Correction of hypotelorism in isolated metopic synostosis.

Surgical correction of trigonocephaly is performed by fronto-orbital reshaping and advancement. Some authors supplement the fronto-orbital remodelling with direct surgical correction of the hypotelorism, but the role of this step of the procedure has been questioned. At Sahlgrenska University Hospital, hypotelorism in metopic synostosis is treated with spring-assisted surgery (S) in children below 6 months of age and with fronto-orbital advancement with the interposition of a bone graft (BG) in the fronto-orbital region at higher age. The aim of the present study was to evaluate the anterior bony interorbital distance (BIOD) preoperatively and at follow-up in patients operated on with the two techniques and to compare the results with adequate control groups. Preoperatively, the patients affected by metopic synostosis had a significantly reduced BIOD compared to their respective controls (S group: 13.8 ± 1.6 (mean ± SD) mm vs 18.6 ± 1.4 mm, p < 0.001, BG group: 14.7 ± 1.0 mm vs 18.8 ± 1.4 mm, p < 0.001). At 3 years follow-up, BIOD was improved in both groups, but only in the S group the mean BIOD did not differ from the control group (19.7 ± 2.9 mm vs 20.2 mm ± 1.3 mm, p = 0.3). In the BG group the BIOD was still significantly different between patients and controls (17.6 ± 1.8 vs 20.0 ± 1.1 mm, p < 0.001). Spring-assisted surgery performed before 6 months of age can normalise hypotelorism in metopic synostosis. Full correction in a large series of patients has now been achieved for the first time.