Ortho Digital Workflow

Question 1

What are the 5 main applications of the digital intra-oral scan in orthodontics?

Answer 1

Indirect bonding

lingual appliances

clear aligners

orthognathic surgical planning

retainer production.

Question 2

What is indirect orthodontic bonding?

Answer 2

Brackets are positioned virtually on a scanned model by a technician, then transferred to the teeth via a custom bonding tray for precise placement.

Question 3

What is CBCT data used for in indirect bonding?

Answer 3

Overlaid onto the digital scan to incorporate the patient’s actual root shape, aiding more accurate bracket positioning.

Question 4

What is the workflow for lingual appliances?

Answer 4

Intra-oral scan → diagnostic set-up with customised brackets designed for lingual surfaces → brackets manufactured → inserted into a transfer tray for bonding.

Question 5

What are the 3 categories of clear aligner therapy on the market?

Answer 5

Minor tooth movement aligners

Complex comprehensive systems (CAD/CAM)

Direct-to-consumer aligners.

Question 6

Why are orthodontists concerned about direct-to-consumer aligners? (4 reasons)

Answer 6

No pre-treatment dental fitness check

No full orthodontic assessment

Patients not informed of alternatives/risks

Supervised treatment risks harmful outcomes.

Question 7

How do aligners physically move teeth?

Answer 7

Through a mismatch between the aligner’s fitting surface and current tooth position — elastic deformation creates pressure on the tooth surface (“shape-moulding effect”).

Question 8

What are the most readily achievable tooth movements with aligners, and what movements require attachments?

Answer 8

Tipping and pushing are readily achievable.

More complex movements (torque, rotation, extrusion) require composite attachments bonded to the enamel.

Question 9

What is “loss of tracking”?

Answer 9

Loss of fit between the aligner and the teeth, indicating planned tooth movement has not been achieved.

Question 10

List 5 advantages of aligner treatment

Answer 10

Aesthetics; removable for eating and cleaning

Patient comfort

Reduced chairside time

Prediction software aids patient discussion

Possibility of remote monitoring.

Question 11

Who holds clinical responsibility for the aligner treatment plan?

Answer 11

The prescribing clinician/dentist — full responsibility rests with them regardless of technician input.

Question 12

What must a lab prescription include?

Answer 12

Aims of treatment; which teeth to move/accept; teeth that cannot have attachments; any overcorrections required; teeth to be extracted.

Question 13

What biological factors does the digital diagnostic set-up fail to account for?

Answer 13

Gingival biotype, alveolar bone width and height, pulp chamber size, soft tissue factors affecting post-treatment stability.

Question 14

What materials are aligners commonly made from?

Answer 14

PET, PETG, and TPU. Direct 3D printed aligners use biocompatible epoxy resins and photopolymers.

Question 15

List 5 factors affecting the biomechanics of an aligner.

Answer 15

Material type; thickness (0.5–1.5mm)

Physical properties: oral environment degradation;

Manufacturing method

Periphery extension

Presence of attachments

Question 16

What are the 4 main adjuncts used in aligner systems?

Answer 16

Composite attachments; IPR (interproximal reduction); features built into the aligner (e.g. bite ramps, power ridges); metal buttons and intermaxillary elastics.

Question 17

What are the 4 main problems when using aligners for premolar extraction cases?

Answer 17

Excessive tipping adjacent to extraction sites; development of lateral open bites; poor incisor torque control; anchorage loss.

Question 18

What tooth movements does Aligner therapy struggle with?

Answer 18

Rotational control
Mesio-distal tipping
Root torque
Extrusion
Intrusion

Question 19

What are the main reasons predicted tooth movements may not be achieved?

Answer 19

Patient non-compliance (less than 22+ hours/day wear)

Loss of tracking from over-ambitious movements

Inaccurate attachment placement

Insufficient IPR or aligner retention.

Question 20

What does post-operative stability evidence show for aligners?

Answer 20

Relapse is greater with aligner treatment than fixed appliances

Question 21

What were the most common issues in aligner complaints (Dental Complaints Service 2024)?

Answer 21

Misdiagnosis, inadequate treatment planning, lack of informed consent, poor management of patient expectations. Anecdotally 70–80% of orthodontic complaints relate to aligner therapy.

Question 22

CAT

Answer 22

clear aligner therapy