In partial fulfilment of the requirements for the degree of Master in Medical Research.

Introduction: Malocclusion is treated with long-term use of fixed metallic orthodontic appliance. Orthodontic appliances possess a challenge to maintain oral hygiene resulting in plaque accumulation and progression to gingivitis. Oral health education and supervision help patients to adopt healthy behavior resulting in successful treatment outcome.

Objective: To evaluate the effectiveness of supervised tooth-brushing instructions on oral health status among orthodontic patients.

Materials and method: it is a prospective experimental study using simple random sampling technique; allocating 32 subjects as control and 30 as intervention group. Participants’ oral hygiene practice was recorded in a structured questionnaire. The intervention group was instructed and trained with supervised Charter’s brushing technique. The plaque accumulation and gingival conditions were recorded clinically through Orthodontic Plaque Index (OPI) and Gingival Index (GI) respectively at the baseline, after one month and after two months by a trained single examiner under plaque disclosing condition. The mean OPI and GI scored were compared at timelines using Repeated measures analysis and Friedman test respectively. The comparison between control and intervention groups for OPI and GI were done by independent t-test and Mann-Whitney U test respectively. Graded assessment of oral hygiene of oral hygiene and gingival status were depicted in proportions. The relationship between OPI and GI scores were checked using Spearman correlation analysis. Data were analyzed in SPSS V27.0 at the level of significance p<0.05.

Result: The recommended Charter’s tooth-brushing practice increased from 10% at baseline to 76.7% after two months of supervised training. There was a significant difference in mean OPI scores between control and intervention groups after two months (<0.001). The repeated measure analysis and pair-wise comparison further denoted significant differences among the mean OPI scores measured at all timelines in intervention group and significant difference in scores at baseline and after two months in control group. There was a reduction of 0.65 OPI score in the intervention group compared to control group.

There was a significant difference in mean rank GI scores between control group and intervention group after two months (P<0.001). Friedman test depicted significant difference in GI scores among time periods in control as well as intervention groups (P<0.001). Subsequently, Wilcoxon Sign Ranked test depicted significant difference in GI scores in control as well as intervention group at all time periods (P<0.001, 0.003). Clinically, there was ‘no gingivitis’ after brushing practice in 40% of the intervention group whereas, none in control group.

There was a very weak to moderate positive correlation in initial timelines of OPI and GI between control and intervention groups. The correlation after two months period was negative and insignificant.

Conclusion: Though the supervised brushing instruction was given only to intervention group, the plaque accumulation and gingival health rating scores reduced significantly after two months in both intervention and control group. There was a reduction of 0.65 mean OPI score more in the intervention group denoting the true effect of oral health education in intervention group. The supervised tooth-brushing instruction is effective method to improve oral health status among orthodontic patients.

Key words: Charter’s brushing technique, Dental plaque, Gingivitis, Orthodontic patients