Management of palatally ectopic canines Flashcards

1
Q

The maxillary canine is second in its frequency of impaction with a prevalence of 1.5%. What tooth is the first?

A

mandibular 3rd molar

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2
Q

What position do ectopic canines occur most frequently in?

A

Palatally (85%)

they occur with twice the frequency that they occur buccally (15%)

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3
Q

The cause of ectopic canines are likely to be ______ and ______ despite remaining unclear

A

polygenic and multifactorial

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4
Q

What kinds of lateral incisors are palatally ectopic maxillary canines usually associated with?

A
  • absent
  • malformed
  • diminutive (extremely small)
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5
Q

Assuming a normal eruption pattern, when should the majority of canines be palpable in the buccal sulcus?

A

by 10- 11 years

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6
Q

What is the approximate age of eruption of maxillary canines in girls?

A

12.3 years old

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7
Q

What is the approximate age of eruption for the maxillary canines in boys?

A

13.1 years old

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8
Q

What is the main risk of ectopic maxillary canines ?

A

resorption of the maxillary permanent incisors

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9
Q

CBT has detected root resorption in % of permanent lateral incisors adjacent to ectopic maxillary canines.

A

66.7%

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10
Q

When has it been postulated that root resorption due to ectopic canines most frequently occurs?

A

between 11 and 12 years old

(rarely starts after the age of 14)

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11
Q

State other possible consequences of palatally ectopic canines

A
  • root resorption of the coronal aspect of the root
  • cystic changes
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12
Q

When should practitioners suspect ectopia of the canine?

A
  • if it is not palpable in the buccal sulcus by the ages of 10-11 years
  • if palpation indicates assymmetrical eruption pattern
  • if adjacent teeth implies malposition of the permanent canine
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13
Q

What radiographic technique has been deemed reliable for localising unerupted canines?

A

horizontal parallax

(deemed more reliable than vertical parallax in this instance)

However, more recently, computed tomography technology has become available for imaging maxillofacial region and can be used for localisation of impacted teeth

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14
Q

What is a horizontal parallax technique?

A

it involves taking 2 radiographs at two different horizontal angles but with the same vertical angulation

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15
Q

State two ways in which you can achieve a horizontal parallax technique

A
  • anterior occlusal and periapical
  • two periapicals
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16
Q

What is the vertical parallax technique?

A

increasing the vertical angulation of the X-ray tube from 60-65% to 70-75%

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17
Q

State two ways you can achieve the vertical parallax technique

A
  • anterior occlusal (70-75 degrees) and optical projection tomography (OPT)
  • periapical and OPT
18
Q

What is the current disadvantage to the use of computed tomography technology over the use of conventional radiograph?

A

it has a higher overall effective dose

19
Q

What interceptive treatment option may result in improvement of the position of an ectopic canine?

A

extraction of deciduous canine may result in improvement of position in selected cases

20
Q

What considerations should be made prior to extraction of deciduous canines to improve the position of an ectopic canine?

A
  1. patient should be aged between 10 and 13 - better results are reported in the absence of crowding
  2. the need to maintain space or create additional space required consideration
  3. if radiographic examination reveals no improvement of the ectopic canines position 12 months following extraction of deciduous canine, alternative treatments should be considered
21
Q

When interceptive extraction of deciduous canine is contraindicated, what alternative treatment options are available?

A
  • surgical exposure and orthodontic alignment
  • surgical removal of palatally ectopic canine
  • transplantation
  • no active treatment/leave and observe
22
Q

What considerations must be made for surgical exposure and orthodontic alignment of a palatally ectopic canine ?

A
  • patient should be willing to wear fixed orthodontic appliance
  • patient should be motivated and have good OH
  • degree of malposition should not be so great that orthodontic alignment is impractical
23
Q

Give examples of instances where the degree of malposition of palatally ectopic canines deters candidacy for orthodontic alignment

A
  • close proximity to midline
  • above apices of adjacent teet
  • horizontal angulation
24
Q

When should surgical removal of palatally ectopic permanent canines be considered as a treatment option?

A
  • if patient declines active treatment
  • if patient is happy with their dental experience
  • if there is radiographic evidence of early root resorption of adjacent incisor teeth
  • if canine is severely malpositioned
  • when alignmend and transplantation are not being considered
  • in cases where there are pathological changes
  • in cases where retention would impede otthodontic appliance use
25
Q

Although surgical removal of ectopic permanent canine is indicated where there is early root resorption of lateral incisor, when is this treatment plan not suitable ?

A

in cases where there is severe root resorption of the incisor tooth.

Here the incisor tooth would be extracted instead of the ectopic permanent canine

The permanent canine is then used to fill the space

26
Q

When are the best results of ectopic canine replacement of lateral incisor tooth achieved?

A
  • when there is good contact between the lateral incisor and first premolar
27
Q

What risk should be discussed for surgical removal of palatally ectopic permanent canine?

A

risk of damage to the roots of adjacent teeth during the act of surgical removal

28
Q

When is transplantation considered?

A
  • other possible active or interceptive treatment has failed or inappropriate
  • patient unwilling to wear orthodontic appliance
  • degree of malposition of canine is too great for orthodontic treatment to be practical
29
Q

What are the requirements for transplantation?

A
  • adequate space available
  • sufficient alveolar bone
  • prognosis of canine tooth to be transplanted is good with no evidence of ankylosis
  • RCT (depends on stage of root formation of the transplanted tooth)

to accept transplanted tooth

30
Q

What is the requirement for an RCT to be performed following transplantation of a canine tooth ?

A
  • more than 3/4 of canine should be formed
31
Q

When should the RCT following transplantation of a canine commence?

A

10 days following transplantation

32
Q

When is no active treatment/leave and observe appropriate?

A
  • pt does not want treatement/happy with appearance
  • no evidence of root resorption of adjacent teeth or other pathology
  • good contact between lateral incisor and first premolar
  • deciduous canine should have good prognosis
  • no pathology associated; particularly if canine is remote from dentition; ectopic canine can be left in situ
33
Q

What is the frequency of radiographic monitoring of ectopic canines left in situ?

A

no current guidance available

34
Q

The success of interceptive deciduous canine extraction declines as …

A

degree of malposition increases

35
Q

When is clinical inspection and buccal palpation of the alveolus in the canine region recommended?

A

annually fromt the age of 8

36
Q

Alongside interceptive extraction of deciduous canine, what increases successful permanent canine eruption?

A

Cervical pull headgear

37
Q

What are the surgical techniques for surgical exposure of a palatally ectopic canine?

A
  • open exposure technique
  • closed exposure technique
38
Q

Repeat surgery is more common with what type of surgical exposure technique?

A

closed exposure technique

39
Q

The optimal time for surgical exposure and orthodontic alignment of ectopic canines is during…

A

adolescence

40
Q

In cases where the first premolar is moved forward orthodontically to simulate canine, how can aesthetics be improved?

A
  • mesio-palatal angulation of premolar
  • placement of buccal root torque
  • grinding of palatal cusp (to make less visible?)
41
Q

What methods can be implemented to improve long term results of transplantation of canines?

A
  • meticulous atraumatic surgical technique
  • stabilisation of transplanted tooth with a sectional archwire for six weeks