EUROPEAN JOURNAL OF PAEDIATRIC DENTISTRY • 2/2006 67 Dental caries and bone mineral density: a cross sectional study L. FABIANI*, G. MOSCA*, D. GIANNINI*, A.R. GIULIANI*, G. FARELLO**, M.C. MARCI***, E. BALLATORI* ABSTRACT . Aim The relationship between bone mineral density (BMD), age and dental caries has been studied. Quantitative ultrasonography (QUS) is an economic, non invasive, and reproducible method for measuring both bone mineral density and bone elasticity in growing subjects in large populations. Methods This study evaluated the relationship between BMD and prevalence of dental caries (Decayed Missing Filled Tooth - DMFT) in 540 healthy adolescent with mean age 12.3 years, age range 10 to 15 years, resident in two provinces in south Italy. BMD was measured using QUS by calculating the speed of sound (m/s) on the last four fingers of the non dominant hand, with the estimate thus obtained being defined as the AD-SoS (Amplitude-Dependent Speed of Sound and categorised as AD-SoS≤1900m/s and AD-SoS>1900m/s). Occurrence of dental caries was defined using the DMFT index (DMFT=0 and DMFT>0). Results The results of the multifactorial analysis, carried out with logistic model, confirms the expected statistically significant association between response (DMFT) and explicative variables - AD-SoS (P<0.006) and Age (P<0.004). Conclusion Greater bone mineralisation (AD- SoS>1900m/s) and younger age (Age ≤12 years) are dental caries prevention factors: the probability to have caries for the subjects in such conditions is 0,34, about the half of that recorded in the subjects with lower bone mineralisation and older age (0,62). KEYWORDS: Dental caries, DMFT, Bone mineral density, Quantitative Ultrasound, Amplitude-dependent speed of sound, AD-SoS. *Dept. of Public Health and Internal Medicine **Dept. of Experimental Medicine, Paediatric Clinic ***Dept. of Surgical Sciences, Dental Clinic - University of L’Aquila, Italy E-mail: leila.fabiani@cc.univaq.it osteoporosis), traumatic fracture, and dental diseases such as tooth loss and periodontal disease [WHO, 2003]. Other factors such as race, sex, nutrition, health, physical activity and lifestyles all correlate with BMD [Xu et al., 1997]. Regarding oral pathologies mainly the association between BMD and osteoporosis and periodontal disease in elders has been studied, describing related physiopathological mechanisms [Mohammad et al., 2003; Persson et al., 2001; Von Wowern, 2001; Reddy, 2002]. The hypothesis of a a correlation between bone mineralisation and dental caries was rarely, if ever, investigated [Dorozhkin and Epple, 2002; Giannini et al., 2000; Mosca et al., 2000]. Authors agree about the cause of senile osteoporosis [National Osteoporosis Foundation, 2003], with some authors defining it as a "paediatric pathology" [Baroncelli et al., 2003]. There is no scientific evidence correlating dental caries with BMD, however an indirect association can be inferred, whereas Introduction Studies carried out in recent decades demonstrate that bone mineral density (BMD) changes with age, and the diagnostic importance of this variation is now universally recognised [National Osteoporosis Foundation, 1998]. BMD increases from infancy until peak at the age of 18-20. After this age, bone mass in the various skeletal sites stabilises and then progressively declines in both sexes from the third or fourth decade of life, with the decline in women increasing after menopause [Boot, 1997]. Insufficient bone mass during skeletal development in addition to predisposition to senile osteoporosis, is a risk factor for other hard tissue pathologies such as osteopenie (osteomalacia, post-menopausal