Interceptive orthodontics Flashcards
What is the orthodontic timetable?
Primary dentition
Early-mixed dentition
Late-mixed dentition
Permanent dentition
When is the best time for orthodontic treatment?
early permanent dentition
What is the primary dentition, when established?
Established by 30 months
Positive overjet and overbite
Spacing normal
When is delayed eruption important?
When contralateral side different
abnormal sequence eruption
What are the primary dentition problems?
Delayed eruption Missing teeth Supernumary teeth Abnormal teeth Crowding Overjet Class III Crossbite Caries/trauma Habits
Does missing primary mean will get missing permanent?
can indicate this, but not always
Affects less than 1% of population
When are supernumerary teeth a worry?
What is the percentage that will have primary then permanent supernumerary
If causing displacement of other teeth
30-35% of patients will then get permanent
When do abnormal teeth need treatment
When displacing the permanent tooth
What is a fusion tooth?
2 teeth fused together - have 2 roots
What is a germinated tooth?
One tooth, one root, looks large
Why would you want to extract abnormal teeth?
To allow alignment of single permanent tooth
How much spacing is needed in the primary dentition for there to be enough space in the permanent dentition?
> 6mm spacing
If have an overjet in the primary dentition what does that mean for permanent?
Will probably be greater in the permanent dentition
Don’t do treatment at primary stage
Are crossbites in primary usually in permanent too?
Skeletal crossbites - tend to persist
Dental crossbites - variable
When may you want to treat crossbite?
If causing displacement between ICP and RCP
What is the problem with trauma to the primary tooth?
Possible ankylosis
Look out for deflection of permanent successor
Get dilaceration
What can habits cause in the primary dentition?
Anterior open bite
Unilateral crossbite
No intervention at this stage - not a problem till permanent teeth through
What is leeway space? What does this allow?
The mesio-distal width of the C,D,E are wider than the 3,4,5 underneath Common to have 1st molars in 1/2 unit class II, the leeway space allows the molars to drift mesially into class I
What is the leeway space in the lower and upper arch?
Lower = 2.5mm Upper = 1.5mm
What is the size discrepancy between primary and permanent incisors?
Upper 7mm greater when permanent
Lower 5mm greater
Permanent also more proclined to give more space
Lower, mandible grows to create space
If have delayed eruption what do you need to check?
No trauma
Dilacerated incisor
Most common cause midline = supernumerary teeth that needs to be removed
How would you treat an erupted mesiodens?
Extract and align
How would you treat an unerupted supernumerary mesiodens preventing incisors from erupting?
Need to remove via surgery XGA
What is a supplemental tooth? How do you treat it?
Looks exactly the same as the tooth next to it
Extract as most are poorly formed or displaced
If have premature loss of a C and D what can this cause
Shift in centreline to the side that had C or D removed
What happens if have premature loss of E?
Mesial movement of 6’s, uses up the space needed for the 5’s
Space loss greater and faster in the upper arch
In the upper arch, mesial movement/rotation of 6’s results in the 5’s being excluded palatally
What needs to be dont if extract a C and D to prevent loss of centreline
balance the extraction
Why don’t you balance the loss of E’s?
Disrupts occlusion
Can be unpredictable effect and doesn’t change the centre line
Would you compensate in the primary dentition?
No, if 6’s then would compensate
What are the problems with space maintainers?
Patient’s are often unsuitable for appliances
Must fit immediately
Often unnecessary
What are the causes of a midline diastema in the early-mixed dentition stage?
Normal - ugly ducklin stage 21/12 distally inclines because of the position of the canine crowns
Supernumerary tooth
Generalised spacing
Proclined upper incisors: Class II div I from digit sucking
Trauma
Pathology
What would you do if have an increased overjet in the early mixed dentition?
No advantage to treatment in the mixed dentition
Decide whether to treat now or wait - may want to treat early if lips are really incompetent
How could crowding be treated in the early mixed dentition? (not actually done)
Transverse expansion in lower arch relapses
Extract primary teeth -B’s or C’s but this just moves the crowding to premolar area
What are the indications for extraction of primary canines?
Permit local incisors to align Allow incisor to be moved over the bite Potentially to improve the position of palatally displaced permanent canines Severe upper and lower crowding Upper laterals palatal/impacted
How would you treat posterior crossbite in the early mixed dentition?
Consider treating early if have mandibular displacement on closure
Correct with URA
How would you correct the posterior crossbite
URA:
Midline screw
Adam’s cribs on 6’s 0.7mm diameter SS (retention and anchorage)
Acrylic baseplate (anchorage)
In the early mixed dentition what should be done about habit?
Educate patient and parents cessation of the habit
What can be done if patient has class III in early mixed dentition?
URA
Suitable for some class III aged 8-10 years old
Refer to an orthodontic specialist
Screw to expand the upper arch, wear for 14 hours a day
What are the problems faced in the late mixed dentition
Missing teeth Infraoccluded teeth Crowding Poor quality 6's Ectopic canines Habits
What needs to be done if have infraoccluded teeth?
Monitor then extract under LA
What can be done if have ectopic canines in the late mixed dentition?
Refer at time of diagnosis
Screen every year old patient for palpation of maxillary canines buccally and radiographs
Refer to orthodontist if evidence of ectopic position
What is the effect of habits in the late mixed dentition?
Proclined upper incisors
Anterior open bite
Unilateral posterior cross-bite
Increased overjet
When can you get better spontaneous correction of occlusion with digit sucking?
when stop before 8 years old
What removable appliance can be used for patients that digit suck?
Hayrake passive removable appliance - for correction of anterior openbite
wear 3 months full-time and 3 months night time only
It works by getting in the way every time patient tries to suck thumb
If have an overjet in late mixed dentition what can be done to treat?
Funcitonal appliances best during adolescent growth spurt 11-13 years
need something to put crib on - 4’s
What are the problems with adult treatment?
Lack of growth
Multilated dentition determining extraction patterns, reduced perio support for retention, perio disease
Co-operation can be difficult - ability to attend
Different expectations
Can’t have any active disease, no bleeding on probing, more uncomfortable
