Week 8- Ortho Referrals

Question 1

What are important points of medical history from ortho perspective?

Answer 1

• Syndromes affecting craniofacial development
• Chronic upper airway obstruction (effects on facial development)
• Allergies
• Prev facial trauma
• High doses of drugs that interfere with bone turnover- prostaglandin inhibitors, bone resorption inhibiting meds for osteoporosis or arthritis (can impede tooth movement)

Question 2

What is important dental history to gather from ortho pt?

Answer 2

• Dental attendance
• Caries/restos
• Diet
• OH
• Dental trauma
• Missing teeth
• TMJ symptoms
• Bruxism
• Habits

Question 3

Where is facial midline?

Answer 3

A perpendicular line to the interpupillary line. The facial midline should pass through:
• Glabella
• Subnasale
• Philtrum of the upper lip
• Midline of the chin

Question 4

What are transverse facial proportions?

Answer 4

• Distance between the eyes should be the same as the width of the eye
• The nose and chin should be centered within the central fifth
• The width of the nose should be about the size of the central fifth
• Width of the lips should be the same as interpupillary width

Question 5

What are vertical facial proportions?

Answer 5

The face can be divided into three vertical regions which should be approximately the same size
• Upper third
• Middle third
• Lower third (can be further subdivided into the upper third and lower two thirds)

Question 6

How can VME be managed?

Answer 6

Orthognathic surgery

Question 7

Issue with this smile + tx?

Answer 7

Posterior vertical maxillary excess

• No issues with occlusion but would require orthognathic surgery

Question 8

What are buccal corridors?

Answer 8

Defined as the space between the buccal surfaces of the maxillary teeth and the corners of the mouth during smile. Small buccal corridors are more aesthetic.

Question 9

How can wide B corridors be managed?

Answer 9

• SME or RME as child
• If adult, would require SARPE (surgically assisted rapid palatal expansion)

Question 10

How can facial convexity be visualised?

Answer 10

This is visualised by lines connecting glabella, subnasale and soft tissue pogonion

Question 11

What is a limitation of angles classification?

Answer 11

Only focuses on molar class. Doesn’t indicate incisal relationship

• Molar relationship is class III but incisal relationship is class II in this pic

Question 12

What happens to gingival margin as teeth over erupt?

Answer 12

Gingival margin moves coronally (can lead to excess gingival display)

Question 13

What tx has been performed in this case?

Answer 13

Excess anterior gingival display. Anterior teeth intruded to correct gingival margin. Then restorative build up of incisal edges was carried out.

Question 14

Issues with pts features? + tx

Answer 14

• Asymmetry
• Excess gingival display
• Reasonable contour
• 21 gingival margin is lower than 11
• 11 is longer than 21
• Deep bite

Tx was intrusion of upper incisors (to reduce gingival display)- more intrusion of 21 is required than 11. 21 then required incisal build up.

Question 15

Identify issues + tx

Answer 15

• Midline shift
• Lateral open bite
• Posterior crossbite LHS

Mx expansion and then maryland bridge

Question 16

What do you need to put in ortho referral letters?

Answer 16

• Patient: name, DOB, address
• Clinical findings
• Provisional tx plan
• Next appt scheduled, med hx any other dental tx required.

Question 17

How to manage this case?

Answer 17

16 has over erupted so can’t restore space of 46. Would need to intrude 16 orthodontically

Question 18

What deviation from midline isn’t usually noticeable?

Answer 18

<2mm

Question 19

What can midline shift be caused by?

Answer 19

• Spaces
• Tooth rotations
• Missing teeth
• Incorrect tooth proportions

Question 20

What is an ideal anterior tooth display on smile?

Answer 20

100% incisal display and up to 2mm gingival (for adolescents). 75% incisal display in minimum for acceptable facial aesthetics

Question 21

What is the smile arc?

Answer 21

Curvature of mx incisal and canine edges. Smile arc should closely resemble the contour of lower lip (consonant smile)

Question 22

What factors contribute to smile arc?

Answer 22

• Length of mx teeth
• Inclination of mx incisors
• Occlusion plane angle
• Intrusion/extrusion of anterior teeth

Question 23

What are the goals of profile analysis?

Answer 23

• Establish whether jaws are positioned correctly in AP plane
• Evaluate md plane angle, lip posture and incisor prominence
• Re-evaluate facial proportions from frontal view

Question 24

What is facial convexity for class II vs class III patients?

Answer 24

Class II: convex

Class III: concave

Question 25

What are incompetent lips?

Answer 25

• When lips don’t meet at rest.
• If lips are incompetent, ask pt to bring lips together and observe if there is activation of circumoral muscles

Question 26

What is often associated with flat vs steep md plane angle?

Answer 26

• Steep: long facial type and tendency for open bite
• Flat: short facial pattern and tendency for deep bite (inc overbite)

Question 28

What is RCP?

Answer 28

Position the teeth initially contact when condyle is located in most anterior superior position in glenoid fossa

Question 29

What is intercuspal position?

Answer 29

Position of maximal intercuspation of teeth

Question 30

What is crowding/spacing a result of?

Answer 30

Discrepancy btwn tooth widths and size of dental arch

Question 31

Issues with this case?

Answer 31

• Deep overbite
• 13 is impacted so primary canine is over-retained. 23 has erupted (appears larger) and could lead to midline shift
• Pt has class I facial profile