Orthodontic Assessment Flashcards
when do we carry out orthodontic assessment? (4)
Ages 9: brief examination
11-12: Comprehensive examination when canines are premolars erupt
When older patients first come to you (if never been before)
If malocclusion develops in later life
what is an ideal occlusion based on?
Andrews 6 keys
list Andrew’s 6’s keys
Molar relationship Crown angulation Crown inclination No rotations No spaces Flat occlusal planes
teeth must all be the correct size
define the ideal molar relationship in relation to Andrew’s 6 keys.
The distal surface of the distobuccal cusp on the upper 1st permanent molar occludes with the medial surface of the mesiobuccal cusp if the lower 2nd molar.
define malocclusion.
More significant deviations from the ideal occlusion. May be considered as unsatisfactory aesthetically or functionally.
what are contraindicators to orthodontic treatment?
Allergy to Ni or latex
Epilepsy and the drugs used to control it
Some medications
Problems with imaging i.e. radiographs
when carrying out an orthodontic assessment what is important to note from their past dental history?
Frequency of attendance
Nature of previous treatment
Co-operation of previous treatment
Trauma to the dentition
when carrying out an orthodontic assessment what is important to note from their social history?
Habits: Thumb sucking Lower lip sucking Tongue thrust Chewing nails (can cause root resorption)
when carrying out an extra-oral examination which head position should the patient be in?
looking straight ahead with their frankfort plan parallel to the floor.
what should be examined in an extra-oral examination during orthodontic assessment?
Skeletal bases
Soft tissues
TMJ
what is it important to compare the patient to when carrying out an orthodontic assessment?
Compare the patient to their parent (especially class III)
look for Malocclusion
Growth potential
what 3 skeletal planes do we examine in a patient?
Antero-postero
Vertical
Transverse
how do we position the patient when examine the skeletal relationship? (3)
Patient can either be standing or seated
Ensure the Frankfort plane is horizontal to the floor = the superior border of the EAM to the lower border of the orbit
Or get the patient to look into their own eyes in the mirror which is a distance away
define a class I antero-postero skeletal pattern.
Maxilla 2-3mm in front of the mandible
define a class II antero-postero skeletal pattern.
Maxilla is > 3mm in front of the mandible)
These patients are retronathic: DONT have a small mandible it’s just further back on the skeletal base
define a class III antero-postero skeletal pattern.
Mandible is in front of the maxilla (maxilla is less than 2-3mm infront)
how do we assess the vertical skeletal pattern clinically ? (2)
We use the FMPA
- normal angle is 27 +/- 4
LAFH:TAFH - lower anterior face height to total AFH ratio
describe how the line from the frankfort plane and the mandibular plane interact in normal vertical skeletal patterns.
converge at the back of the head
normal angle is 27 +/- 4 degrees
describe how the line from the frankfort plane and the mandibular plane interact in increased vertical skeletal patterns.
lines meet way before the back of the head around the ear - Patient will have an AOB
long face angle is 31 degrees