Indication and timing of soft tissue augmentation at maxillary and mandibular incisors in orthodontic patients.  A systematic review. 
To assess the indication and timing of soft tissue augmentation for prevention or treatment of gingival recession when a change in the inclination of the incisors is planned during orthodontic treatment.  Electronic database searches of literature were performed.  The following electronic databases with no restrictions were searched: MEDLINE, EMBASE, Cochrane, and CENTRAL.  Two authors performed data extraction independently using data collection forms.  No randomized controlled trial was identified.  Two studies of low-to-moderate level of evidence were included: one of prospective and retrospective data collection and one retrospective study.  Both implemented a periodontal intervention before orthodontics.  Thus, best timing of soft tissue augmentation could not be assessed.  The limited available data from these studies appear to suggest that soft tissue augmentation of bucco-lingual gingival dimensions before orthodontics may yield satisfactory results with respect to the development or progression of gingival recessions.  However, the strength of the available evidence is not adequate in order to change or suggest a possible treatment approach in the daily practice based on solid scientific evidence.  Despite the clinical experience that soft tissue augmentation of bucco-lingual gingival dimensions before orthodontic treatment may be a clinically viable treatment option in patients considered at risk, this treatment approach is not based on solid scientific evidence.  Moreover, the present data do not allow to draw conclusions on the best timing of soft tissue augmentation when a change in the inclination of the incisors is planned during orthodontic treatment and thus, there is a stringent need for randomized controlled trials to clarify these open issues.