Orthopedic_Appliance_Chin_Cup_Seminar (2).pptx

Chin up appliance in orthodontics orthopedic treatment which help to treat class iii malocclusion

1. Orthopedic Appliance: Chin Cup Prepared by: Ali Dhiaa Department of Orthodontics

2. Introduction to Orthopedic Appliances Orthopedic appliances are used to modify or redirect skeletal growth. Chin cup is specifically designed to control mandibular growth in Class III malocclusion.

3. Definition The chin cup is an extraoral orthopedic appliance used to restrain or redirect excessive mandibular growth. It applies an upward and backward force to the mandible via the chin.

4. Aims and Objectives - Restrain mandibular growth - Correct skeletal Class III malocclusion - Improve facial esthetics - Establish stable occlusal relationship

5. Types of Chin Cup 1. Occipital Chin Cup: Force directed upward and backward → backward mandibular rotation. 2. Vertical Chin Cup: Force directed vertically upward → control vertical mandibular growth.

6. Force Direction vs Growth Direction Normal mandibular growth occurs forward and downward at the condyle. Chin cup applies an opposing upward and backward force. This redirects growth, causing posterior rotation and inhibition of condylar growth.

7. Indications - Skeletal Class III malocclusion due to mandibular prognathism - Growing patients with active mandibular growth - Mild to moderate skeletal discrepancies - Forward positioning of mandible with normal maxilla

8. Age and Stage of Growth • Ideal age: 6–10 years (early mixed dentition) • Effective before or during pubertal growth spurt • Ineffective after growth completion

9. Parts of Chin Cup 1. Chin Cap/Cup – Acrylic or padded area that fits the chin 2. Head Cap/Occipital Strap – Provides anchorage 3. Elastic Bands – Apply orthopedic force (350–500g per side) 4. Hooks/Connectors – Adjust direction and force magnitude

10. Clinical Use • Worn 12–14 hours/day, mainly at night • Adjust every 4–6 weeks • Continue until desired skeletal correction achieved

11. Mechanism of Action • Backward mandibular rotation • Inhibition of condylar growth • Remodeling at TMJ area • Stretching of soft tissues • Changes in SNB and ANB angles

12. Growth Direction Comparison Without appliance: Mandible grows forward and downward. With chin cup: Force redirects growth backward and downward, reducing prognathism.

13. Clinical Results ✓ Reduced chin prominence ✓ Improved overjet/overbite ✓ Balanced facial harmony ✓ Stable correction when applied early

14. Limitations and Precautions - Limited effect after growth spurt - Requires patient compliance - Possible skin irritation - Risk of relapse without retention

15. References 1. Proffit WR et al. Contemporary Orthodontics, 6th ed, 2018. 2. Graber LW et al. Orthodontics: Current Principles and Techniques, 6th ed, 2017. 3. Mitani H, Fukazawa H. Am J Orthod, 1986. 4. Sugawara J, Mitani H. Angle Orthodontist, 1993. 5. Proffit WR, Ackerman JL. Seminars in Orthodontics, 2000.