Motivational Interview and Orthodontic Patients
Condition: Motivational Interviewing; Oral Hygiene; Orthodontic Appliance Complication
Study type: Interventional

Summary: 
      A parallel-group randomized clinical trial was conducted with 45 patients of the Orthodontic
      Clinic of Universidad Iberoamericana's (UNIBE) Postgraduate Unit. The study hypothesis was
      that motivational interview plus oral hygiene instructions would be more effective in
      maintaining long-term oral hygiene in comparison with conventional oral hygiene instructions
      alone.

      A computer-generated list of numbers created with Statistical Package for the Social Sciences
      (SPSS) V21.0 was used to random allocate participants into the experimental or the control
      group. Monthly oral hygiene instructions and a G.U.M. kit were given to the sample.
      Additionally, the experimental group received motivational interviewing sessions by a trained
      periodontist. Simplified Oral Hygiene Index, Gingival Index, Periodontal Probing Depth and
      Bleeding on Probing were recorded at baseline, three and six months after the beginning of
      the study. Repeated-measures analysis of variance and chi-squared test were conducted.
    

Detailed description: 
      Sample calculation A power analysis was carried out to determine the number of subjects
      needed to achieve a Simplified Oral Hygiene Index (SOHI) significant interaction with the
      study groups when applying repeated measures ANOVA. The total number of completed subjects
      needed to achieve power of 0.90 with an alpha (α) of 0.05, an effect size (f) of at least .25
      was determined to be 36; taking into consideration a possible 10% attrition rate, 45 subjects
      were recruited, consented and randomized to either the experimental or control group.

      Due to the matter that repeated measures ANOVA treats each measurement as a separate
      variable, and it's preferable to use listwise deletion, if one measurement is missing, the
      whole case gets dropped. For this reason and therefore the incontrovertible fact that the
      trial suffers attrition, the sample for the three measurements was reduced to 32 subjects.

      Randomization A simple randomization procedure was executed by the principal investigator to
      allocate the participants into one of the study groups. A computer-generated list of numbers
      was created using the software SPSS V21.0, with a 1:1.25 allocation ratio.

      Two dentists enrolled and allocated the participants according to the order of arrival and
      following the list of random numbers. A coding system was used as a concealment mechanism,
      which consisted of colored labels attached to the participants' file. Thus, the participant
      and the evaluator (the periodontist who recorded the data) were masked.

      Study intervention An interviewer was in charge of providing oral hygiene instructions for
      both groups. All the participants received a G.U.M. kit with special orthodontic hygiene
      tools. Then, the patients of the experimental group received a motivational interviewing
      session.

      Afterward, the clinical parameters were measured by another periodontist. Monthly follow-up
      appointments were scheduled for the orthodontic check-ups to deliver a new G.U.M. kit, to
      reinforce the OHI and MI, and to register the periodontal parameters. The important data for
      this research was the one recorded at baseline, three and six months after the intervention.

      Statistical analysis Mean Simplify oral hygiene index (SOHI), gingival index (GI),
      periodontal probing depth (PPD), and bleeding on probing (BoP) scores were compared between
      groups across three-time points using repeated-measures mixed-model analysis of variance.
      Tests for equality of variances and sphericity to check for homoscedasticity were performed
      due to the problem of sample attrition. Nevertheless, it was not found any violation to these
      assumptions in any of the variables included in the analysis. SPSS software was used for all
      calculations (IBM SPSS 25th version). Due to the nominal level of measurement of the variable
      BoP, it was performed a chi-squared test for each three time points to check if there were
      any differences between the two experimental conditions.
    

Intervention name(s): Motivational interviewing; Oral Hygiene Instructions
Intervention type(s): Behavioral; Behavioral
Intervention description(s): A periodontist was trained and evaluated by two expert psychologists in MI, who also supervised the interviewer to ensure that the intervention was properly applied. The periodontist conducted sessions of motivational interviewing monthly to the participants of the experimental group.; A periodontist delivered OHI to all the participants of both studied groups. Also, every single patient received a G.U.M. kit with special orthodontic hygiene tools.
Other intervention name(s): Motivational interview; OHI
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: Orthodontic patients were recruited to be divided into a control group (that received oral hygiene instructions) and an experimental group (that received oral hygiene instructions and motivational interviewing sessions).
Masking: Double (Participant, Outcomes Assessor)
Primary purpose: Prevention
Keywords: Motivational interviewing; Oral hygiene; Fixed orthodontic appliances; Treatment adherence