Gingival Crevicular Fluid Cytokine Levels in Response to Orthodontic Forces
Condition: Orthodontic Tooth Movement
Study type: Interventional

Summary: 
      The aim of this randomized split-mouth study was to quantify simultaneously 30 analytes
      including cytokines, chemokines and growth factors in gingival crevicular fluid (GCF) in
      response to different magnitudes of forces during maxillary canine distalization. The upper
      right and left canines were distalized using a continuous force of 75 g or 150 g in 15
      individuals who had Class II division I malocclusion requiring bilateral extraction of
      maxillary first premolars. GCF samples were obtained from the tension and the pressure side
      of each canine at appliance placement and after force application at 24 hours and 28 days. A
      multiplexed bead immunoassay was used to quantify 30 analytes simultaneously. The effect of
      force, side and time on the analyte levels were analyzed with Brunner-Langer method.
    

Detailed description: 
      Patient selection:

      Fifteen orthodontic patients with class II division I malocclusion, who required the
      extractions of maxillary first premolars bilaterally, distal canine movement, and maximum
      anchorage control as a part of fixed orthodontic treatment plan were invited to participate
      in the study. All subjects were in good general health with clinically and radiological
      healthy periodontal tissues (the probing depths ≤3 mm, full-mouth plaque and bleeding score
      ≤15%, and no bone loss radiographically). Patients were excluded if they were smokers, had
      had previous orthodontic treatment, had taken a course of anti-inflammatory drugs within 1
      month and antimicrobial agents in the previous 3 months prior to the start of the study.

      Experimental Design:

      The first premolars were extracted at least 20 days prior to the distalization of the
      canines. Ten days prior to the application of orthodontic force all subjects underwent
      full-mouth scaling and oral hygiene instructions to ensure optimal plaque control and oral
      hygiene instruction was reinforced throughout the whole study period. In each patient, two
      mini-screw implants (1.5 mm in diameter and 8.0 mm in length) were placed bilaterally into
      the inter-radicular bone between the maxillary second premolar and first molar in the
      attached gingiva.The upper right and left canines of the same patient were randomly
      distalized using a continuous force of 75 or 150 g with nickel-titanium closed coil springs.
      Simple randomization by flipping a coin was used to determine the assignment of each site for
      two different forces.

      GCF sampling:

      GCF was sampled from the mesial (tension) and distal (pressure) sides of maxillary right and
      left canines immediately before appliance placement (baseline) and after force application at
      24 hours and 28 days without any reactivation of the coil spring. Baseline measurements of
      maxillary canines served as a control.

      Clinical Periodontal Measurements:

      Periodontal clinical parameters including probing depth, clinical attachment loss, gingival
      index and plaque index were recorded at mesial and distal sites of distally moved canines at
      baseline and 24 hours and 28 days after force application. All clinical periodontal
      examinations were performed by a single calibrated periodontist who blinded to the groups
      using a manual periodontal probe.

      Multiplex assay& Quantification of inflammatory mediators:

      A commercially available multiplex panel including thirty proteins was used to evaluate GCF
      content on the Luminex®200 platform.

      Determination of the amount of tooth movement:

      The distance of maxillary canine movement was measured from the cusp tip of a distally moved
      canine to the buccal groove of the first permanent molar by using a digital caliper with a
      sensitivity of ±0.01 mm.

      Statistical Analysis:

      The data was analysed using a statistical software package. The effect of force, side and
      time on the analyte levels were analyzed with Brunner-Langer method.
    

Intervention name(s): Canine distalization
Intervention type(s): Other
Intervention description(s): GCF was sampled from the mesial (tension) and distal (pressure) sides of maxillary right and left canines immediately before appliance placement (baseline) and after force application (24 hours and 28 days)
Other intervention name(s): Gingival crevicular fluid collection
Allocation: Randomized
Intervention model: Sequential Assignment
Masking: Single (Investigator)
Primary purpose: Treatment
Keywords: Canine distalization; Gingival crevicular fluid; Cytokines; Orthodontic force; Periodontium; Gingivitis