted teeth
Crowding
Growth
Caries
302
Why is CLP associated with hearing issues
Levator veli palatini attached to Eustachian tube
303
Why is palate closure not until 6-12 months?
Children are obligate nasal breathers until 6 months
304
How does a CLP bone graft work?
Take bone from hip and transplant to alveolus
Allow tooth (canine) to erupt through
Orthodontics followed to align
305
What tooth is usually missing in CLP?
Lateral incisor
306
What % of CLP patients have a class III malocclusion?
20% (compared to 3% general population)
307
Why is there a higher rate of caries in CLP?
Hypoplastic
Smaller teeth
Poorer clearance
308
Why do adults seek orthodontic treatment?
To improve their dental appearance- refused treatment as a child, lack of earlier opportunity, unhappy with earlier treatment (relapse, poor initial treatment)
Adjunctive- facilitate restorative treatment, after periodontal drift, part of surgical correction of jaw discrepancy
309
What are the main differences between adult and children orthodontic patients?
Lack of growth
Periodontal disease
Missing/heavily restored teeth
Physiological factors
Adult motivation
310
What are the limitations to orthodontic treatment associated with adult growth?
Adults are non-growing
Growth modification not possible
Overbite correction more difficult- may need tooth intrusion
Midpalatal suture closed- can only expand maxillary base with surgery
311
What is the effect of adult periodontal tissues on orthodontic treatment?
Patients need careful periodontal assessment
Previous support loss does not preclude ortho treatment, but active periodontal disease does
312
What does loss of tooth support due to periodontal disease lead to in association with orthodontic treatment?
Tooth centre of rotation moving apically
Anchorage value reducing
313
What is the effect of missing teeth/restorations in adult ortho?
Tooth loss leading to drifting/tilting
More likely to be restored- can complicate bonding
RCT okay if obturated correctly and symptomless
314
What are the physiological factors affecting adult ortho?
Decreased cell turn over, initial movement can be slower
Must use lighter forces
315
What is the basis of adult motivation in orthodontic treatment?
Often very well motivated
May request ‘aesthetic’ appliances
316
What are the methods of using adult orthodontic treatment as an adjunctive treatment to restorative?
Upright abutments to aid restoration
Intrusion of overerupted teeth
Extrusion to increase crown length
317
How may adult orthodontics be used as an adjunct to Perio treatment?
Perio may lead to tooth migration, proclined incisors, spacing and increased overbite
318
How may adult orthodontics be used as an adjunct to orthognathic surgery?”
Pre-surgically - align and coordinate dental arches and decompensate incisors
Post surgically
319
What are examples of short term orthodontics?
Clear aligners
Inman aligner
Six Month Smile
320
What is six month smile?
Preadjusted brackets in trays for indirect bonding, plus niti arch wires
321
What are examples of clear aligner brands?
New smile
Smile white
Straight Teeth Direct
Invisalign
Dr Smile
Virtuoso
322
What is the incidence of class I incisors?
60%
323
What is the incidence of class II div 1?
15-20%
324
What is the incidence of class II div 2?
5-18%
325
What is the incidence of class III incisor relationship?
3-8%
326
What skeletal pattern is associated with class 2 div 2?
Mild or moderate class 2
327
What vertical skeletal pattern is associated with class 2 div 2?
Reduced FMPA
Associated with forward rotational pattern of growth in mandible
Prominent chin
328
What are the soft tissue features of a class 2 div 2?
High resting lower lip line: reduced lower facial height and retroclined upper incisors
Marked labio-mental fold
High masseteric forces
329
Why is there a shortened upper 2 clinical crown in class 2 div 2?
Escaping the effect of the lower lip line
Trap lower lip
330
What are the dental features of class 2 div 2?
Retroclined upper central
Upper 2s often crowded- mesiolabially rotated, may be normal or proclined
Reduced arch length
Poor cingulum in lateral incisors
Increased/Deep overbite
Lower incisors may occlude with the upper incisors or palatal mucosa
Reduced OJ
Class II buccal segment
Increased inter-incisal angle
331
What is the prevalence of developmental dental anomalies in class 2 div 2?
50% of cases have congentital dental anomaly
33% have impacted canines
332
Why treat a class 2 div 2?
