Speed of sound measurements in mandibular and phalangeal bone during growth.

The micromechanical and elastic properties of bone, its structural maturity and, indirectly, mineral density are important factors for the planning and assessment of orthodontic and/or jaw orthopaedic treatment. This clinical study was undertaken to evaluate age-related changes in the anterior mandibular body. The speed of sound (SOS) has demonstrated age dependency in various peripheral bones and has been proposed as an alternative method for investigating bone parameters without the use of radiation. The ultrasound transmission velocity was measured in 184 healthy subjects (93 females, 91 males; mean age 17.6 +/- 13.7 years). According to the statistical analysis, the data did not reveal any gender-related differences, but were significantly age-dependent. Different kinetics were established between the maturity of the phalanx and the anterior mandible. Further clinical investigations of age-dependent structural changes in bone maturation parameters may provide information that should be taken into account for early functional jaw orthopaedic treatment.