Serial Extractions

Question 1

Early orthodontic intervention
Indications:
(8)

Answer 1

1. Posterior & anterior crossbites.
2. Ankylosed teeth.
3. Excessive protrusions and diastemas.
4. Severe anterior and lateral open bites.
5. Ectopic molars.
6. Pseudo Class III patients.
7. Cleft palate patients.
8. Severe arch length discrepancies.

Question 2

Evaluated the available space by changes in
(2)

Serial dental casts of 182 North American white
individuals between 3 and 16-18 years of age

Answer 2

intercanine width and arch length

Question 3

Changes in Arch Dimension
Maxilla AL
Primary
Mixed
Permanent

Answer 3

28.5
29.9
28.8

Question 4

Changes in Arch Dimension
Maxilla IC
Primary
Mixed
Permanent

Answer 4

28.8
32.0
33.6

Question 5

Maxillary arch …
Maxillary intercanine distance …

Answer 5

length remains the same
increases 4.8mm

Question 6

Changes in Arch Dimension
Mandible AL
Primary
Mixed
Permanent

Answer 6

25.5
25.3
23.5

Question 7

Changes in Arch Dimension
Mandible IC
Primary
Mixed
Permanent

Answer 7

22.3
25.5
25.5

Question 8

Mandibular arch length …
Mandibular intercanine distance …

Answer 8

decreases 1.7mm.
increases 3.2mm

Question 9

Leveling the curve of Spee: its effects on
mandibular arch length
To estimate the needed arch length to level the
curve of Spee, measure the

Answer 9

maximum depth of
the curve on both sides, get the average
measurement and add 0.5mm

Question 10

Interpretation of the Mixed Dentition Analysis.
If the mixed dentition analysis predicts that
there is not a crowding problem,

Answer 10

continue with
periodic patient observation.

Question 11

If the mixed dentition analysis predicts light
crowding (1 - 4 mm.),

Answer 11

maintain the arch length
with any appliance and examine the patient
periodically, probably there will be a need for
future orthodontic treatment

Question 12

If the mixed dentition analysis predicts crowding
of more than 4mm.,

Answer 12

most probably the patient
will develop crowding in the permanent dentition
which will require orthodontic treatment after a
thorough evaluation

Question 13

If the mixed dentition analysis predicts crowding
in excess of 6mm. In the mandibular arch, the
patient will benefit form

Answer 13

serial extraction therapy

Question 14

Serial extraction is the orderly removal of
deciduous and permanent teeth in a determined
sequence.
(6)

Answer 14

1. Skeletal class I.
2. Dental class I.
3. Bimax dental protrusion.
4. Dental crowding in excess of 6mm.
5. Light or anterior open bite tendency.
6. No congenitally missing second bicuspids

Question 15

Main benefits of serial extraction.
(5)

Answer 15

1. Naturally induced movement and
   alignment of severely crowded anterior
   teeth.
2. Health improvement of the adjacent
   tissues.
3. Psychological and cooperation
   improvement, due to the incisor
   alignment.
4. Decrease on the orthodontist work load
   and stress.
5. Less iatrogenic damage.

Question 16

Main disadvantages of serial extraction.
(4)

Answer 16

1. Increase of the overbite.
2. Lingual inclination of incisors.
3. Scaring tissue on the extraction spaces.
4. Diastemas.

Question 17

Prerequisites in serial extraction
Conventional serial extraction:
(3)

Answer 17

1. Premature extraction of deciduous canines
   provides the space for the incisors to assume
   normal position over supporting bone.
2. Extraction of the first deciduous molars permits
   the desirable early eruption of the first premolars.
3. Final extraction of first premolars makes it
   possible for the canines to erupt in a favorable
   direction

Question 18

Alternative serial extraction:
(6)

Answer 18

1. Borderline malocclusion (extraction?).
2. Deciduous cuspids present.
3. Moderate loss of arch length.
4. No irregularity on lower incisors.
5. No gingival recession.
6. Second deciduous molars in place for a long
   time.