The unerupted maxillary canine Flashcards
What is the prevalence of ectopic canines?
- Low prevalence but high
in risk for GDP - Prevalence 2%
What is the prevalence of ectopic canines bucally?
- 5 percent
Line of the arch?
34 percent
Palatal?
61 percent
What is the problem with ectopic canines?
Root resorption
Incidence using plane radiographs?
12 percent
Incidence of ectopic canines using CT?
48 percent
Incidence of ecoptic canines using CBCT?
67 percent
Why does root resorption occur?
- Crowding/shortening of arch length
- Adjacent lateral incisor missing or abnormal in shape or size
- Long path of eruption
- Palatal = genetic; buccal = inadequate arch space
Brin, Becker & Shavlav, 1986…
- 2,500 patients with ectopic canines
- 43% had absent or small lateral incisors
Study shows that?
- Length of the root more critical than
What should you do if the canine is
not palpable buccally at 9-10 years?
Check – bulge, inclination and
colour of adjacent teeth.
Palpate – for the canine crown
buccally and palatally,
check for mobility of the
2 and C.
Radiographs – (parallax) Presence
Position
Pathology
What is parallax?
Physics / General Physics)
an apparent change
in the position of an object resulting from a
change in position of the observer
The principle of parallax can be used
The position of parallax can be used
to determine
the position of an unerupted tooth relative to its
neighbours.
When do we use it?
Palpate for canines when a patient is 9-10 years old
Index of suspicion is raised if?
the pt has a
missing, or abnormally shaped lateral
incisor;
has spaced arches, or
if palpation
indicates an asymmetrical eruption pattern
Clinical signs of a palatally impacted canine?
- Delayed eruption of 3 or prolonged retention of
the C - Absence of normal labial 3 bulge or presence
of a palatal bulge in the 3 region. - Delayed eruption, distal tipping of migration of
the lateral incisor. - Loss of vitality and increased mobility of the central or lateral incisor
Why do we use it?
- Knowing the location of the ectopic canine
allows us to treatment plan more
accurately. - If not managed correctly an ectopic canine
may resorb the root of the adjacent
incisors. This may result in a medico-legal encounter
How do we do it?
Horizontal parallax?
2xIOPAs (at least 20 degrees of tube shift needed)
Anterior occlusal and IOPA
Vertical parallax
Anterior occlusal and OPT
IOPA and OPT
How do we interpret it?
Tube movement for vertical from OPT to anterior occlusal the beam moves up
Tube movement for horizontal from IOPA to anterior occlusal the beam moves up
Pal with and buccal against
Studies suggest that which paralax is most effective in locating palataly ectopic canines?
Percentages?
Horizontal (88 percent vs 69 percent with vertical)
What about buccal ectopic canines and paralax?
Same effectiveness in being located with horizontal and vertical (63 percent)
To conclude the Armstrong et al paper suggested what about. DPTs and horizontal paralax?
That DPTs shouldnt be used in the investigation of canine ectopic where radiographs that allow horizontal paralax should be taken
Power and short study suggests- extraction of the deciduous canine in attempt to realign the palatally ectopic canine…
Success rate (in crowded dentitions)
62 percent
