Chin-cup

Question 1

What is the rationale of Chin-cup therapy?

Answer 1

Restrain Mn growth by directing compressive forces in a straight line of action towards the mandibular condyles

• alter Mn form and condylar growth

Question 1

Evidence for effect of Chin-cup therapy

Answer 1

Sugawara et al. 1990
Deguchi et al. 2002
Mitani et al. 2002

Question 2

What does the evidence say?

Answer 2

Sugawara and Mitani:
AP changes in the 1st 2-3 years of wear not always maintained if discontinued before growth completion.
- advice to continue till growth complete

Question 3

What are the dental and skeletal changes?

Answer 3

Skeletal:

• reduced ramus/ gonial angle
• ANB
• Wits

Dental:

• Mesialisation of U6s
• Labial mvm of Ui
• Retro Li from pressure of appliance on L lip and dentition

Question 4

Would you recommend? Cochrane review

Answer 4

Watkinson et al. 2013

NO evidence to support anything apart from FM (short term)

Question 5

Is it still indicated? (7points)

Answer 5

Ngan and Moon, 2015:
NO
- true Sk. III 
- prog Mn
- req sx
- normal cranial base angle
- no TMD
- normal LAFH
- mild AP