W7 - Self-correcting Anomalies in Growing Dentition - Mani Flashcards
Synonym for Self-correcting anomalies? Do they require tx?
Transient malocclusion
- Do not require tx
How does the jaw appear from birth to eruption of 1st deciduous teeth?
Retrognathic mandible
- Upper gum pad protrudes about 5 mm
Causes of retrognathic mandible (3)
self-correcting anomaly
Growth magnitude and duration greater in anterior mx than anterior md
Upper anterior gum pad > lower anterior gum pad
Md does most its growth post-natally rather than pre-natally
When and how does retrognathic md correct itself?
SCA
6-7 months
- By downward and forward growth of the mandible
Features of SCA anterior open bite (3)
Upper and lower gum pads only contact at molar region
- Helps with suckling
- Considered normal
- Corrects at 6-7 months
When and how does SCA anterior open bite correct itself
6-7 months
- eruption of primary incisors
Self correcting anomalies of the predental period (3)
Anterior open bite
Retrognathic mandible
Infantile swallowing
Self correcting anomalies of the primary dentition (4)
All normal from 6mo - 3 years
Anterior deep bite
Flush terminal plane
Edge to edge bite
Spacing
is a LACK of space in primary dentition normal?
NO - indicates crowding in coming permanent dentition
Causes of anterior deep bite (3)
SCA
- Primary teeth more upright than successors
- More vertical inclination (150 degree inter-incisal angle)
- Infra occlusion of partially erupted molars
How does anterior deep bite correct itself (3)
SCA
Complete eruption of primary molars (increases VDO)
Attrition of incisal edges
Forward and downward growth of mandible
EXAM NOTE
Pictures may be shown of early dentition and ask or treatment → may just require observation as it is a self-correcting anomaly
3 types of spacing in the primary dentition
Primate spaces
Developmental / physiological spaces
Leeway
How does spacing correct itself in the primary dentition (2)
Eruption of perm
Eruption of first permanent molar (early mesial shift)
Why is leeway space important
Helps in establishing class 1 occlusion
(in addition to differential jaw growth)
How is edge to edge bite self corrected?
Eruption of permanent incisors
More labial inclination (inter-incisal inclined 123 degrees)
When does anterior deep bite need to be corrected?
Approx 10 years old
if earlier, do not correct → normal malocclusion
This is due to erption of large permanent incisors
How does anterior deep bite self correct?
By complete eruption of primary molars - increases the vertical dimension
What is the ugly-duckling stage aka Broadbent phenomenon?
Seen at 8-11 years old
Difference in dimension of primary and permanent teeth
front teeth look big bc theyre permanent
Midline diastema due to growing canines applying pressure onto the converging incisors roots
My childs smile is wack, big teeth, spacing. Fix it
Don’t touch - this is normal appearance and malocclusion
Ugly duckling phenomenon / Broadbent
Midline diastema due to erupting canines
Smile will correct itself once mx permanent canine erupts
Why does midline diastema form (9-10 years old)
Growing / erupting canines putting pressure on incisor roots
- Causes them to diverge
Self-correcting anomalies of the permanent dentition
not many
Increased overjet / overbite - however will not be corrected more than 1 mm by 20 years old
How to answer ortho based questions
Regardless of malocclusion
consider the age first
note**
Need to know the following for conditions (epillepsy, downs)
Oral manifestations of the actual condition
Oral manifestation as a result of medication
Consideration for bleeding and pulpotomies
Use cotton pellet to control bleeding
If bleeding doesnt stop in 3-5 min, proceed to pulpectomy
Does predental retrognathic mandible indicate future malocclusion?
Not necessarily - this is normal transient malocclusion
What is infantile swallowing and how is it different to mature swallowing
Self correcting anomaly
carried out by stomatognathic system
- Jaws apart, tongue placed btw upper and lower gum pads
- Nipple drawn into mouth
- Milk is directed into pharynx
- Swallow is guided and controlled as a sensory interchange between lips and tongue
How is infantile swallowing self corrected? (2)
- Gradually disappears with eruption of teeth and as infant starts to eat solid food (approx 1 year)
- When tongue is contained within dental arch
When does infantile swallowing correct itself (years)
around 1 year
- baby starts to eat solid food and have teeth erupt
Child has a deep over bite at 2 years old. Tx?
None - this is a self correcting anomaly
When is your primary dentition in place?
6 months to 3 years
Early vs late mesial shift
Early - using primate spaces
Late - using leeway spaces
What causes mandibular anterior crowding?
SCA
Larger permanent md anteriors erupting in a still narrow arch
How is mandibular anterior crowding self corrected?
Jaw expansion/growth → increased inter-canine width
Tongue pressure → forward migration of md ants
How does minor crowding differ from moderate crowding resolvement in the md anterior region?
SCA
Minor → resolves spontaneously by development
Moderate → Use of leeway space
May consider lingual arch to prevent mesial movement of permanent molar
what is “End on” relationship?
Buccal cusp tip of perm mx 6 coincides with buccal cusp tip of perm md 6
What is this and how does it self correct? (2)
“End on relationship”
Corrected by:
- Eruptive force in mesial direction of perm mandibular molars
- Late shift in non-spaced dentition
75% will shift into class 1 without treatment
25% will shift into class 2
How is minor overbite and overjet self corrected in the permanent dentition
By eruption of all permanent molars
Differential growth of mandible
Overbite will be decreased up to 0.5 mm by 18
Overjet will be decreased up to 0.7 mm by 20
