Bearing Pendulum Extraction Case

Introduction

The “swinging pendulum” of extraction versus non-extraction treatment began with the Dewey – Case Debates of 19111, and remains unresolved to this day. E. H. Angle (1905), initially provided extraction treatment for his patients, but modified his approach to non-extraction therapy based upon the philosophy that ‘a full complement of teeth’ can be maintained by modifying the environment surrounding the dentition.2 Opposed to this non-extraction mode of therapy were Tweed and Begg (1963), who have reported patients demonstrating relapse during the retention period. They have advocated that more stable results could be achieved through treatment with extraction.3

In order to reach a decision on the preferred

But the question that arises is, why has the pendulum swung towards the non-extraction mode of treatment over the past decennia? (26.8% of cases treated with extraction in the last decade compared to 50% in 1980s)11

Arch Changes in Non-Extraction

Space is required in dental arches in cases of arch length-tooth size discrepancies; to relieve crowding, leveling of curve of spee, correct transverse and antero-posterior deficiencies. Various methods of gaining space are employed in Orthodontics, besides extraction; Proximal reduction, distalization of molars and expansion. Arch expansion is one of the conservative methods of gaining space.

Types of Expansion
• Orthodontic Expansion:
Predominantly dentoalveolar changes produced by lateral movement of the buccal segments- Conventional fixed appliance, Self-ligating appliance, Wilson arch, Expansion screws, Coffin spring.
• Orthopaedic Expansion:
Predominantly skeletal changes produced by the separation of mid-palatal suture-Rapid maxillary expansion appliance; Hyrax, Haas, Isaacson, Derichsweiller.

Techniques for Expansion
• Removable appliances
• Rapid maxillary expansion
• Fixed

The proposed core advantages of self-ligating system19
● More certain full archwire engagement
● Low friction between the bracket and the archwire
● Greater arch expansion with less incisor proclination
● Faster archwire ligation and removal

Particularly, claims that more stable transverse arch expansion with minimal incisor proclination can be achieved with self-ligating systems, offer a paradigm shift in treatment that entails fewer extractions and more arch expansion.17 However, it subsequently raised questions about the stability of results and the feasibility of long-term retention provided by this technique.16

Dwight Damon (1998)17 clarified the dubiety with his philosophy of ‘Bioadaptive response’ and ‘Biozone’.

Bioadaptive