Fixed Appliances Consistently Raised Gingival Inflammation, Systematic Review Finds

Edited by Orthotown staff

Fixed orthodontic appliances consistently increase gingival inflammation through plaque retention, and that effect is generally reversible once the appliances come off, according to a systematic review of risk factors for dental biofilm-induced gingivitis published Sept. 17 in the Journal of Clinical Periodontology.

Appliances were the most studied of the local factors the review examined. Removal produced a significant reduction in inflammation across the studies consistently enough for the authors to state the finding without qualification.

Evidence on a related question was weaker. Whether orthodontic correction of malalignment or severe crowding changes gingival inflammation was addressed by only a few studies, and the review described that evidence as limited.

Investigators screened 11,529 records and included 71 papers, restricting eligibility to longitudinal studies of at least three months or studies using the experimental gingivitis protocol. Fifty-five papers addressed risk factors and indicators, and 16 addressed interventions.

Other local factors drew less attention. Some studies found higher gingival index scores at sites with defective, overhanging, or subgingival restorative margins.

Among systemic factors, a pro-inflammatory or high-sugar diet increased risk, while an anti-inflammatory or low-sugar diet and dietary counseling could reduce it. In patients with pre-existing gingivitis, menstrual cycle hormone fluctuations and gonadotropin-induced ovarian stimulation were associated with increased inflammation independent of plaque levels. The review found no convincing evidence that overweight or obesity increases risk, attributing that to a lack of studies rather than to negative findings.

Researchers at Université Paris Cité and Sorbonne Paris Nord led the review, with colleagues at the University of Bonn, the University of Marburg, and the University of Medicine and Pharmacy Iuliu Ha?ieganu in Cluj-Napoca. The protocol was registered with PROSPERO and the review followed PRISMA guidelines.

The authors concluded that certainty of evidence varies across the factors examined, and that oral hygiene instruction and professional mechanical plaque removal should be intensified in affected patients, with dietary advice considered as an adjunct.

Sources:
Journal of Clinical Periodontology, “Local and Systemic Risk Factors of Dental Biofilm-Induced Gingivitis and Their Control: A Systematic Review,” published online Sept. 17, 2026: doi.org/10.1111/jcpe.70189
PubMed record, PMID 42751832: pubmed.ncbi.nlm.nih.gov/42751832