Analysis and treatment of severe trigonocephaly.

A retrospective analysis of seven patients with clinically severe trigonocephaly was performed, including a review of preoperative and postoperative computed tomography scans. A method of analyzing the trigonocephalic deformity was developed. This is based on determination of the angular severity of the forehead (110 +/- 4 degrees) and the length of half of the supraorbital bar (40 +/- 3 mm). This central angle was found to be relatively constant in this population. Using simple trigonometric relationships, a rationale for the alternative method of reconstruction used in these patients is presented. This technique is based on transverse expansion of the supraorbital bar, transposition of the lateral orbital rim, expansion of the temporal fossa, and recontouring the orbital aperture. As a separate consideration and step, the bony interorbital distance is widened.