Association between number of teeth present and mandibular cortical erosion in Japanese men and women aged 40 years and older: A cross-sectional study

Mandibular cortical bone structure as risk indicator in fractured and non-fractured 80-year-old men and women

Objective

To investigate the association between mandibular cortex parameters and fracture in a group of 286 men and women, 79–80 years of age.

Study design

In a cross-sectional study, the mandibular cortex was evaluated with Klemetti’s index for cortical erosion. The cortical thickness was measured with a ruler adjusting for the magnification factor. The odds ratio (OR) for fracture when having a severely eroded cortex or a cortex thickness < 3 mm was calculated.

Results

A normal cortex was found in 65% of men, whereas only 7% had a severely eroded cortex. The OR for severely eroded cortex  as fracture risk predictor was significant (2.32; 95% CI 1.3–4.2), also when the female group was evaluated separately. A significant difference was found between the mean thickness for men (3.96 mm) and women (2.92 mm), respectively. The OR for cortical thickness < 3 mm was significant (2.00; 95% CI 1.1–3.6) in the total group, but not when men and women were evaluated separately.

Conclusions

Among old women, the cortical parameters were significantly associated with prevalent fracture. In old men, other circumstances may be more important.