Impacted Maxillary Canines

Question 1

Give the definition of an impacted upper canine.

Answer 1

A canine that is prevented from erupting into its normal position by bone, tooth or fibrous tissue.

Question 2

What is the incidence of impacted maxillary canines?

Answer 2

3%

Question 3

What % of impacted canines are palatally positioned?

Answer 3

61%

Question 4

What % of impacted canines are positioned I’m the line of the arch?

Answer 4

34%

Question 5

What % of impacted canines are bucally positioned?

Answer 5

4.5%

Question 6

At what age should you be able to palpate a maxillary canine?

Answer 6

10 years

Question 7

At what age should a maxillary canine erupt into the mouth?

Answer 7

11-12 years

Question 8

What is the aetiology of impacted maxillary canines?

Answer 8

1. Long path of eruption.
2. Small or developmentally absent lateral incisors.
3. Crowding.
4. Genetics.

Question 9

What are the signs that a patient may have an impacted maxillary canine?

Answer 9

1. No mobility of the upper C.
2. Canine not palpable in baccalaureate sulcus by age 10.
3. Absence of a normal buccal bulge.
4. Presence of a palatal bulge in the upper 3 region.
5. Contralateral upper 3 erupted for more than 6 months.
6. Distal tipping or migration of the lateral incisor.
7. Loss of vitality or increased mobility in the lateral/central incisor.

Question 10

A 10 year old patient presents with a retained URC, how would you investigate the presence of the canine?

Answer 10

1. Observe - bulge, inclination and colour or adjacent teeth.
2. Palpation - of canine crown in the sulcus, mobility of the C and lateral.
3. Radiographs - to establish Presence, Position, Pathology. Use vertical or horizontal parallax to localise. Or CBCT.

Question 11

What is Parallax?

Answer 11

The relative movement of an object in relation to its surroundings when two images are taken of it from different angles. With radiography there must be a minimum tube head shift of 20°.

Question 12

What is the acronym associated with the parallax technique? Explain its meaning.

Answer 12

S.L.O.B

Stands for Same Lingual, Opposite Buccal. In the two radiography taken if the tooth appears to move in the same direction as the tube head then the tooth is lingually/palatally positioned. If the tooth appears to move in the opposite direction to the tube head then the tooth is bucally positioned.

Question 13

What are the types of parallax? Give examples.

Answer 13

1. Vertical: Dental Panoramic Tomograph (DPT) and standard upper occlusal (USO)
2. Horizontal: Dental Panoramic Tomograph (DPT) and Periapical (PA)

Question 14

What are the general treatment options for an ectopic canine?

Answer 14

1. No active treatment - monitor for root resorption and cyst formation.
2. Interceptive treatment - XT of UC’s age 10-13 in uncrowded mouths
3. Exposure and ortho - open exposure with copack dressing so eyelet can be bonded in practice / closed exposure bonding of gold chain string surgery.
4. Surgical removal.