13- included canines

Characteristics of an included canine and its frequency in upper vs lower vs locations?

Retained after period of eruption (9-13 yrs) despite having fully formed root

0.90% upper, 0.35% lower

50-80%- palatal, 15-30%- Buccal, 15-20%- intermediate

How can included canines be classified according to their position?

Horizontal plane- palatal, Buccal, intermediate

Sagital- upper, leveled or lower to adjacent apex

Frontal- vertical if less than 45 degrees, horizontal if over, angulated at 45

How can you classify an included canine according to their grade of inclusion?

Complete- no eruption

Intraosseous- crown and follicle fully covered by bone

Subgingival- crown emerges through bone covered by fibromucosa

Partial- some degree of eruption 

What are some predisposing factors of included canines?

Evolutionary- arch teeth discrepancy

Anatomical- has longest and complex eruption path 

Mechanics- physical obstacles 

What are general vs local etiological factors leading to included canine?

General syndromes and diseases- hypothyroidism, crouzon disease, cleidocranial dysplasia

Vs

Germ- Malformation, loss of eruption potential

Environment- missing lat incisor, varying size or root formation, supernumerary teeth, cysts, tumours

What are most frequent clinical signs of an included canine?

If perm canine absent or temp still present above 13-14 yrs

Effects fit of unstable prosthesis 

Linked to alopecia 

Palpation of hard bulge in palate

Mechanical manifestation of included canine

Displacement or rotation of adjacent teeth- especially lateral incisor

Root reabsorption

What are causes vs consequences of infectious problems associated with included canines?

Pericoronal or adjacent infections- may cause odontogenic cellulitis, palatal abscess, maxillary sinusitis 

How can you diagnose an included canine?

Panoramic

Cranium lateral teleradiography

CBCT 

Occlusal x rays

Periapical

What are the 2 types of occlusal radiographs?

Modified Simpson- beam perpendicular to sensor and parallel to incisors axis

Belot’s method- not perpendicular, palatal canines appear palatal but Buccal can be either

What is Clark’s positioning rule when considering periapical x rays?

Objects located in palate move in the same direction as the beam when two consecutive radiographs are obtained, the first centered and the second mesially or distally oriented

SLOB- sam lingual, opposite Buccal

What are the 3 general treatments for an included canine?

Therapeutic abstention- asymptomatic

Extract 

Reposition in arch- combine surgery and ortho techniques

Anesthesia and incision for upper canine in palatal position

Infraorbital, nasopalatine, anterior palate from corresponding side

Scalloped from mesial 2nd molar to mesial lateral incisor of opp side OR from premolar to premolar

When an upper canine is in a palatal position- flap, ostectomy, extraction, wound review, flap

Full thickness mucoperiosteal flap

Expose crown and neck

Luxation- consider odontosection of crown

Curettage, rinse with saline and make bony borders regular

Reposition flap and suture 

When an upper canine is in buccal position- anesthesia and incision 

Infraorbital, nasopalatine, medium palatine from corresponding side

Bilateral- Newman from 1.5 to 2.5 with vertical relieving incisions 

Unilateral- partial Newman from same side central incisor to dusta; 2nd premolar- M/D relieving incision 

When an upper canine is in a buccal position- flap, ostectomy, extraction, wound review, flap

Full thickness mucoperiosteal flap

Expose crown and neck

What is the most frequent scenario of upper canines in mixed position?

Crown in palatable, root Buccal

Palatal- extract crown

Buccal- locate apex- ostectomy, lúxate towards palate or buccal

Lower canine in buccal position- anaesthesia and incision 

IAN

Newman or semilunar 

Lower canine in lingual position

If possible- extract from Buccal- difficult access, risk of damaging structures in mouth floor 

If too lingual- linear lingual incision and pocket flap 

Lower canine in mixed psition

Odontosection

Remove crown and root separately 

What factors relating to surgical intervention should be considered before repositioning in arch?

Canine position and orientation 

Angulation- avoid if over 45 degrees

State of tooth, periocoronal sack, ligament and apex 

What is the purpose, indication and technique for conductive alveolotomy?

help eruption by exposing the crown after removing any obstacle

Canines in a favorable position that still have eruptive potential

A buccal or palatal flap is raised from the root area toward the desired canine position, ostectomy exposes crown, tooth can erupt naturally

What is the purpose, indication and technique for fenestration?

Fully expose the crown and cement it to an orthodontic button for traction- pull tooth into position 
Canines in an unfavorable position with no eruptive potential

How do you conduct extra mucosal fenestration in buccal vs palatal canines?

Buccal canines- similar to conductive alveolotomy, but flap is repositioned apically, suturing the attached gingiva around the neck 

Palatal- remove mucosa to expose canine 

How do you conduct intra/submucosal fenestration?

Full thickness triangular flap 

Cement orthodontic button, place ligature

Reposition flap and suture

What is translation and when is it indicated?

Controlled mobilization of canine within the bone, maintains vascularization and vitality

Buccally impacted canines

Two-thirds of the root already formed

Apex in normal position

Crown mesially angulated

What is the technique for translation?

Crown and 2/3 of the root are freed from the surrounding bone

A new bone cavity is created distal to the canine and mesial to the first premolar

Canine is mobilized into this new position, aligning it within the arch

What is transplant?

Extraction canine and place into a prepared socket in correct position- loses og vascularisation

What are some possible intraoperative complications?

Perforation of palatal fibromucosa

Apex fracture

Injury to roots of neighboring teeth

Perforate maxillary sinus or nasal cavity

Injury to the nasopalatine or mental bundles

Postoperative complications?

Infection

Necrosis of palatal fibromucosa (from poor blood supply)

Palatal hematoma

Suture dehiscence (stitches opening)

Abnormal mobility of adjacent teeth (from trauma during surgery)