Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Dentistry Module 7 > Orthodontics > Flashcards

Orthodontics Flashcards

1
Q

What important information needs to be gathered in a dental/social history as part of an orthodontic assessment?

A

Dental:
1. History of trauma
2. Ongoing or previous dental treatment
3. TMJ problems
4. Known inherited dental problems (e.g. hypodontia)
5. Previous orthodontic treatment

Social:
1. Habits (e.g. digit-sucking)
2. Patient motivation
3. Socio-behavioural factors

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

What habit might make an individual at increased risk of root resorption if they are planning to wear braces?

A

Nail biting, puts extra pressure/force on teeth.

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

What are the three planes that the face and dentition should be examined in as part of clinical orthodontic examination?

A
  1. Anteroposterior
  2. Vertical
  3. Transverse
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Describe the extra-oral anteroposterior assessment of a patient.

A

Maxilla to mandible relationship assessment (class I, II, or III)

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

Describe the 5 steps to an intra-oral anteroposterior assessment of a patient.

A
  1. Incisor classification
  2. Overjet
  3. Canine relationship
  4. Molar relationship
  5. Anterior crossbite
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Describe the 2 steps to an extra-oral vertical assessment of a patient.

A
  1. Facial thirds
  2. Angle of lower border of mandible to maxilla
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Describe the intra-oral vertical assessment of a patient.

A

Assess whether there is an overbite, anterior open bite, or lateral open bite.

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

Describe the extra-oral transverse assessment of a patient.

A

Facial asymmetry assessment

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

Describe the two steps to an intra-oral transverse assessment of a patient.

A
  1. Centrelines
  2. Posterior crossbite
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What true vertical line is used to estimate anteroposterior relationship?

A

Zero meridian line

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

In a class 1 relationship where should the upper lip and chin point lie in relation to the zero meridian line?

A

The upper lip should lie on or slightly anterior to the line

The chin point should lie slightly behind the line

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

Describe the relationship of the upper jaw to the lower jaw in a normal class I skeletal relationship.

A

The upper jaw lies 2-4mm in front of the lower

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

Describe the relationship of the upper jaw to the lower jaw in a class II skeletal relationship.

A

The lower jaw would be greater than 4mm behind the upper jaw

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Describe the relationship of the upper jaw to the lower jaw in a class III skeletal relationship.

A

The lower jaw is less than 2mm behind the upper jaw

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

Describe how to assess the angle between the lower border of the mandible and the maxilla on a clinical assessment to determine the vertical relationship of a patients face and dentition.

A

The mandibular plane angle can be estimated by the point of contact of intersecting lines, these intersecting lines are composed of the line of the lower border of the mandible, and the Frankfort horizontal plane.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

When is the mandibular plane angle in a vertical relationship assessment considered normal?

A

When the two lines intersect at the occipital (back of the head)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are the 4 features of the lip to assess in smile aesthetics relevant to orthodontic treatment?

A
  1. Lip competence
  2. Lip fullness
  3. Nasiolabial angle
  4. Method of achieving an anterior seal
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What does it mean if someone has lip competency?

A

The lips meet together at rest

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What does it mean if someone has lip incompetency?

A

The position of incisors prevents a comfortable lip seal from being maintained at rest, however the patient is able to hold lips together if required.

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

What is a normal value for the nasolabial angle?

A

90-110 degrees

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Why may some people with lip incompetency experience tongue thrusting?

A

In some people with lip incompetency, the tongue thrusts forwards to contact the lips so to achieve an anterior seal, as the lips are not able to do this on their own.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

How is overjet measured?

A

From the labial surface of the most prominent incisor to the same surface of the mandibular incisor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What would a normal overjet be?

A

2-4mm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

When is an overjet given a negative value?

