Orthodontics

Question 1

Name 4 fluoride supplements you would give to a patient to prevent decalcification, naming dose and frequency.

Answer 1

Fluoride toothpaste - depending on age, 1450ppm, 2800ppm (under 16); 5000ppm (16+)

Fluoride varnish - 22,600ppm 4x annually

Fluoride tablets - 1mg 1x daily

Fluoride MW - 225ppm 1x daily

Question 2

Other than fluoride supplements, what are ways to prevent decalcification from orthodontic treatment?

Answer 2

OHI - teach toothbrushing technique/interdental cleaning beneath wires/around brackets 2x daily and after meals

Diet advice - avoid sugary items, encourage to eat them with meals, best to drink water between meals

Fissure sealants

Regular hygiene appts at GDP

Question 3

List 8 potential risks of orthodontic treatment other than decalcification.

Answer 3

Root resorption
Relapse
Wear of adjacent teeth
Loss of periodontal support
Loss of vitality
Gingival recession
Ulceration
TMJD

Question 4

How would you assess a patients skeletal AP relationship?

Answer 4

Visually - Frankfort plane parallel to the ground

Clinically (Palpation) - FP parallel to ground and palpate soft tissue point A and B

Lateral Cephalogram - SNA-SNB = ANB

Question 5

What are the classes of AP relationship?

Answer 5

Class I - Maxilla sits 2-3mm anterior to the mandible (ANB - 2-4 degrees)

Class II - Maxilla sits >2-3mm anterior of the mandible (ANB equal or more than 4 degrees)

Class III = Mandible in front of maxilla (ANB =-2)

Question 6

Name 4 special investigation an orthodontist may carry out when considering treatment?

Answer 6

Radiograph - OPT; Lateral Ceph
Clinical photos
Study models
Sensibility testing

Question 7

Describe a Class III incisor relationship

Answer 7

Lower incisors edges occlude anteriorly to the cingulum plateau of the upper central incisors

The OJ may be reduced or reversed

Question 8

Name 4 I/O features a patient may present with when they have a class III incisor maloclussion

Answer 8

Proclined upper incisors, retroclined lower incisors

Reverse OJ with anterior and posterior buccal crossbite

May have an OB

Maxilla often crowded with mandible aligned or spaced

Question 9

What systemic condition may a patient have if his mandible keeps growing?

Answer 9

Acromegaly

Question 10

How is a class III malocclusion managed?

Answer 10

Accept and monitor in mild cases where the patient has no concerns

Intercept early with URAs for correction of incisor relationship and anterior crossbite

Growth modification - Functional appliance (reverse twin block/Frankel III), chin cup, head gear with RME to reduce and redirect mandibular growth and encourage maxillary growth

Camouflage - accept underlying skeletal relationship and correct incisors to class I

Combined orthognathic and orthodontic treatment for functional, mastication or profile concerns

Question 11

Pt attends with anterior crossbite involving 21

When is the best time to begin treatment?

Answer 11

Intercept as soon as it is detected with URA

Question 12

Patient attends with anterior crossbite involving 21

What 3 features of the malocclusion would make it amenable to treatment with a URA?

Answer 12

Tooth in crossbite palatally tipped
Good overbite - aids stability
Adequate space to move the teeth forwards

Question 13

Design a URA for fixing an anterior crossbite involving 21

Answer 13

A - z spring on 11 0.5mm HSSW
R - adams clasps 16, 26 - 0.7mm HSSW
URD, ULD - 0.6mm HSSW
A - Yes
B - Self cure PMMA with posterior bite plane

Question 14

Define hypodontia

Answer 14

The congenital absence of one or more teeth excluding the 8s

It can be associated with microdontia and generally affects the lower 5’s, upper 2’s and upper 5’s

Seen more in females

Question 15

How is hypodontia diagnosed?

Answer 15

OPT Radiograph coupled with clinical examination

Question 16

What are 3 syndromes associated with hypodontia?

Answer 16

Cleft-lip-palate
Downs syndrome
Ectodermal dysplasia

Question 17

How may hypodontia present to you as a GDP?

Answer 17

Delayed or asymmetric eruption

Retained or infra-occluded deciduous teeth

Ectopic canines

Absence of deciduous teeth

Tooth malformation

Question 18

What are the treatment options for hypodontia?

Answer 18

Refer as soon as noticed - allocated to hypodontia clinic

Accept and monitor

Restorative alone - composite bonding, veneers

Orthodontics alone

Orthodontics and restoration - close space (simple or space closure plus) or open space (RBB; autotransplantation; implant; removable/fixed pros)

Question 19

Name 4 members of the MDT involved with hypodontia

Answer 19

Paediatric dentist
Orthodontist
Restorative dentist
Prosthodontist
Oral Surgeon
Speech/Language therapist
Clinical psychologist

Question 20

What 4 factors make early loss of primary teeth worse?

Answer 20

Age of the patient

If the arch is already crowded as there will be marked space loss in crowded patients

Losing Es - issues with permanent 6

If it occurs in maxilla as more space is lost in upper than lower

Question 21

When might you consider balancing a primary tooth extraction?

Answer 21

Balancing is the extraction of a tooth from the opposite side of the same arch

Balance Cs to prevent centre line drift in crowded arch

Consider balancing of lower Ds if arch is crowded`

Question 22

Give 4 reasons for an unerupted 1?

Answer 22

Supernumerary (usually tuberculate)

Trauma to A - dilaceration

Crowding

Pathology - dentigerous cyst

Question 23

What are your treatment options for an unerupted 1?

Answer 23

Surgical exposure with or without bonding using a gold chain

XLA of supernumerary if there is one present

Orthodontic traction used if over 9y

Fixed appliance use then bonded retainer

Question 24

What is the BSI classification of class II div I?

Answer 24

Lower incisor edges lie posterior to the cingulum of the upper incisors

OJ increased

Upper central incisors may be proclined or of average inclination

Question 25

What are the dental features in class II div I patients?

Answer 25

Proclined upper incisors
Increased OJ
Class 2 molars and canines

Question 26

What soft tissue problems are associated with Class II div I malocclusions?

Answer 26

Often incompetent lips due to prominence of upper incisors and/or underlying skeletal pattern

Inability to achieve anterior oral seal

May have lip trap and tongue thrusts