Crowding in mixed dentition
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Transcript Crowding in mixed dentition
By: Dr. Richa Khanna
Crowding in mixed dentition is a common finding
especially in mandibular anterior region
The most important reason for lower incisor
crowding in mixed dentition is
‘Incisal liability’
Factors that help to resolve this crowding:
1.
INTERDENTAL SPACING
Help in lateral shift of deciduous canines when
permanent incisors erupt
If spacing is absent this shift is not possible,
and cances of self-alignment decrease
2. INTERCANINE ARCH WIDTH
Increase
in intercanine width help yo resolve
this crowding
The increase is about 6mm in maxilla and
4mm in mandible.
3. INCLINATION OF PERMANENT INCISORS- also
help to relieve crowding
4. Ratio of size of permanent and primary
teeth.
1.
2.
OBSERVATION – for space requirement less
than 2 mm.
DISKING OF PRIMARY TEETH
– for space requirement between 3-4 mm
- Can be done by strips or fine burs
- Teeth may correct spontaneously or may
need lingual arch with auxillary springs
3. EXTRACTION OF PRIMARY TEETH
-
Extractions are needed when space
requirements are ecxessive.
The most common procedure in this context
is SERIAL EXTRACTIONS
- coined by Kjellgren
- Popularised by Nance: known as ‘Father of
serial extraction’
- Also known as ‘GUIDANCE OF ERUPTION’
DEFINED AS:
Correctly timed, planned removal of
certain deciduous and permanent teeth in
mixed dentition stages with dentoalveolar
disproportion.
Class
I with anterior crowding(space disc. >
10mm)
Lingual eruption of lateral incisors
Midline shift potential due to unilateral
canine loss
Crowded arches with extreme proclination
Abnormal primary canine root resorption
Lack of developmental spacing
Anamolies such as ankylosis, ectopic eruption
Mid
to moderate crowding
Congenital absence of teeth
When removal of first permanent molars due
to caries is needed
Accompanying deep or open bites without
correction
Severe class II/III of dental or skeletal origin
Cleft lip/palate cases
Clinical
examination
Study models
X rays
M-d analysis
Photographs- facial
I.
II.
III.
Dewel: CD4
Tweed : D4C
Nance: CD4
May
need follow up fixed appliance therapy
Patient compliance is a factor
Not an option in case of impacted permanent
canines.
TSALD
MILD
expressed as mild
faciolingual displacement
or rotation
It is a transient
phase of
crowding
No treatment is usually needed except for slight disking
of primary molars or primary canines.
This slight crowding is solved by a slight increase in intercanine width,
labial positioning of the permanent incisors relative to the primary
incisors, and slight backward movement of the canines into the
primate space
TSALD
MODERATE
Always a challenge to the clinician.
Options: besides disking
Use leeway space
Regain space
Expand the arch
TSALD
SEVERE
Options:
Serial extraction
Expand the arch