ortho Flashcards
Impacted Tooth
A tooth that fails to erupt in the dental arch in the expected time.
Ectopic Tooth
Malpositioning due to abnormal eruption path.
Which tooth is most commonly impacted?
Lower 3rd Molar
(followed by maxillary canines)
4 common reasons for impacted canines:
- local hard tissue obstruction
- local pathology
- abnormal incisor development
- genetics
5 Potential Reasons for Impaction:
- lack of space
- develops in abnormal position
- obstruction from another tooth/cyst/tumours
- excessive soft
- genetic
At what age should canines be palpated / assessed?
9
What should you do if you cannot palpate upper canines by the age of 10?
Establish the 3 Ps:
P reserve
P osition (radiographs, SLOB)
P athology (resorption)
SLOB rule
S ame
L ingual
O pposite
B uccal
(if the unerupted tooth is not seen to move with the tube then it is likely that it lies in the line of the arch)
5 Treatment Options for Impacted Canines
- leave it
- interceptive tx - extract primary.
- surgical exposure and alignment
- surgical auto transplantation
- extraction
Eruption Age for Upper Canines
11-12
Eruption Age for Lower Canines
9-10
When to be concerned about tooth eruption:
If it has not erupted within 6 months of its contralateral tooth.
or
If it doesn’t erupt at all within usual eruption dates.
IOTN for impacted canines
5i
Orthognoathic Surgery
Correction of function and aesthetic consequences of severe dentofacial deformity through ortho + surgery.
When should you ideally undertake orthognathic surgery?
When growth is complete.
(avoids outgrowing surgical correction)
What is the ANB for a Class I Skeletal Base?
2-4º
What is the ANB for a Class II Skeletal Base?
> 4º
What is the ANB for a Class III Skeletal Base?
<2º
Archwire
Fastened to all of the brackets and creates force to move teeth into proper alignment.
Brackets
Directly bonded onto teeth to hold the archwire in place.
Metal Band
Ring of metal often used in place of buccal tubes when greater strength is required.
Ligature
Holds the archwire to the bracket.
(either a rubber band or twisted wire)
Elastic Hooks and Rubber Bands
Elastic hooks used for attachments of rubber bands, helping teeth move toward their position.
What occlusion does headgear correct?
class II
Which class is corrected by attaching bands from an upper 6 to a lower 3?
class III
What class is being corrected when attaching bands from the lower 3 to upper 6?
Class II
What type of anchorage do elastic bands provide in ortho?
reciprocal