A

In a situation where the lower incisor lies anterior to the upper incisor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What does overbite measure?
It measures how much the maxillary incisors overlap the mandibular incisors in a vertical direction.
26
What is a complete overbite?
Where the lower teeth are in contact with the opposing teeth or soft tissues
27
What is an incomplete overbite?
If the lower teeth are not touching anything
28
If there is no overlap of the upper incisor with the lower, what is this described as?
An anterior open bite
29
What is a crossbite?
“It is a discrepancy in the buccolingual relationship of the upper and lower teeth”
30
What causes displacement of the mandible on closure when someone has a crossbite?
Due to premature contact on specific teeth when the patient closes together, so this can lead to the mandible being repositioned.
31
When a patient has a crossbite, what position of the jaw should the orthodontic treatment plan be based on?
Retruded contact position
32
Describe a buccal crossbite.
Where the buccal cusps of the mandibular teeth occlude buccal to the buccal cusps of the maxillary teeth
33
Describe a lingual crossbite.
Where the buccal cusps of the mandibular teeth occlude lingual to the palatal cusps of the maxillary teeth
34
How is mild, moderate and severe crowding measured and what are the ranges?
Measured in mm. Mild = 0-4mm Moderate = 4-8mm Severe = >8mm
35
What type of malocclusion can cause TMJ issues?
Cross-bite with displacement of the mandible
36
What classification is used to describe molar relationship?
Angle’s classification
37
Describe Class 1 molar relationship.
“Where the mesiobuccal cusp of the upper first molar occludes with mesiobuccal groove of the lower first molar”
38
Describe class 2 molar relationship.
“ where the mesiobuccal cusp of the lower first molar occludes distal to the class 1 position”
39
Describe class 3 molar relationship.
“ where the mesiobuccal cusp of the lower first molar occludes mesial to the class 1 position”
40
What does IOTN stand for?
Index of Orthodontic Treatment Need
41
What does IOTN help determine?
The likely impact of a malocclusion on an individuals dental health and psychosocial well-being.
42
What is bimaxillary proclination?
Where the maxillary and mandibular incisors are proclined
43
What causes crowding of teeth?
1. A discrepancy between size of teeth and size of arches 2. Supernumerary teeth 3. Ectopic teeth 4. Retained teeth
44
What factors may cause late lower incisor crowding?
1. Forward growth of the mandible 2. soft tissue maturation 3. Mesial migration of posterior teeth 4. Third molar presence 5. Alteration of the original arch form with orthodontic treatment
45
What are the two main causes of generalised spacing?
1. Hypodontia 2. Small teeth in a well developed arch
46
What are the three main causes of localised spacing?
1. Hypodontia 2. Traumatic loss of a tooth 3. Extraction
47
Define an anterior open bite.
“Where there is no vertical overlap of the incisors when the buccal segment teeth are in occlusion.”
48
Define a posterior open bite.
“When the teeth are in occlusion there is space between the posterior teeth”
49
Define an incomplete overbite.
“where the lower incisors do not occlude with the opposing upper incisors or the palatal mucosa when the buccal segments teeth are in occlusion.”
50
Define a cross bite.
“ a discrepancy in the buccolingual relationship of the upper and lower teeth”
51
Define a buccal crossbite.
“ the buccal cusps of the lower teeth occlude buccal to the buccal cusps of the upper teeth”
52
Define a lingual crossbite.
“ the buccal cusps of the lower teeth occlude lingual to the lingual cusps of the upper teeth”
53
What is the most common local cause of a crossbite?
Crowding of teeth
54
Define a class 1 incisor relationship.
“ the lower incisor edges occlude with or lie immediately below the cingulum plateau of the upper central incisors” Ref-BSI
55
Define a class II div I incisor relationship.
“ the lower incisor edges lie posterior to the cingulum plateau of the upper incisors. There is an increase in overjet and the upper central incisors are usually proclined” Ref-BSI
56
What is the most common type of malocclusion treated in the western world?
Class II division I
57
What type of malocclusion puts an individual at increased risk of traumatic injury?
Class II div I
58
