Stability, retention and relapse in orthodontics

Abstract

This remarkable and beautifully illustrated book is essential reading for any clinician interested in the long-term survival of orthodontic treatment outcomes. The premise is a thorough understanding of stability, retention, and relapse should enable the clinician to plan individualized treatments that have a greater chance of favourable long-term results. There is a discussion of the tooth and jaw movements that consistently have been associated with an increased risk of relapse. In addition, retention protocols, materials, and techniques are reviewed and analyzed in order to give expert guidance for the prescription of individualized retention. The 13 chapters cover three main subject areas; the history and biology of retention, a detailed review of the current understanding of stability for various treatment methodologies, and a detailed discussion of contemporary retention strategies. Each chapter has been compiled by acknowledged experts in the field and information is presented as a series of reviews, systematic reviews, evidence based protocols, and advice on best clinical practice. Stability of treatment is explored in the following subject areas; arch dimension (mostly lower incisor integrity), transverse arch expansion, Class II correction , Class III correction, anterior open bite, and orthognathic surgery. It will be of interest to older members of the profession that the Index does not contain an entry relating to extraction although the subject is discussed briefly in relation to Class II correction. How times have changed! The final chapters cover fixed retention and give a detailed review of in vitro properties of various wires and adhesives, together with available evidence for 'long-term' survival in the clinical situation. Unfortunately, the current evidence base is not able to make recommendations about the wire type. One humbling observation is that fixed retention is a technique sensitive procedure requiring careful enamel preparation, effective moisture control, and adequate adhesive distribution. Research suggests there are few long-term complications arising from the use of fixed retainers but recently there have been reports of bizarre changes in tooth torque and adverse root movement. Although this is an unusual complication, this raises the question about who should be responsible for the long-term supervision of fixed retainers; either the orthodontist, who may recognize adverse changes, or the general dental practitioner, who may not. This publication is to be highly recommended reading for any member of the profession who is interested in best clinical practice.