The association between the masseter muscle, the mandibular alveolar bone mass and thickness in dentate women.

OBJECTIVE

Since muscle strength has been demonstrated to affect the bone in the long bones and spine, the possibility exists that the bone mass and dimension of the alveolar processes could be influenced by the function of the masticatory muscles. Therefore, the purpose of this study was to investigate whether two local factors (ultrasonographic masseter thickness, and occluding teeth) plus the skeletal bone mineral density (BMD) affect the mandibular alveolar bone mass (MABM) and the bucco-lingual alveolar thickness of the alveolar process.

DESIGN

The thickness of the masseter muscle was evaluated by ultrasound imaging in 62 dentate women (40-75 years) with no periodontal disease and no dental infection in the premolar region consecutively selected from the patients in a public dental clinic. MABM was evaluated using periapical radiographs. The bucco-lingual thickness of the alveolar process was measured on dental casts with a dial calliper. BMD of the forearm was determined with dual energy X-ray absorptiometry.

RESULTS

Multiple regression analyses demonstrated that masseter thickness and the number of occluding mandibular teeth in the lateral segment were significant determinants of MABM and of the interdental thickness, but BMD was not. The number of years after menopause and struma/gastro-intestinal disease influenced MABM but not the alveolar thickness.

CONCLUSION

The local factors played an important role in the posterior mandibular segment and their effect might partly explain the low correlation between MABM and skeletal BMD.