Orthodontic Competancies Flashcards
What does ANB indicate?
Soft tissue A point, to soft tissue B point via the nasion.
Increased indicates skeletal class II
Decreased indicates skeletal class III
How is LAFH calculated?
Ratio of Glabella subnasale and menton
50/50 clinically
55/45 ceph
What does SNA indicate?
Relative AP development of the maxilla to the cranial base.
Decreased indicates maxillary retrognathisism
Increased indicates maxillary prognathisism
What does SNB indicate?
Relative AP development of the mandible to the cranial base.
Decreased indicates mandibular retrognathisism
Increased indicates mandibular prognathisism
What does FMPA angle tell you?
Angle of lower mandible border to Frankfort plane
Increased indicates a more class II relationship
Decreased a more class III
What does MMPA angle tell you?
It can give you an indication as to which way the face is growing, and the relationship between the maxilla and mandible.
A decreased one may indicate decreased LAFH and an increased may indicate and increased one.
What is the average naso-labial angle?
100 degrees
What habbits should we be aware of?
Digit sucking (AOB, Pro Ui, Ret Li, narrow upper arch, uni-lateral crossbite)
Lip sucking ( Ret Li, irritation to labial tissues)
Nail biting (linked to root resorption)
What are the components of MOCDO?
Missing teeth
Overjet
Crossbites
Displacement
Overbite
Outline what should be on the problem list?
Skeletal pattern
Mandibular/maxillary growth
Soft tissue problems (lip trap, incompetant lips)
MODCO problems
Dental problems (spacing, diastema etc.)
Classification of class I incisors?
Lower incisal edges occlude to cingulum plateu of upper incisors.
Classification of class IId1 incisors?
Lower incisal edges occluse posterior to cingulum plateu of upper incisors
Uppers are proclined or average, there is an increase in overjet.
Classification of class IId2 incisors?
Lower incisal edges occlude posterior to cingulum plateu of upper incisors
Uppers are retroclined, there is a reducded but increases in overjet.
Classification of class III incisors?
Lower incisal edges occlude anterior to cingulum plateu of the upper incisors.
There is a reduced or reversed overjet.
What is the average coverage of an overbite?
Covers 1/2 to 1/3 of lower incisor crowns.
How can you tell if an overbite is complete or not?
Incisors will occlude in complete.
How do you determine the midline of a patients face?
Glabella to subnasale
What are the degrees of crowding?
Mild - 2 to 4mm
Moderate - 4 to 8mm
Severe - >8mm
Compare space required to space available
Overlap technique
What indications may there be to suspect hypodontia (before taking a radiograph)?
- Delayed or asymmetric eruption
- Retained or infraoccluded deciduous teeth
- Absent deciduous tooth (if no primary = no permanent)
- Tooth form
What are the main treatment options for orthodontics?
Accept
Growth modificaiton
Extractions only
Camouflage
Orthognathic surgery
What are Andrew’s six keys for orthodontic treatment?
Class 1 molars
Class 1 incisors
Tight contacts with no rotations
Flat occlusal plane or curve of spee
Long axis have slight mesial inclination
Crowns of the posteriors have lingual inclination
What are the main risks of orthodontics?
Treatment failure
Relapse
Gingival recession
Root resorption (1-2mm normal)
Decalcification
Which features have a high potnetial for relapse?
Rotations
Diastemas
AOB
Instanding U2s
Lower incisor crowding
How can you create space for orthodontics?
Extraction of teeth (4s and 5s typically)
Expansion of maxilla (RME or mid palatal screw)
Distalise buccal segment (fixed ortho)
Modifiy skeletal growth (twin block, headgear)
If a patient presents with an orthodontic emergency, what is the general procedure you should follow?
Ask how it happened
Account for missing components
Deal with problem
Account for retention
Refer to orthodontist
A patient presents with a URA, with a fractured southend clasp where the wire is emanating from the acrylic. What should you do?
Cut southend in the middle
Turn remainder back to create C clasp
Smooth rough edges
Check retention
Can’t soulder as too close to acrylic
A patient presents with a fixed bonded retainer, which has debonded from two teeth. The wire is still stable, what should you do?
Remove as much composite as possible around the two teeth.
Check tooth health
Check wire integrity
Rebond if all fine
A patient presents with a fixed appliance with molar bands. A bracket has come loose on the LR3, the archwire is stable, but the bracket can freely rotate. What should you do?
Potential risk of aspiration/ingestion
Remove the bracket by removing ligature
Keep archwire in place
Hand bracket to PT, and refer to orthodontist
A patient presents with a URA, with a fracture at the midpoint of the southend clasp. What should you do?
Bend both ends into c clasps
Can’t soulder as its an area of flex
A patient presents with a fixed bonded retainer, which has a fracture in the middle and is no longer passive. What should you do?
Remove as no longer fit for use
Check tooth health
Consider prescribing a new retainer
A patient presents with a fixed appliance with molar bands and a TPA. The TPA is fractured where it meets the band, what should you do? What is a TPA for?
A TPA is used mainly for anchorage
Can’t bend or solder
TPA not fit for purpose.
Remove TPA at other band, with irrigation, high volume aspiration, and a floss tie around it so you don’t drop it.
Smooth area
Refer to orthodontist
A patient presents with a URA, one of the adams clasps has fractured at both points where it leaves the acrylic. What should you do?
Account for missing component
Refer for chest X-ray if unsure
Smooth edges
If retentive then all good
If not then:
- Replace clasp
- Send lab prescription, working cast, and the appliance
- If OG cast lost, then take new impression with URA in. Cannot simply put on new cast as wont fit and will lead to creep during cure.
A patient presents with a fixed bonded appliance with molar bands. A bracket has come off. It is not freely rotating, and is secure with the ligature. What should you do?
Little risk of it coming off as it can’t rotate
Check its secure
Instruct patient to move bracket from side to side to clean
Refer to orthodontist
A patient presents with a URA that has shattered in their pocket. What should you do?
Do not attempt to wear
Do not super glue as cannot be repaired
Account for all the pieces
Offer thermoplastic retainer in meantime
Refer to orthodontist
A patient presents with archwire slippage on their fixed appliance. What should you do?
Remove excess wire on one side
Create retetentive tag on other side to prevent further slipage
Refer to orthodontist
A patient presents with a URA, with a fracture through the arrowhead of the clasp. What should you do?
Not an area of flex, and away from acrylic so can be soldered if equipment there.
If not remove all but the normal arrowhead, turning it into a c-clasp.
Check for retention, if not there then needs replacing.
A patient presents with a fixed appliance with molar bands. One of the bands has become loose. What should you do?
Do not cement on, may interfere with treatment.
Cut archwire mesially to band, create a retentive tag.
Tak eband off
Give to patient and refer to orthodontist.
A patient presents with a fixed bonded appliance, and has sustained a trauma. Multiple brackets have debonded, and there are ligatures missing. What should you do?
Account for the missing components.
Archwire likely not fit for purpose so remove.
Leave any bonded components in place.
Give all components to patient and refer back to orthodontist with trauma stamp.
Consider placing eax over brackets to smooth them off.
A patient presents with a fixed bonded retainer, which has debonded on one tooth. It has distorted slightly, and is pointed away from tooth. What should you do?
Would not want to rebond as would apply force to tooth.
Cut off that portion of retainer.
Refer for new retainer if its going to be a problem.
A patient presents with a URA, the adams clasp has fractured mesially where it eminates from the acrylic. What should you do?
Cut at distal arrowhead. Turn it into a C-clasp.
Check for retentionl. If not retentive enough then send to lab to get new component attached.
Requires appliance, prescription, and origional working cast.
