Comparing two fronto-orbital advancement strategies to treat trigonocephaly in metopic synostosis.

BACKGROUND

Trigonocephalic treatment entails frontoorbital reshaping of the forehead, increasing bitemporal dimensions, and advancing lateral orbits. Various techniques can achieve this, but no consensus exists regarding effects on long-term skull growth. Overcorrecting forehead dimensions is one strategy though preserving a vascularized fronto-orbital bar can influence future growth. We therefore seek to craniomorphologically compare fronto-orbital advancement (FOA), using bandeau widening and advancement, to a pedicled "tilt" procedure to assess whether adequate 3D remodeling is achieved.

METHODS

Demographic and computed tomographic data was recorded. Pre- and post-craniometric measurements were performed for the endocranial bifrontal angle, orbital plane angle, anterior advancement and the interzygomaticofrontal suture distance.

RESULTS

40 CT scans were analyzed, with similar demographics. No perioperative complications were encountered. The endocranial bifrontal angle increased in the FOA (p = 0.00026) and tilt groups (p = 0.00297), along with the orbital plane angles (FOA, p = 0.020498; tilt, p = 0.07371), the anterior advancement (FOA, p = 0.00932; tilt, p = 0.05823), and the interzygomaticofrontal suture distance (FOA, p = 0.001241; tilt, p = 0.07811).

CONCLUSIONS

Both techniques improve frontoorbital dimensions for correction of metopic synostosis. In severe trigonocephaly phenotypes, the FOA allows a greater magnitude of expansion and overcorrection, but compromises preservation of a vascularized leash. The "tilt" procedure possesses the benefit of near-anatomic bandeau remodeling, while potentially improving long-term growth.