Orthodontic Classification, Terminology and IOTN

Question 1

What questions in family history are specific to an ortho patient?

Answer 1

Does the family have any similar dental problems?

• Eg) Missing teeth or Skeletal III

Previous history of orthodontic treatment in the family?

• Shows attitudes and compliance towards ortho

Question 2

What are some questions about past dental history you may ask an orthodontic patient? (3)

Answer 2

1. Have they had any treatment in the past such as extractions
2. Have they had any past trauma
3. Any digit sucking habits

Question 3

Define A-P Skeletal Patterns:

• I
• II
• III

Answer 3

I = Normal relationship

II = Mandible relatively retrusive (behind upper jaw)

III = Mandible relatively protrusive (infront of upper jaw)

(Class III can appear to look completely flat from chin to top of lip)

Question 4

Name these two lines of the image

Answer 4

Going across - Frankfurt plane

Going down - Zero Meridian line

Question 5

What are the 3 components of a skeletal relationship that we need to assess?

Answer 5

Anteroposterior (A-P)

Vertical

Transverse

Question 6

Assess these patients Frankfort Mandibular Planes Angle (FMPA)

Answer 6

1. High angle (Lines cross in front of the occiput)
2. Average angle (Lines cross at occiput)
3. Low angle (Lines cross behind occiput)

Question 7

When assessing the lips, if they are deemed incompetent what does this mean?

Answer 7

Lips do not meet at rest

Question 8

At rest when you lift the patient’s upper lip where should the lower lip cover until?

Answer 8

Cover lower third of upper incisior

Question 9

Describe the lip morphology of these 3 patients

Answer 9

1. Normal Lips
2. Thin Lips
3. Full Lips

Question 10

How can a skeletal II relation in a patient lead to lip incompetence?

Answer 10

The mandible is so far back in a patient that the lips meeting at rest causes to much strain on the patient

Question 11

What is the line in this picture?

Answer 11

Ricket’s E-Line

This can help show if a patients lips are protrusive or retrusive of this line

Question 12

What does this image display?

Answer 12

Incisal Display

Question 13

What are the 3 components of a dental arch assessment?

Answer 13

1. Alignment of teeth (any rotations)
2. Spaces or Crowding
3. The inclination of the teeth

Question 14

What are the 3 ways teeth can be inclined?

Answer 14

Normal

Proclined

Retroclined

Question 15

When giving a measurement of crowding in mm’s what are you refering to?

Answer 15

How much space is there missing for all the teeth to be in line

Question 16

How many mm’s is considered

1. Mild crowding
2. Moderate crowding
3. Severe crowding

Answer 16

1. <4mm
2. 4-8mm
3. >8mm

Question 17

How do you classify spacing in your notes?

Answer 17

Spacing can be either generalised or localised

Question 18

Describe a normal inclination of incisors

Answer 18

The crown of the tooth is more buccal (anterior) than the root

Question 19

Describe what you can see in this image clinically

Answer 19

Proclined incisor

Question 20

Describe what you can see in this image clinically

Answer 20

Retroclined incisor

Question 21

Describe the different classes of incisor relationships based on the relation between lower incisors to palatal aspect of upper incisors

1. Class I
2. Class II
3. Class III

Answer 21

1. Occlude at cingulum plateua
2. Occlude posteriorly to cingulum plateua
3. Occlude anteriorly to cingulum plateua

Question 22

What type of incisor relationship is this?

Answer 22

Class I

Question 23

What type of incisor relationship is this?

Answer 23

Class II division 1:

Incisal edges of the mandibular incisors occlude palatal to the cingulum plateau of the upper incisors. The maxillary incisors are proclined. There is usually an increased overjet.

Question 24

What type of incisor relationship is this?

Answer 24

Class II division 2:

The incisal edges of the mandibular incisors occlude palatal to the cingulum plateau of the upper incisors. The upper incisors are retroclined.

Question 25

What type of incisor relationship is this?

Answer 25

Class III: The incisal edge of the mandibular incisors occlude anterior to the cingulum plateau of the upper incisors.

Question 26

What is overjet?

Answer 26

Horizontal distance between incisal edge of upper incisors and labial face of lower incisors

Question 27

What is overbite?

Answer 27

Vertical overlap of lower incisors by upper incisors

Question 28

What is the red line showing?

Answer 28

Overjet

Question 29

What is the red line showing?

Answer 29

Overbite

Question 30

Describe where you would see the upper incisors overlap the lower inscisors for 1. A normal overbite 2. A reduced overbite 3. A increased overbite

Answer 30

1. Normal: in middle 1/3rd of lower incisor 2. Reduced: in incisal 1/3rd 3. Increased: in gingival 1/3rd

Question 31

Describe: 1. A class I molar relationship 2. A class II molar relationship 3. A class III molar relationship

Answer 31

1. Class I: Mesio-buccal cusp of maxillary first molar occludes in the mid-buccal groove of the mandibular first molar 2. Class II: Maxillary first molar occludes mesial to class I position 3. Class III: Maxillary first molar occludes distal to class I position

Question 32

Describe clinically what you see

Answer 32

Class I molar relationship

Question 33

Describe clinically what you see

Answer 33

Class II molar relationship

Question 34

Describe clinically what you see

Answer 34

Class III molar relationship

Question 35

In order to see if a patient can receive orthodontic treatment they must be judged againts the dental health component using the abreviation MOCDO What does MOCDO standfor

Answer 35

* Missing teeth (impacted teeth) * Overjet (\>+6mm;\>-3.5mm) * Crossbites (displacements \>2mm) * Displacement of contact points (\>4mm) * Overbite with trauma

Question 36

What are the two components needed for the Index of Orthodontic Treatment Need (IOTN)?

Answer 36

Dental Health Compnent Aestethic Component