Disturbances In Numbers

Question 1

How much of the population has missing permanent teeth?

Answer 1

4%

Question 2

What is the most common missing teeth?

Answer 2

mandibular 2nd premolar (most common), maxillary lateral incisor, maxillary 2nd premolar

Question 3

What considerations should be taken into place with missing teeth?

Answer 3

• ankylosis below the plane of occlusion (aka loss of PDL and tooth stuck to bone so big consideration for ortho tx)
• infra occlusion
• root resorption

Question 4

What phase do we take documentation for diagnostics (x-rays)?

Answer 4

phase I

Question 5

When would a prosthetic replacement (bridge/implant) not be a first choice for tx of congenitally missing teeth?

Answer 5

when patient is growing

Question 6

What’s a good treatment option for missing max. laterals?

Answer 6

orthodontic repositioning of canines because they typically erupt mesially so need to push them distally to allow space for an implant

Question 7

What can we use instead of an implant that is cheaper?

Answer 7

bonded/Maryland bridge

Question 8

What are TADS? and how are they different than implants?

Answer 8

temporary anchorage devices

• will not integrate in the bone like implants do
• good solution for while the patient is growing

Question 9

What is an option other than an implant for missing maxillary lateral incisors?

Answer 9

canine substitution by orthodontic space closure

Question 10

What are things to consider for a canine substitution?

Answer 10

• class II relationship (upper teeth will be further froward than normal compared to lower teeth)
• esthetics because the canine is higher up on the gingiva

Question 11

What is the release measurement of the mandibular and maxillary second primary molar?

Answer 11

1.7 mm for mandibular
0.9 mm for maxillary
so if over 3.4mm= crowding and consider extracting premolars

Question 12

What is most common tooth to be removed if overcrowding?

Answer 12

premolars

Question 13

What is the mean infra occlusion @ 11-12 year olds with lower second primary molar?

Answer 13

0.47 mm

Question 14

T/F: if the primary molars present at age 20, it is a good prognosis for long-term retention.

Answer 14

true

Question 15

What % of 19-20 year olds showed no infra-occlusion with a lower second primary molar?

Answer 15

45%

this means that at around age 20, if there is no problems with the primary molar, then we shouldn’t have any problems with the tooth

Question 16

What are some considerations for supernumerary teeth in primary dentition?

Answer 16

• frequently fused
• extraction if interfering with eruption
• 30% of supernumerary teeth are succedaneous

Question 17

Which arch are supernumerary teeth most commonly found in permanent dentition?

Answer 17

maxilla (anterior)

Question 18

What are some considerations for multiple supernumerary teeth in permanent dentition?

Answer 18

• altered tooth morphology is common
• keep the most normal appearing tooth and reposition orthodontically
• sometimes just wait and watch if extracting can misplace normal teeth

Question 19

What a good indication for removal of a mesiodens?

Answer 19

• disruption of eruption for central incisors

Question 20

What are ways to determine if the extra tooth is located buccal or lingually?

Answer 20

first try to palpate
then try to use cone beam tomography
- if unable to do those, different angulation of periapical x-rays can help us determine which side it is located (SLOB rule)

Question 21

If taking angling the X-ray tube on the same side as the tooth shows up on, it is? (mesial positioning, mesial tooth)
a. lingual
b. buccal

Answer 21

a. lingual

Question 22

If taking angling the X-ray tube on the opposite side as the tooth shows up on, it is?
(mesial positioning, distal tooth)
a. lingual
b. buccal

Answer 22

b. buccal

Question 23

What is the angling technique of periapical radiographs called?

Answer 23

SLOB rule