Aesthetic concerns
Dental health concerns- traumatic overbite (4f)
333
What does treatment of class II div II depend on?
Severity of malocclusion
Age and motivation of patient
Dental health concerns
Patient concerns
334
What are the options for orthodontic management of class II div II?
Accept
Growth modification
Camouflage
Orthognathic treatment
335
When should a class II div II malocclusion be accepted?
Acceptable aesthetics
Patient not concerned/suitable for tx
Overbite not a significant problem
336
What group of patients are suitable for growth modification?
Adolescent growth spurt
Boys 12-16
Girls 10-14
337
What class II div II patients are suitable for growth modification?
Mild to moderate skeletal pattern
Growing patient
338
What is the effect of growth modification in class II div II patients?
Converts class II div 2 into class II div 1
339
What is the aim of functional appliances in class II div 2?
Proclination of upper incisors
340
What are the options for functional appliances in class II div II?
Modified twin block
Springs or screw
Upper sectional fixed appliance
341
What is the aim of camouflage in class II div II?
Accept the underlying skeletal base relationship
Treat to class I incisor relationship
342
What class II div II patients are suitable for camouflage?
Mild to moderate class II skeletal pattern Growing
343
What is the aim of fixed appliances in class II div II?
Overbite reduction
Correction of inter-incisal angle (reduction)
344
How is inter-incisal angle corrected in class II div II?
Palatal root torque upper incisors
Proclination of lower incisors
345
What is necessary for upper incisors torquing in class II div II?
Needs adequate cancellous bone palatal to upper incisors
Risk of root resorption
346
What class II div II patients are suitable for orthognathic surgery?
Too severe a malocclusion for orthodontics alone
Non-growing patients
Profile concern
347
What are the features in stability and retention of class II div II?
Difficult to treat
Future facial growth can affect stability
Rotated laterals and deep overbite can relapse
Long term bonded retention usually required
348
What are the benefits of orthodontics?
Improvement in:
Appearance (dental, facial)
Function
Dental health
349
What are the psychological benefits of orthodontics?
Correction may improve self esteem and psychological well being (difficult to measure)
Severe malocclusions affect facial attractiveness
People with unattractive faces perceived unfavourably
Impact on minor malocclusions is more variable and debatable
Quality of life is improved
350
What are the stereotypes associated with normal dental appearance compared to their peers?
More intelligent
More friendly
More desirable as a friend
Less aggressive
351
What are the benefits of orthodontics in regard to function?
Mastication
Speech
352
Which conditions when treated give the greatest improvement in function?
Large anterior open bites
Severe increased overjet
Marked reverse overjet
353
What are the benefits of orthodontics to the dental health?
Difficult to describe
Prevention of consequences
354
What are the consequences of impacted teeth?
Can cause resorption
Supernumerary teeth can prevent normal eruption
Can be associated with cyst formation
355
What are the consequences of OJ >6?
Risk of trauma to upper incisors increases with size of OJ
Worse with incompetent lips
356
What are the consequences of anterior cross bites?
Loss of Perio support
Tooth wear
357
What are the consequences of a posterior crossbite?
A significant displacement may lead to: asymmetry, requiring early correction
358
What are the consequences of a posterior crossbite?
A significant displacement may lead to:
359
What is the association between crowding and caries?
Not directly linked
Caries to do with diet and fluoride
Crowded dentitions are harder to clean
360
What is the association between crowding and periodontal disease?
Weak association
Crowding can make cleaning more difficult
Individual motivation rather than tooth alignment has a bigger impact on
Importance of OHI
361
What are the consequences of deep traumatic overbites?
Gingival stripping
Loss of Perio support
362
Should orthodontics be provided to treat TMJ dysfunction?
Weak evidence of benefit/no guarantee
363
What are the risks of trauma?
Decalcification
Root resorption
Relapse
Soft Tissue trauma
Recession
Loss of periodontal support
Headgear injuries
Enamel fracture and tooth wear
Loss of vitality
Allergy
Poor/failed tx
364
What is the sequelae to orthodontic related decalcification?
Weakens the enamel to caries
Unusual staining
Frank cavitation
Gross caries
365
What are the four components to preventing decalcification?
Case selection
Oral Hygiene
Diet advice
Fluoride
366
What are the components of good case selection?