Define a class II div II incisor relationship.
““ the lower incisor edges occlude posterior to the cingulum plateau of the upper incisors and the upper central incisors are retroclined” Ref-BSI
59
Why is an increased overbite often seen in class II div II incisor relationships?
“Due to the lack of occlusal stop to limit eruption of the lower incisors”
60
Define a class III incisor relationship.
“ the lower incisor edges occlude anterior to the cingulum plateau of the upper incisors” Ref-BSI
61
Name 6 factors that are suggested as possible causes of maxillary canine displacement.
1. Displacement of the crypt 2. Long path of eruption 3. Short-rooted or absent upper lateral incisor 4. Crowding 5. Retention of the primary deciduous tooth 6. Genetic factors
62
What type of canine displacement is associated with missing or peg shaped lateral incisors?
Palatally displaced canines
63
What are the two things you are looking for clinically to estimate the likely locations of an unerupted maxillary canine?
1. Palpation 2. Inclination of lateral incisor
64
What are buccaly displaced canines usually associated with?
Crowding
65
Why are buccaly displaced canines more likely to erupt than palatally displaced canines?
Because of the thinner buccal mucosa and bone
66
In what 4 cases is surgical removal of the impacted canine considered?
1. Deciduous canine has acceptable appearance 2. Patient is happy with aesthetics of deciduous canine 3. Patient reluctant to embark on more complicated treatment. 4. If Impacted canine outwith range of orthodontic alignment
67
When is orthodontic alignment of an impacted canine considred to be very difficult?
1. If the crown tip of the impacted canine is at or above the apical third of the incisor root 2. If the canine crown us close to the midline of face (if more than halfway across upper central incisor) 3. If canine apex is distal to second premolar
68
What is meant by transposition?
Interchange in the position of two teeth
69
What types of parallax can be used to localise the position of an ectopic canine, and which combination of radiographic views are usually used for these?
Vertical parallax: DPT and anterior occlusal Horizontal parallax: DPT and PA, or PA and PA
70
When does development of permanent canines commence within the arch?
4-5 months of age
71
When does calcification of permanent canines occur?
6-7 years old
72
At what age do the upper canines erupt?
11-12 years old
73
At what age do lower canines erupt?
10-11 years old
74
At what age should a GDP palpate from canines, Palatally and buccaly?
Approx 8-9 years of age
75
At what age should canines definitely be palpable from?
11 years old
76
What 4 factors put an individual at higher risk of impacted canines?
1. Family history of impaction 2. Female 3. Class II div 2 4. Hypodontia/microdontia
77
What are the treatment options for managing an impacted canine?
1. Interceptive treatment (extraction of c’s) 2. Open exposure 3. Closed exposure 4. Surgical extraction
78
Describe the following landmark, Sella.
Midpoint of the sella turcica
79
Describe the following landmark, Nasion.
The most anterior point on the fronto-nasal suture
80
Define, the tip of the anterior process of the maxilla, situated at the lower margin of the nasal aperture.
The anterior nasal spine (ANS)
81
Define, the tip of the posterior nasal spine of the maxilla.
Posterior nasal spine (PNS)
82
On a cephalometric tracing of a radiograph, what is meant by the “A point”?
The point of deepest concavity on the anterior profile of the maxilla
83
Define, the most inferior point on the mandibular symphysis.
Menton
84
Define, the lowest point of the midline of the lower jaw.
Gnathion
85
Define the most anterior point of the mandibular symphysis.
Pogonion
86
Define the most posterior inferior point on the angle of the mandible.
Gonion
87
On a cephalometric tracing of a radiograph, what is meant by the “B point”?
The point of deepest concavity on the anterior surface of the mandibular symphysis
88
Define, the analysis and interpretation if standardised radiographs of the facial bones.
Cephalometrics
89
What are the 7 main landmarks to find and highlight on a cephalometric radiograph?
1. Sella 2. Nasion 3. ANS 4. PNS 5. A and B point 6. Gonion 7. Menton
90
What angle indicates the relative antero-posterior positioning of maxilla in relation to cranial base?
SNA angle
91
What is the average SNA angle, in degrees?
82 degrees
