Background: The authors compared cranial growth across three patterns of fronto-orbital remodeling for metopic synostosis.
Methods: The authors reviewed all patients who underwent fronto-orbital remodeling for isolated metopic synostosis between 2006 and 2009. Inclusion criteria consisted of patients with preoperative, short-term postoperative (4 to 12 months), and long-term postoperative (>36 months) three-dimensional photographs. Patients were categorized by fronto-orbital remodeling pattern: group 1, retrocoronal; group 2, partial coronal; and group 3, precoronal. Head circumference, minimum frontal breadth (ft-ft), and maximum cranial length were measured by three-dimensional photographs, converted to standard Z scores, and compared.
Results: Thirty-one patients met inclusion criteria (group 1, n=12; group 2, n=10; and group 3, n=9). Group 1 presented with the greatest phenotypic severity. From preoperative to short-term postoperative assessment, head circumference Z scores rose for group 1 but dropped for groups 2 and 3, and the three groups demonstrated equivalent increases in minimum frontal breadth Z scores. From short-term to long-term postoperatively, the three groups demonstrated similar stability in head circumference Z scores but decreased minimum frontal breadth Z scores. From preoperatively to long-term postoperatively, head circumference Z scores rose for group 1 but fell for groups 2 and 3 (change in Z score, 0.5, -0.5, and -0.7, respectively; p=0.06) and the three groups demonstrated equivalent drops in minimum frontal breadth Z scores. Across preoperative to short-term postoperative and preoperative to long-term postoperative assessment, group 1 displayed the least drop in maximum cranial length Z scores.
Conclusions: Retrocoronal patterns of fronto-orbital remodeling provide long-term gains in head circumference percentile and the least growth impairment in cranial length. Irrespective of osteotomy design, expansion in frontal breadth relapses significantly over time.
Clinical question/level of evidence: Therapeutic, III.