Motivated patient
Good OH pre-treatment
Low caries risk
High risk of decalcification indicated by: caries history, pre-existing decalcification, erosion
If low or borderline need- avoid tx
367
What are the components of good case selection?
Motivated patient
Good OH pre-treatment
Low caries risk
High risk of decalcification indicated by: caries history, pre-existing decalcification, erosion
If low or borderline need- avoid to
368
What is the OHI for orthodontic patients?
Minimum 2x day
After every meal
Disclosing tablets
Target gingival margins and around each bracket
369
What dietary advice should be given to orthodontic patients?
Encourage low Cariogenic diet
Decrease sugar intake frequency
Sugar free gum- stimulates salivary barrier
370
What fluoride should be offered to ortho patients?
Toothpaste
Mouthwash
Duraphat varnish
Fluoride releasing GIC
371
When should fluoride mouthwash be used?
In between brushing not after
372
What are the features of orthodontic related root resorption?
Inevitable consequence of tooth movement
1mm over 2 years fixed appliances
Most commonly UI>LI>6s
Mostly unnoticed but severe in 1-5%
373
What are the risk factors for root resorption?
Types of tooth movement: prolonged, high force, intusive movements, large movements, torque
Root form: blunt, pipette, resorbed already
Previous trauma
Nail biting
374
What is relapse?
The return of the features of the original malocclusion following correction
375
What teeth are particularly prone to relapse?
Lower incisors
376
What malalignments are most prone to relapse?
Crowding
Rotations
Instanding lateral
Spaces and diastema’s
Class II div 2
Anterior open bites
Reduced Perio support/short roots
377
What are the features of relapse management?
Case selection
Informed consent
Retainers- fixed, removable
378
What are the types of removable retainers?
Clear occlusal retainer
Pressure or vacuum formed (PFRs/VFRs)
Essix
Hawley types
379
What are the benefits of removable appliances?
Remove for OH
Can wear part time
Patient control
Easy to spot problem
380
What are the features of fixed retainers?
Prone to plaque and calculus build up
Can break and not notice
Need excellent OH
Tend to leave in situ for life
Require more care/long term maintainance
381
How should ortho related pain/discomfort be managed?
Analgesics
382
How should ortho related recession be managed?
Correct tx planning - teeth within bone, avoid over expansion
Thin biotype
Warn patient
Gingival graft
383
What is the impact of periodontal disease in regard to ortho treatment?
Accelerates alveolar bone loss and Perio destruction
384
What are the safety mechanisms of headgear?
2 minimum
Snap away traction spring
Nitom face bow
Masel strap
385
What is the association of orthodontics and tooth wear/ enamel fracture?
Tooth vs bracket
Greater risk with ceramic brackets as ceramic is harder than enamel
Enamel may fracture during debonding
386
What is the association between orthodontics and loss of vitality?
Rare
Increased risk if previous trauma or compromised tooth
Warn patient Gingival
Discolouration or darkened
387
What are the orthodontic associated allergies?
Latex, Nickel, Adhesive (colophony)
388
What is the clinicians role in poor/failed treatment?
Poor diagnosis
Poor treatment planning
Operator technique error- poor mechanics
389
What is the patients role in poor/failed treatment?
Unfavourable growth
Poor cooperation- with appliance wear, repeated breakages, poor attendance
390
What does orthodontic treatment success increase with?
Severity of malocclusion
Motivation of patient
Operator experience
391
What is the definition of hypodontia?
Congenital absence of one or more teeth
392
What is the definition of anodontia?
Complete absence of teeth
393
What is the definition of severe hypodontia?
6 or more congenitally absent teeth
394
What is the approx prevalence of hypodontia?
6% excluding 8s (25% 8’s)
6.3% F, 4.6% M
0.9% primary dentition
395
What teeth are more commonly affected by hypodontia?
• Most affected (8’s), L5’s, U2’s, U5’s, lower incisors
396
What % of population have missing upper laterals?
1-2%
20% of all missing teeth
Associated with ectopic canines
397
What are the main types of aetiology of hypodontia?
Non-syndromic
Syndromic
Environmental
398
What are the main types of aetiology of hypodontia?
