Serial Extractions

Question 1

What are the indications for early orthodontic intervention?

Answer 1

• posterior & anterior crossbites
• ankylosed teeth
• excessive protrusions and diastemas
• severe anterior and lateral open bites
• ectopic molars
• pseudo class III patients
• cleft palate patients
• severe arch length discrepencies

Question 2

When a growth study was performed on North American white individuals (ages 3- 18 years old) to evaluate the available space by changes in intercanine width and arch length, what did they find?

Changes in maxillary arch length…

Answer 2

remains the same

Question 3

When a growth study was performed on North American white individuals (ages 3- 18 years old) to evaluate the available space by changes in intercanine width and arch length, what did they find?

Changes in mandibular arch length…

Answer 3

decreases 1.7mm

Question 4

When a growth study was performed on North American white individuals (ages 3- 18 years old) to evaluate the available space by changes in intercanine width and arch length, what did they find?

Changes in the maxillary intercanine distance…

Answer 4

increases 4.8mm

Question 5

When a growth study was performed on North American white individuals (ages 3- 18 years old) to evaluate the available space by changes in intercanine width and arch length, what did they find?

Changes in the mandibular intercanine distance are…

Answer 5

increases 3.2mm

Question 6

To estimate the needed arch length to level the curve of Spee, measure the…

Answer 6

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

Question 7

If the mixed dentition analysis predicts that there is not a crowding problem what should you do?

Answer 7

continue with periodic patient observation

Question 8

If the mixed dentition analysis predicts light crowding (1 - 4 mm.) what should you do?

Answer 8

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

Question 9

If the mixed dentition analysis predicts crowding of more than 4mm. what should you do?

Answer 9

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

Question 10

If the mixed dentition analysis predicts crowding in excess of 6mm. in the mandibular what should you do?

Answer 10

the patient will benefit form serial extraction therapy

Question 11

What is serial extraction?

Answer 11

orderly removal of deciduous and permanent teeth in a determined sequence

Question 12

What are the prerequisites in serial extraction?

Answer 12

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 13

What are the main benefits of serial extraction?

Answer 13

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 14

What are the main disadvantages of serial extractions?

Answer 14

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

Question 15

What are the two types of serial extractions?

Answer 15

• Conventional serial extraction
• Alternative serial extraction

Question 16

What are the characteristics of conventional serial extraction?

Answer 16

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 17

What is the order for conventional serial extractions?

Answer 17

• deciduous canines
• first deciduous molars
• permanent first premolars

Question 18

What are the characteristics of alternative serial extractions?

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