92
What angle indicates the antero-posterior positioning of the mandible in relation to the cranial base?
SNB angle
93
What is the average SNB angle in degrees?
80 degrees
94
What angle denotes the relative position of maxilla and mandible to each other?
ANB angle
95
What is the average ANB angle in degrees?
2 degrees
96
What skeletal pattern does an increased ANB angle indicate? (>4 degrees)
Class II
97
What skeletal pattern does a decreased ANB angle indicate? (<2 degrees)
Class III
98
What angle is formed by intersection of mandibular plane with maxillary plane?
Maxillo-mandibular plane angle (MMPA)
99
What useful information can cephalometric analysis provide for ortho treatment?
Assess: 1. Aetiology of malocclusion 2. Planning treatment
100
What is the purpose of IOTN?
To help determine the likely impact of malocclusion on an individuals dental health and psychosocial well-being.
101
What are the two components of IOTN?
1. Dental health component 2. Aesthetic component
102
How many grades of treatment need are there? And what do they indicate in terms of treatment required?
5 grades: 1+2: no or little need for Tx 3: borderline need 4+5: need treatment
103
Give four clinical examples of grade 5 scores for (IOTN) treatment need?
Large overjet Impacted teeth Cleft palate Submerged deciduous molar
104
What are the two aids to help with using IOTN?
1. Acronym MOCDO 2. IOTN ruler
105
What does the acronym MOCDO stand for?
M= missing teeth O= overjet C= crossbite D= displacement of contact point O= overbite
106
Why is MOCDO considered a hierarchical scale?
Only the most severe single worst occlusal trait is recorded (using the order of MOCDO)
107
Hypodontia is graded on the DHC of IOTN using terms 5h or 4h. What do these mean?
4h = one tooth in a quadrant missing 5h = two or more teeth in a quadrant missing
108
What DHC of IOTN grading is an overjet given if it is >9mm?
5a
109
What DHC of IOTN gradings can a reverse overjet be given?
- 5b if theres no difficulties with speech or mastication - 5m or 4m depending if there is speech or masticatory difficulty
110
What DHC of IOTN grading will an anterior crossbite or unilateral buccal crossbite with mandibular displacement >2mm be given?
4c
111
What DHC of IOTN grading will a scissors bite in one or both buccal segments be given?
4L
112
Describe what DHC of IOTN gradings differing lengths of contact point displacement will be given?
>4mm = 4d 2-4mm= 3d >1mm but <2mm= 2d
113
What IOTN gradings do most dental hospitals restrict orthodontic treatment to?
Grades 4 and 5
114
What are the IOTN requirements for NHS orthodontic treatment?
DHC grade 3 and AC >6
115
What is a class II intermediate incisor relationship?
Where one central incisor is retroclined and the other is proclined
116
List 3 main benefits of orthodontic treatment?
1. Improved fucntion 2. Improved aesthetics/psychological benefits 3. Less prone to incisal trauma
117
List 7 risks of orthodontic treatment.
1. Relapse 2. Treatment failure 3. Tooth resorption/root shortening 4. Enamel dimineralisation 5. Ankylosis 6. TMJ issues 7. Gingival damage
118
What does the aesthetic component of IOTN assess?
The aesthetic handicap posed by malocclusion and the likely psycho-social impact upon the patient.
119
True or false? IOTN can be used in both the permanent and primary dentition.
False, can only be used in permanent dentition
120
In the primary dentition, what are the 5 indications for referral to orthodontic specialists?
1. Severe skeletal discrepancies 2. Severely delayed dental development 3. Missing/supplemental teeth 4. History of head and neck radiotherapy +/- chemotherapy 5. Advice for balancing/compensating extractions
121
In the mixed dentition, what are the 9 indications for referral to orthodontic specialists?
1. Severe skeletal patterns (developing class II/III) 2. Dental anomalies 3. Developmentally missing permanent teeth 4. Supernumerary teeth 5. Teeth in unfavourable positions e.g. canines 6. Impacted first permanent molars 7. Infraoccluded teeth 8. Extraction advice where severe crowding evident or first molars have poor prognosis 9. Advice following trauma to permanent teeth
122
In the permanent dentition, what are the indications for referral to orthodontic specialists?
Clear cut IOTN grading (NHS if 3/6 and above, private if <3/6)

Dentistry Module 7 (14 decks)

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