Prospective anthropometric analysis of sagittal orbital-globe relationshipfollowing fronto-orbital advancement in childhood

Fronto-orbital advancement is a common procedure for correction of supraorb ital retrusion in patients with coronal craniosynostosis. The aim of this s tudy was two-fold: to quantitate change in the sagittal orbital-globe relat ionship following fronto-orbital advancement in childhood and to determine the ratio of skeletal-to-soft tissue movement. Soft-tissue points on the orbital rim, orbitale superius (os), orbitale lat erale (ol), orbitale inferius (oi), and nasion (n) referenced to apex corne ae (ac), were measured preoperatively and postoperatively by a custom-made anthropometer. Intraoperative bony advancement was measured with a caliper. Patients were selected with uniform advancement at the fronto-nasal suture and laterally at the mortise and tenon. Fifteen patients with syndromic cr aniosynostosis were included in the study (six male, nine female): Apert (n = 2), Crouzon (n = 5), Pfeiffer(n = 4), Saethre-Chotzen (n = 3), and Bosto n type (n = 1). Average age at operation was 8.7 years (range, 4.5 to 10.5 years). Age, sex, method of fixation, postoperative interval, diagnosis, an d skeletal movement were analyzed for possible effect on the magnitude of s oft-tissue advancemet. Average intraoperative skeletal advancement was 12.1 mm: and average postop erative soft-tissue movement was 10.3 mm (p < 0.001), measured at the midpo int of the supraorbital rims (os). The soft tissue: skeletal movement ratio was 0.9:1. Os was the only point at which soft-tissue advancement could be predicted (Spearman's rank correlation coefficient = 0.67); soft-tissue ch anges at ol, oi, and n were unpredictable. Skeletal movement was the only d eterminant of soft-tissue advancement of all variables tested, i.e., diagno sis, age, sex, previous fronto-orbital advancement, and wire versus plate f ixation. We make recommendations for calculating the magnitude of fronto-orbital adv ancement, based on preoperative anthropometry and a soft-to-hard tissue adv ancement factor.