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