EXTRACTION Vs NON EXTRACTION

Question 1

What was Angles philosophy re to XTN ?

Answer 1

Everyone had the capacity for all 32 teeth.

Best aesthetics with all 32 teeth

Therefore believed in expansion phiosophy which related to Wolffs Law= Bone would form in response to stress.

Question 2

WHY EXTRACT TEETH ?

Answer 2

• Releif of cx with XSV expansion.
• OJ and OB reduction
• Anchorage consideration
• Buccal segement relationship correction.
• Incisor relaitonship EG: in CLIII cases lower inc xtn to allow for retroclinatio of LLS to correct incisor relationship.

Question 3

DISADVANTAGES OF XTN’s?

Answer 3

• Longer RX
• More difficult RX.
• Pain anxiety
• Other risk factors associated with extractions

Question 4

Classification of severity of crowding according to Proffit et al 2012

Answer 4

• 0-4mm= MILD
• 4-8= MODERATE
• >/= 9mm= SEVERE

Question 5

• What are the main saliant points relating to xtn/non xtn and facial profile ?

Answer 5

• PM xtns seem to have small effect on profile but not necessarily detrimental.
• Growth is the overriding factor
• Evaluation of profile is highly subjective
• XTN did NOT result in narrower MX dental arches
• Lip percumbency improves following xtn of 4 pm’s. This improvement is predictable. The changes are small and do not dramatically modify the portfolio.
• Individual variation in response is large.
• Inappropriate xtns will reduce lip support.