By Danielle 
Teenagers who lose teeth due to decay or injury are almost twice as likely to be bullied, according to new Australian research.
The collaborative study by the University of Sydney and the University of Melbourne, published in JDR Clinical & Translational Research, analyzed data from more than 4,400 children in the Longitudinal Study of Australian Children. Researchers followed participants from childhood (ages eight to nine) through adolescence (14 to 15) to investigate the links between oral health and broader health outcomes.
The researchers say tooth loss in adolescence has consequences beyond oral health, influencing mental and social wellbeing.
“Tooth loss isn’t only a dental issue, it’s a social one too,” said senior author Ankur Singh, associate professor and chair of Lifespan Oral Health at the University of Sydney’s School of Dentistry. “For teenagers, it can have significant psychological impacts at a crucial time in their development.”
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The study found that adolescents who had lost teeth were 42 per cent more likely to be bullied compared with peers who had not. About 10 per cent of Australian children are estimated to have lost permanent teeth due to cavities or trauma, with higher rates among those from lower socioeconomic or rural backgrounds.
“Poor oral health affects nutrition, sleep, self-confidence and overall wellbeing, and has also been linked to chronic conditions such as heart disease and high blood pressure,” Singh said. “Governments must invest in prevention programs and improve access to care, especially in low-income and remote communities.”
Yuxi Li, a PhD candidate at the University of Melbourne and first author of the paper, added:
“Anyone who has been bullied knows how awful it can be. Alongside poor mental health, bullying is also linked with physical issues such as overweight and obesity. Our hope is that this research raises awareness about the link between oral health, bullying and young people’s wellbeing.”
Global studies show similar findings
The Australian results align with research from Brazil. A 2024 study of 1,197 students across 37 high schools found that adolescents in schools with frequent bullying had nearly three times as many missing teeth (0.39 vs. 0.14 on average). Even after adjusting for socioeconomic and demographic factors, those students were 2.5 times more likely to have an extra missing tooth compared with peers in schools with less bullying.
Another decade-long cohort study in southern Brazil identified untreated dental decay as a leading predictor of bullying in adolescence.
Earlier research in Jordan, published in 2013 in the American Journal of Orthodontics and Dentofacial Orthopedics, also found that dental and facial appearance were major reasons schoolchildren were targeted by bullies.