Mobile-health Intervention to Promote Oral Health in Adolescents: A Cluster Randomized Controlled Trial

Health Belief Model and Family-based Mobile-health Intervention to Promote Oral Health in Adolescents: A Cluster Randomized Controlled Trial

The aim of this study is to investigate the effectiveness of the family and behavioral theory based mobile-health behavioral intervention in enhancing adolescents'good oral health behaviors (mainly oral hygiene practice and free sugar intake control) and preventing common oral diseases (dental caries and periodontal diseases).

The investigators propose a 30-months clustered randomized controlled trial to investigate the effectiveness of Health Belief Model (HBM) and family-based mobile-health intervention in enhancing the adolescents' good oral health behaviors and preventing oral diseases.

This is a three-arm parallel-design cluster-randomized controlled trial. Parents and their children (12 to 15-year-old) will be recruited and randomized into 3 groups based on the school sites.

Messages targeted on six domains guided by HBM will be sent to the adolescents and their parents via mobile phone. Two blocks of HBM-based oral health messages, reminders, feedback and reinforcement messages will be delivered to both students and parents by mobile phone for 24 weeks; while the intervention of the other 2 groups will target on students only or using prevailing oral health education.

The primary outcomes will be caries increment of the adolescents 2-year post-intervention. Change in oral health self-efficacy and behaviors, dental plaque and gingival bleeding index will be the secondary outcomes.

The investigators anticipate the proposed family- and HBM-based behavioral intervention is more effective than HBM-based mobile-health intervention on adolescents alone or prevailing oral health education in improving the adolescents' oral hygiene behaviors, reducing free-sugar intake and preventing oral diseases.

Inclusion Criteria:

• Chinese ethnicity;
• Student living with their own parent(s) or primary caregivers;
• Both student and parent(s) or primary caregiver having their own access to a personal mobile phone with certain Apps to receive the messages in time

Exclusion Criteria:

• Student currently on a special diet (e.g. severe inflammatory bowel disease);
• Student has medical conditions know to affect growth or eating (e.g. diabetes, cystic fibrosis);
• Enrollment in other oral health promotion programs or research studies.