Measurement of the midface symmetry in trauma and reconstructive surgery.

The pre- and intraoperative determination of the midface symmetry during the management of trauma or reconstructive surgery cases may be difficult due to swelling of the covering tissue. To handle these problems, a new apparatus, called "Zygometer", is introduced. This instrument is able to measure the position of the midface bones and enables a comparison with the controlateral side. The results of a study with 250 persons to get standard measurements for symmetry and asymmetry are presented and discussed. Indications and clinical application of the zygometer are demonstrated.