The monitoring of orthodontic tooth movement over a 2-year period by analysis of gingival crevicular fluid.

Gingival crevicular fluid (GCF) was collected from around canine teeth before orthodontic treatment, during retraction, and in retention. The aim was to investigate the changes in the flow of GCF and its glycosaminoglycan (GAG) components at these three stages of orthodontic treatment, and relate them to tooth movement, gingival inflammation, and other clinical parameters recorded at the time of GCF sampling. GAG in GCF samples, collected for a 15-minute period into microcapillary tubes, were separated and identified electrophoretically, stained with Alcian blue and quantitated using a laser densitometer. The increase in GCF volume during orthodontic tooth movement and the decrease during retention are only partly due to changes in the severity of gingival inflammation. Levels of the GAG component chondroitin sulphate found in GCF samples taken during retention appear to be related to the duration of retention, particularly the length of time that the fixed appliance is passive before debonding. GCF analysis may assist the clinician to conduct this phase of orthodontic retention more reliably.