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

How would you assess the tongue in a soft tissue assessment?

Answer 13

Check the size of the tongue in relation to the oral cavity. It shouldn’t be too large, or too small.

The resting position should be:
- Constantly resting forward against the lower lip

Question 14

What are the 3 components of a dental arch assessment?

Answer 14

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

Question 15

What are the 3 ways teeth can be inclined?

Answer 15

Normal

Proclined

Retroclined

Question 16

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

Answer 16

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

Question 17

How many mm’s is considered

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

Answer 17

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

Question 18

How do you classify spacing in your notes?

Answer 18

Spacing can be either generalised or localised

Question 19

What is the dental term of a “gap”?

Answer 19

Maxillary median diastema

Question 20

Describe a normal inclination of incisors

Answer 20

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

Upper: 109 degrees (+/- 5 degrees) to the maxillary plane.
Lower: 93 degrees (+/- 6 degrees) to the maxillary plane.

Question 21

Describe what you can see in this image clinically

Answer 21

Proclined incisor

Question 22

Describe what you can see in this image clinically

Answer 22

Retroclined incisor

Question 23

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 23

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

Question 24

What type of incisor relationship is this?

Answer 24

Class I

Question 25

What type of incisor relationship is this?

Answer 25

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 26

What type of incisor relationship is this?

Answer 26

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 27

What type of incisor relationship is this?

Answer 27

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

Question 28

What is overjet?

Answer 28

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

Question 29

What is overbite?

Answer 29

Vertical overlap of lower incisors by upper incisors

Question 30

What is the red line showing?

Answer 30

Overjet

Question 31

What is the red line showing?

Answer 31

Overbite

Question 32

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 4. Anterior open bite 5. Complete/Incomplete

Answer 32

1. Normal: in middle 1/3rd of lower incisor 2. Reduced: in incisal 1/3rd 3. Increased: in gingival 1/3rd 4. NO vertical overlap 5. Contact with teeth or mucosa/no contact

Question 33

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

Answer 33

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 34

Describe clinically what you see

Answer 34

Class I molar relationship

Question 35

Describe clinically what you see

Answer 35

Class II molar relationship

Question 36

Describe clinically what you see

Answer 36

Class III molar relationship

Question 37

What is a crossbite?

Answer 37

Mandibular deviation between centric relation and centric occlusion. Upper teeth should occlude buccal to lower teeth.

Question 38

What are the types of crossbites?

Answer 38

Anterior or Posterior Unilateral or bilateral

Question 39

What type of crossbite does each image represent?

Answer 39

Question 40

What is the aetiology of malocclusion?

Answer 40

1. Genetic control (skeletal relations) 2. Environmental factors (soft tissues + dento-alveolar + habits)

Question 41

What are the aims of malocclusion treatment?

Answer 41

1. Facial: - Accept or address skeletal pattern 2. Dental: - Relieve dental crowding & align teeth - Reduce the overbite & overjet - Achieve class I incisor +/- molar relationship - Eliminate cross-bite & associated mandibular displacement - Retention.

Question 42

What are the 6 keys of an ideal occlusion?

Answer 42

1. Molar Relationship 2. Correct angulation 3. Correct inclination 4. No Rotations 5. No spacing 6. Flat curve of Spee

Question 44

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

Answer 44

1. The Dental Health Component - Grades 4 & 5 – definite need for Tx - Grade 3 – borderline need for Tx - Grades 1 & 2 – low need for Tx 2. Aesthetic Component - Grades 8-10 - definite need for Tx - Grades 5-7 - borderline need for Tx - Grades 1-4 - low need for Tx

Question 45

In order to see if a patient can receive orthodontic treatment they must be judged against the "dental health component" of the IOTN using the abbreviation MOCDO. What does MOCDO stand for?

Answer 45

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