Non-syndromic
Syndromic
Environmental
399
Discuss the non-syndromic aetiology of hypodontia?
Mutations in at least 3 genes associated with missing teeth in non-syndromic hypodontia
Familial
Sporadic
400
Discuss the syndromic aetiology of hypodontia?
>100 craniofacial syndromes associated with hypodontia
Cleft lip and palate
Anhydrotic ectodermal dysplasia
401
Discuss the environmental aetiology of hypodontia?
Trauma
Radiotherapy/chemotherapy
402
Discuss the environmental aetiology of hypodontia?
Trauma
Radiotherapy/chemotherapy
403
How does hypodontia present?
Delayed or asymmetric eruption
Retained or infra-occluded deciduous teeth
Absent deciduous tooth
Tooth form
404
What are the problems associated with hypodontia?
Microdontia
Malformation of other teeth
Short root anomaly
Impaction
Delayed formation and/or delayed eruption of other teeth
Crowding and/or malposition of other teeth
Maxillary canine/first premolar transposition
Taurodontjsm
Enamel hypoplasia
Altered craniofacial growth
405
What are the potential problems associated with hypodontia?
Spacing
Drifting
Over-eruption
Aesthetic impairment
Functional problems
406
What are the potential problems associated with hypodontia?
Spacing
Drifting
Over-eruption
Aesthetic impairment
Functional problems
407
What is the hypodontia care pathway?
GDP recognition
Referral to specialist orthodontist in GDH
408
What are the features in the assessment and planning for hypodontia patients?
History
Extra-oral exam
Intra oral exam - ortho aspects, restorative aspects
Investigations
Problem lists
Defunitatuve plan
Retention/maintainance
409
What are the investigation options for hypodontia patients?
Study models
Planning models- keeling, diagnostic
Radiographs
Photographs
Conebeam CT
410
What are the options for hypodontia management?
To illustrate the management options for missing upper lateral incisors
To highlight the advantages and disadvantages of the main treatment approache s
411
What are the tx options for missing lateral incisors?
Accept
Restorative alone (RBb, implant, partial denture)
Ortho alone
Combines restorative and ortho
412
What should be considered when tx planning hypodontia patients?
Satisfies expected aesthetic objectives
Least invasive
Satisfies expected functional objectives (immediate and long term)
413
What are the factors affecting RBB for replacing missing lateral incisor in hypodontia case?
Better success with cantilever design
Ideal abutment is canine
Technique sensitive
Grade and experience of operator important
414
What are the advantages of RBB for the replacement of a missing lateral incisor?
Relatively simple
Do when young (complete tx)
Non-destructive
Can look goood
Place on semi permanent basis
415
What are the disadvantages of RBB for the replacement of a missing lateral incisor?
Failure rate
Appearance sometimes not good
Orthodontic retention needs are high
Unpredictable aesthetics
416
What are the key differences between RBB and implants?
Can’t do implant until growth has ceased (21)
Need minimum 7mm space
Root separation
Often need bone graft
Technically very demanding in aesthetic zone
Significant time needed
Significant cost
417
What are the options for space closure?
Simple space closure
Space closure plus
418
What are the benefits of space closure in patients with missing lateral incisors?
No prosthesis- relatively low maintainance
Good aesthetics with appropriate orthodontics and restorative techniques
Can be done at a young age
419
What are the keys to the successful management of hypodontia?
Inter-disciplinary team (joint appointment)
Joint assessment and treatment planning with precise aims
Joint collaboration at transitional stages of treatment
Follow up of treated cases
420
What are the keys to the successful management of hypodontia?
Inter-disciplinary team (joint appointment)
Joint assessment and treatment planning with precise aims
Joint collaboration at transitional stages of treatment
Follow up of treated cases
421
Which tooth is usually considered the most important in determining the age at which the bone graft is carried out?
Canine
422
At what age do we take a radiograph to assess a patient for alveolar bone grafting?
7
423
When treating class III malocclusion in a patient using a fixed rapid maxillary expansion device , the accompanying headgear needs to be worn for at least:
14 hours a day
424
What percentage of orthodontically treated teeth have been shown to demonstrate severe root resorption
1-5%
425
What risk or orthodontic treatment is now becoming more widely seen in the patient population?
Gingival recession
