[Scientific rationale for Clinical Practice Guidelines (part 1): what are the factors that determine the choice of retention?].

Introduction: Retention is the set of means, processes or devices that contribute to maintaining the teeth in the position and the arches in the shape given by the orthodontic treatment. The main objective is to propose Clinical Practice Guidelines (CPG) on orthodontic retention by answering 4 main questions. This article provides the answer to the first question: What are the factors that determine whether or not to use a retainer?

Material And Methods: A literature review was carried out after a bibliographic search using keywords in bibliographic databases and in international organizations websites.

Results: 652 articles were selected after the bibliographic search, and only 53 met the inclusion criteria. These were used to develop the CPG full-text and guidelines.

Discussion: 12 CPGs were issued from this review, divided into 15 items, 8 of which were grade C and 7 were expert agreements.

Conclusion: 40 CPGs about orthodontic retention were proposed from this literature review, 12 of which are presented in this first part. The stability of orthodontic treatment depends on the initial orthodontic anomalies, residual growth, orthodontic treatment modalities, and the final occlusion. Orthodontists must consider the effectiveness of the appliances, the patients' compliance and oral hygiene. The amount of alveolar bone, the neuromuscular and functional balance are relapse factors.