Factors associated with poor oral hygiene by intraoral region among residents with disabilities in Thai residential facilities: a cross-sectional secondary analysis

OBJECTIVES: To estimate the prevalence of poor oral hygiene using the Simplified Oral Hygiene Index (OHI-S) overall and by intraoral region and to identify factors associated with poor oral hygiene among residents with disabilities in Thai residential facilities. MATERIALS AND METHODS: We conducted a secondary analysis of a facility-based cross-sectional oral health survey conducted in two government-run residential facilities in Thailand. Poor oral hygiene was defined as OHI-S 3.1-6.0 (versus 0-3.0) and evaluated for anterior teeth, upper posterior teeth, lower posterior teeth, and overall (six index teeth). Associations between participant characteristics/behaviors and poor OHI-S were examined using chi-square tests. Multivariable logistic regression models were fitted for each intraoral region and overall OHI-S, including a priori selected predictors based on conceptual relevance to oral hygiene in disability and residential-care settings, availability in the dataset, and model parsimony. RESULTS: The analytical sample included 298 participants. Poor oral hygiene was most prevalent in the upper posterior (63.0%) and lower posterior regions (57.7%); overall poor OHI-S occurred in 55.7%, and poor anterior OHI-S in 37.4%. In adjusted analyses, adults aged 19 to 59 years had higher odds of poor overall OHI-S (adjusted odds ratio [aOR] 3.19, 95% CI 1.59 to 6.40). Physical disability was associated with poor anterior OHI-S (aOR 3.77, 95% CI 1.32 to 10.73). Brushing fewer than twice daily was associated with poor upper posterior OHI-S (aOR 2.90, 95% CI 1.21 to 6.91), poor lower posterior OHI-S (aOR 2.69, 95% CI 1.20 to 6.05), and poor overall OHI-S (aOR 2.19, 95% CI 1.02 to 4.70). Chewing problems were associated with poor anterior OHI-S (aOR 3.11, 95% CI 1.20 to 8.06). CONCLUSIONS: Poor oral hygiene was highly prevalent among residents with disabilities, particularly on posterior teeth. These findings suggest prioritizing daily plaque control support, with targeted attention to adults aged 19-59 years, residents who brush less than twice daily, and those with functional limitations such as chewing difficulties.