Related Experiment Video
Updated: May 11, 2026

Oral Biofilm Sampling for Microbiome Analysis in Healthy Children
Published on: December 31, 2017
Differences in the gingival crevicular fluid composition between adults and adolescents undergoing orthodontic
Wellington J Rody1, Manjula Wijegunasinghe, William A Wiltshire
1a Assistant Professor, Department of Orthodontics, College of Dentistry, University of Florida, Gainesville.
Objectives:
To investigate differences in the gingival crevicular fluid (GCF) composition between adolescent and adult patients undergoing orthodontic treatment with fixed appliances.
Materials And Methods:
Ten adolescents (14.4 ± 1.43) and 10 adults (28.5 ± 7.83) with Class I malocclusions and minor upper incisor crowding were allocated to two different age groups. Brackets were bonded only in the upper arch over the 20-week period of the experiment. Samples of GCF were collected from the labial sides of the upper incisors (experimental sites) and lower incisors (control sites) of each subject at five time points. Aliquots from diluted GCF were screened for the presence of receptor activator of nuclear factor kappa B ligand (RANKL), osteoprotegerin (OPG), interleukin-1 (IL-1), interleukin-1 receptor antagonist (IL-1RA), and metalloproteinase-9 (MMP-9) using a microarray technique. The values were statistically analyzed.
Results:
In adults, the ratio of IL-1 to IL-1RA decreased significantly (P = .033) in experimental sites 3 weeks after appliance placement and first archwire activation. In adolescents, the ratio of RANKL to OPG peaked 6 weeks after the insertion of the first rectangular archwire. This ratio peak found in adolescents was a consequence of a decrease in the mean concentration of OPG. No significant changes over time were observed in the concentration of MMP-9.
Conclusion:
This study demonstrates age trends in the GCF levels of IL-1, IL-1RA, RANKL, and OPG that may be used to track differences in tissue response between adults and adolescents undergoing orthodontic treatment.
Related Concept Videos
Development of the Oral Microbiota
Teeth
In the bud stage, the tooth germ (an aggregation of cells) starts to form in the developing jawbone. During the cap stage, the tooth germ differentiates into enamel organ, dental papilla, and dental sac, which will later develop into the tooth's enamel, dentin and...
The Oral Microbiota
Assessment of the Mouth
Mouth Inspection
The inspection begins with visually examining the mouth for symmetry, color, and size.
