Management of palatally ectopic canines Flashcards
The maxillary canine is second in its frequency of impaction with a prevalence of 1.5%. What tooth is the first?
mandibular 3rd molar
What position do ectopic canines occur most frequently in?
Palatally (85%)
they occur with twice the frequency that they occur buccally (15%)
The cause of ectopic canines are likely to be ______ and ______ despite remaining unclear
polygenic and multifactorial
What kinds of lateral incisors are palatally ectopic maxillary canines usually associated with?
- absent
- malformed
- diminutive (extremely small)
Assuming a normal eruption pattern, when should the majority of canines be palpable in the buccal sulcus?
by 10- 11 years
What is the approximate age of eruption of maxillary canines in girls?
12.3 years old
What is the approximate age of eruption for the maxillary canines in boys?
13.1 years old
What is the main risk of ectopic maxillary canines ?
resorption of the maxillary permanent incisors
CBT has detected root resorption in % of permanent lateral incisors adjacent to ectopic maxillary canines.
66.7%
When has it been postulated that root resorption due to ectopic canines most frequently occurs?
between 11 and 12 years old
(rarely starts after the age of 14)
State other possible consequences of palatally ectopic canines
- root resorption of the coronal aspect of the root
- cystic changes
When should practitioners suspect ectopia of the canine?
- 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
What radiographic technique has been deemed reliable for localising unerupted canines?
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
What is a horizontal parallax technique?
it involves taking 2 radiographs at two different horizontal angles but with the same vertical angulation
State two ways in which you can achieve a horizontal parallax technique
- anterior occlusal and periapical
- two periapicals
What is the vertical parallax technique?
increasing the vertical angulation of the X-ray tube from 60-65% to 70-75%
State two ways you can achieve the vertical parallax technique
- anterior occlusal (70-75 degrees) and optical projection tomography (OPT)
- periapical and OPT
What is the current disadvantage to the use of computed tomography technology over the use of conventional radiograph?
it has a higher overall effective dose
What interceptive treatment option may result in improvement of the position of an ectopic canine?
extraction of deciduous canine may result in improvement of position in selected cases
What considerations should be made prior to extraction of deciduous canines to improve the position of an ectopic canine?
- patient should be aged between 10 and 13 - better results are reported in the absence of crowding
- the need to maintain space or create additional space required consideration
- if radiographic examination reveals no improvement of the ectopic canines position 12 months following extraction of deciduous canine, alternative treatments should be considered
When interceptive extraction of deciduous canine is contraindicated, what alternative treatment options are available?
- surgical exposure and orthodontic alignment
- surgical removal of palatally ectopic canine
- transplantation
- no active treatment/leave and observe
What considerations must be made for surgical exposure and orthodontic alignment of a palatally ectopic canine ?
- 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
Give examples of instances where the degree of malposition of palatally ectopic canines deters candidacy for orthodontic alignment
- close proximity to midline
- above apices of adjacent teet
- horizontal angulation
When should surgical removal of palatally ectopic permanent canines be considered as a treatment option?
- 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
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 ?
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
When are the best results of ectopic canine replacement of lateral incisor tooth achieved?
- when there is good contact between the lateral incisor and first premolar
What risk should be discussed for surgical removal of palatally ectopic permanent canine?
risk of damage to the roots of adjacent teeth during the act of surgical removal
When is transplantation considered?
- 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
What are the requirements for transplantation?
- 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
What is the requirement for an RCT to be performed following transplantation of a canine tooth ?
- more than 3/4 of canine should be formed
When should the RCT following transplantation of a canine commence?
10 days following transplantation
When is no active treatment/leave and observe appropriate?
- 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
What is the frequency of radiographic monitoring of ectopic canines left in situ?
no current guidance available
The success of interceptive deciduous canine extraction declines as …
degree of malposition increases
When is clinical inspection and buccal palpation of the alveolus in the canine region recommended?
annually fromt the age of 8
Alongside interceptive extraction of deciduous canine, what increases successful permanent canine eruption?
Cervical pull headgear
What are the surgical techniques for surgical exposure of a palatally ectopic canine?
- open exposure technique
- closed exposure technique
Repeat surgery is more common with what type of surgical exposure technique?
closed exposure technique
The optimal time for surgical exposure and orthodontic alignment of ectopic canines is during…
adolescence
In cases where the first premolar is moved forward orthodontically to simulate canine, how can aesthetics be improved?
- mesio-palatal angulation of premolar
- placement of buccal root torque
- grinding of palatal cusp (to make less visible?)
What methods can be implemented to improve long term results of transplantation of canines?
- meticulous atraumatic surgical technique
- stabilisation of transplanted tooth with a sectional archwire for six weeks
