• bone mass;
  • jaw;
  • photon absorptiometry;
  • subtraction radiography

The overall aim of this study was to examine the relationship between bone mass of the jaw and the axial skeleton. Sixty-nine subjects (age at entry: 32–64), who underwent hormone replacement therapy during the study period, participated. Bone mass of the lumbar spine was determined using dual photon absorptiometry. The jaw-bone of the posterior region of the mandible was evaluated by means of standardized long-cone radiography using individual bite-blocks. A densitometric wedge in the film holder provided a reference to quantify bone mass. From both measurements, it appeared that the bone mass of the mandible and the lumbar spine showed a moderate relationship. The present results also confirmed that estrogen replacement therapy had a positive effect on the bone mass of the mandible and the lumbar spine. Different estrogen regimens resulted in different increases in bone mass during the observation period, which was on average 5 yr.