Risks And Benefits Of Ortho

Question 1

What does MOCDO stand for?

Answer 1

Missing teeth
Overjet
Cross bite
Displacement of contact points
Overbite

Question 2

What are some risks with impacted teeth?

Answer 2

Can cause root resorption of adjacent teeth, supernumeraries can prevent normal eruption, can be associated with cyst formation.

Question 3

What are the risks associated with anterior cross bite?

Answer 3

Gingival stripping of lower anteriors
Mobility of lower anteriors

Question 4

What are some problems with posterior cross bites
?

Answer 4

May lead to asymmetry

Question 5

What are some risks with crowded teeth?

Answer 5

Caries and perio risk as more difficult to clean

Question 6

What are risks associated with overbite?

Answer 6

Gingival stripping/ loss of perio support of lower incisors.

Question 7

What are the main 4 risks of ortho?

Answer 7

Decalcification
Root resorption
Relapse
Soft tissue trauma

Question 8

What are the less common risks of ortho treatment?

Answer 8

Recession
Loss of perio support
Enamel fracture and toothwear
Poor/ failed treatment

Question 9

What is de calcification and how is it prevented?

Answer 9

Decalcification occurs around the brackets causing white squares/ cavitation.
Prevention:
Case selection - motivated patient
OH - must be very good
Diet - avoid fizzy drinks, high frequency of sugar etc
Fluoride - high fluoride toothpaste, mouthwash etc

Question 10

What is the incidence of root resorption with ortho?

Answer 10

It is an inevitable consequence of tooth movement - approx 1mm over 2 years with fixed appliances.
Severe in 1-5% of cases

Question 11

Which teeth are mostly affected by root resorption?

Answer 11

Teeth that are used for anchorage / experience bodily movements

Upper and lower incisors
6s

Question 12

What are the risk factors for root resorption?

Answer 12

Prolonged treatment
High forces
Intrusion
Large movements
Torque
Previous trauma
Blunt roots

Question 13

What features are most prone to relapse?

Answer 13

Lower incisor crowding
Rotations
In standing 2s
Spaces and diastema’s
Class 2 div 2
Anterior open bite
Reduced perio support/ short roots

Question 14

How is relapse prevented?

Answer 14

Fixed or removable retainer

Question 15

What is the average root resorption experienced?

Answer 15

1mm over 2 years

Question 16

What is severe root resorption and its prevelence?

Answer 16

1-5% experience severe root resorption
>4mm

Question 17

What type of root resorption is caused by ortho?

Answer 17

External surface

Question 18

What is root resorption?

Answer 18

Non bacterial destruction of dental hard and soft tissue due to the interaction of clastic cells

Question 19

What are the symptoms of ESR?

Answer 19

Usually asymptomatic until forces become so strong, apical blood supple is disturbed

If severe - mobility

Question 20

How does orthodontic force cause root resorption?

Answer 20

Orthodontic force causes compression of the PDL which results in hyalinisation and inflammation.
This activates osteoclasts which remove hyaline material and remove superficial cementum.
This results in root resorption

Question 21

How does ortho cause recession?

Answer 21

Inflammation and tooth movement stresses the limits of biology.

Question 22

How long does the PDL take to remodel?

Answer 22

8 months

Question 23

What is pericision?

Answer 23

Treatment for rotated teeth.
Teeth will still be remodelling when ortho stops, therefore supracrestal fibres will be twisted after correction of rotation.
Severe these supracrestal fibres (down to alveolar bone) to prevent rotation relapse

Question 24

How long does it take for each component of pdl to remodel?

Answer 24

1 month for bone
3-4 months for collagen fibres
6 months for gingival fibres
up to 12 moths for supracrestal fibres to remodel.

Question 25

What are the benefits of ortho?

Answer 25

Psychological benefits
Function - mastication and speech
Denial health benefits