Sex-related Differences in Cortical and Trabecular Bone Quantities at the Mandibular Molar

Uncertainty exists regarding sex-, age- and tooth-related cortical and trabecular bone quantity tendencies at the mandibular first molar, a frequent implant recipient site in partially edentulous patients with missing molars. We assessed these tendencies for the mandibular first molar by using computed tomography in patients missing the first molar on one side. Eighty-two subjects were assessed. Cortical and trabecular bones were quantified using computed tomography image reformatting software on a cross-sectional image, including the site of the mandibular first molars on sides with and without the first molar. Bone quantity associations with age and between the sides with and without the first molar were evaluated. Bone quantities were compared according to sex and between the two sides. Great interindividual variations between cortical and trabecular bone quantities were seen in both sexes and on the two sides. Although no sex-related or age-related difference in trabecular bone quantity existed, men demonstrated a greater cortical bone quantity than women; women, but not men, exhibited an age-related decline in cortical bone quantity. Bilateral symmetry of both bone quantities appeared only in women. Cortical bone quantity did not differ between the two sides in either sex, while trabecular bone quantity differed; the side without the first molar had greater values than that with it in women and, to a lesser extent, in men. A computed tomography analysis distinctively measured cortical and trabecular bone quantities and unveiled their sex-related differences in a clinical situation, as specifically designed in this study.