Orthodontic treatment and root resorption of teeth: Critical analysis of mechanical factors.

AIM: The aim of this review is the presentation and critical analysis of the mechanical factors associated with orthodontic treatment and implicated in the formation of root resorption.METHOD: Original articles and reviews pertaining to this topic were searched at the data base PubMed until May 2009.FINDINGS: Root resorption shows considerable variations. Individuals may present minimal or significant resorption, more than 3 mm while a percentage of 5% may present more than 5 mm. The magnitude of forces applied by the orthodontist seems to be among the mechanical factors that may affect the formation of resorptions, while intrusion and jiggling seem to be the most harmful among the teeth movement types. Teeth resorptions also seem to be associated with the type and duration of the applied forces, the range of tooth movement, as well as with genetic and biological factors, rendering this way the dissociation and the degree of participation of these factors in the appearance of resorptions particularly difficult.CONCLUSIONS: Root resorptions of teeth are an unanticipated phenomenon of multifactorial etiology. Up until now, it seems that there is not enough evidence that could lead to specific strategies efficient to minimize or prevent the phenomenon of root resorption.