Does orthodontic treatment lead to gingival recession?

DATA SOURCES: Medline, Embase, The Cochrane Central Register of Controlled Trials (CENTRAL) and the reference lists of identified studies.

STUDY SELECTION: Human controlled or randomised clinical trials and animal studies reporting occurrence of gingival recession and crown length changes were included. Case reports, descriptive studies, review articles, opinion articles and studies concerning impacted teeth or injured anterior teeth, pre-orthodontic treatment for dental restoration and those limited to severe periodontal diseases or craniofacial anomalies were excluded. Articles in any language were considered.

DATA EXTRACTION AND SYNTHESIS: Data were recorded on specially designed data extraction forms and the studies were graded with a score of A-C (Grade A: high value of evidence, Grade C: low value of evidence) according to predetermined criteria, and a narrative synthesis presented.

RESULTS: 17 articles were included: six experimental animal studies and 11 retrospective clinical studies in humans. More proclined teeth compared with less proclined teeth or untreated teeth had in most studies a higher occurrence or severity of gingival recession. Contradictory results were found regarding a possible statistically significant correlation between the extent of gingival recession and the amount of incisor proclination during treatment, width of attached gingiva, hygiene, periodontal condition or thickness of the symphysis.

CONCLUSIONS: There are no high quality animal or clinical studies on this topic. Movement of the incisors out of the osseous envelope of the alveolar process may be associated with a higher tendency for developing gingival recession. The amount of recession found in studies with statistically significant differences between proclined and non-proclined incisors is small and the clinical consequence questionable. Because of the low level of evidence of the included studies, the results should be considered with caution.