Effectiveness of an Oral Health Literacy Intervention on Oral Health Behaviors and Plaque Index in Orthodontic Patients

The outcomes were oral health behavior (OHB) and plaque index (PI), compared at three time points: baseline (initial), post-intervention (final), and at a 3-week follow-up. Additionally, as a manipulation check, oral health literacy (OHL) levels were assessed at all three intervals.

Demographic information, OHL, and OHB were measured using standardized questionnaires from previous research. The 31-item OHL scale assessed five elements: 1) access, 2) understanding, 3) evaluation, 4) application, and 5) communication of oral health information and services. A 14-item scale evaluated OHB across three domains: 1) oral hygiene practices, 2) dietary choices, and 3) utilization of dental services.

In addition, clinical assessments of plaque were conducted using the Silness and Löe plaque index (PI, 1964). Plaque was evaluated on four surfaces of each tooth (mesial, distal, buccal, and lingual) using a WHO probe. Scores ranged from 0 to 3, reflecting the absence to a large amount of plaque accumulation, based on their established criteria. A single oral examiner recorded the plaque scores for each surface, and the average score for each tooth was calculated. The total score was then summed and divided by the total number of teeth examined, providing an overall plaque index for each individual. There were no outcome changes after trial commencement.

Inclusion criteria

• participants undergoing fixed orthodontic treatment, free from non-communicable chronic diseases (such as diabetes mellitus, hypertension, and heart disease), capable of reading, writing, and providing informed consent, and willing to participate in the oral health program.

Exclusion criteria

• reluctance to provide health information, inability to complete assessments, or withdrawal from the program at any stage.