Study Links Anterior Crossbite to Tooth Loss

A recent observational study conducted by researchers from Tohoku University has identified an association between anterior crossbite, a type of malocclusion, and a higher prevalence of tooth loss in adults aged 40 years and older.

The study found a link between anterior crossbite and a higher prevalence of tooth loss in adults, particularly those aged 40 and above.

Malocclusions, often described as misaligned bites, occur when upper and lower teeth do not properly align when the mouth is closed. Previous research has linked specific malocclusions to tooth loss, with conditions like crossbite and open bite potentially altering the force distribution on teeth during chewing.

Methodology

The research team analyzed data from 17,349 adults aged 40 and above from the Tohoku Medical Megabank Project Community-Based Cohort Study. Participants were categorized into four groups based on detailed oral measurements:

• Normal occlusion
• Anterior open bite
• Anterior crossbite
• Combined malocclusion

Researchers assessed the prevalence of having 19 or fewer remaining teeth and posterior tooth loss to evaluate the effects of anterior crossbite and open bite compared to a normal bite.

Key Findings

The study revealed several significant associations:

• Adults with an anterior crossbite showed a higher likelihood of tooth loss and a 1.14-fold increased risk of losing molars.
• This association remained significant after adjusting for critical factors such as age, sex, oral hygiene practices, presence of caries, periodontal disease, and lifestyle choices.
• The differences in molar retention between the occlusal groups were more pronounced in older age groups, highlighting age-related vulnerability.
• In contrast, adults with an anterior open bite demonstrated a lower prevalence of posterior tooth loss, suggesting varying impacts of different anterior malocclusions on overall tooth retention.

Kento Numazaki, assistant professor at Tohoku University, highlighted the broader public health implications of these findings.

"Identifying this risk is important given that having fewer than 20 teeth can affect chewing, nutrition, frailty, and healthy life expectancy."

Future Research

The research team plans to conduct longitudinal studies to further understand how tooth loss progresses in individuals with anterior crossbite over time. They also aim to explore whether these associations observed in Japan are consistent in other populations globally, potentially through international collaborations.