Impacted Canines

Question 1

What is impacted tooth?

Answer 1

When a tooth is unable to erupt due to one or more of following:
Inadequate space in the arch
Ectopic position of the tooth in relation to where it would normally be expected
The presence of an obstruction such as retained tooth supernumerary or scar tissue/lesion

Mainly: maxillary canines that are either buccally or palatally placed
* Some evidence it is more palatally than buccally impacted

Question 2

Prevalence of impacted canines

Answer 2

Permanent maxillary canines are second most common teeth that are impacted after third molars
0.92-3% prevalence

Question 3

Aetiology of impacted maxillary canines

Answer 3

Unclear

Genetic theory: genetics is thought to influence the initial developmental position of the crypt and the subsequent eruptive path of the tooth

Guidance theory: postulates that the canine’s eruption into the dental arch relies on it being guided along the distal surface of lateral incisors. If the lateral incisor tooth is peg shaped or absent, the chances of impaction may be increased as canine cannot be positioned accurately in dental arch

Other factors:
Retained primary canine tooth
Presence of supernumerary
Scar tissue or crowding in dental qrch

Question 4

Clinical examination for impacted canines

Answer 4

Important to start buccal palpation of the alveolus in the canine region annually after pt is 8years old

Normally - canines should be palpable in the buccal sulcus at around 10 years of age
If not, suspecting there is a risk of impaction

If visual examination and palpation are insufficient, radiographs are indicated (usually after pt is 10 years of age as prior- little benefit of knowledge gained)- parallax technique

Question 5

Treatment options

Answer 5

No treatment+monitor- suitable is pt not keen for treatment, unsustainable for ortho due to poor OH, no evidence of resorption or devitalisation of adjacent teeth, no mobility or cystic changes; but risks need to be explained

Xla of primary canines- as it might allow normal eruption of palatally impacted canines; if xla: do it when pt is 10-13 , consider position of unerupted canine, absence of crowding

Surgical removal of impacted canines- if good contact between lateral incisor and first premolar; if not possible to achieve alignment of the impacted canine in the arch; is pt not keen or unsuitable for ortho treatment to allow alignment of impacted canine

Closed exposure: if canine deeply impacted; mucoperiosteal flap exposing tooth up to cingulum, gold ortho bracket bonded to the tooth, chain secured to adjacent tooth or to existing ortho appliance

Open exposure: if canine is superficial; same procedure but tooth is left exposed but covered with ribbon gauze for 1-2 weeks and then tooth can be added with the gold bracket if not done before and monitor it’s eruption