Preoperative craniofacial dysmorphology in isolated sagittal synostosis: a comprehensive anthropometric evaluation

Although clinical descriptions of altered calvarial shape in isolated sagittal synostosis abound in the literature, systematic quantitative assessment of the total morphologic pattern of preoperative craniofacial dysmorphology remains limited in this population. To address this deficit, a retrospective study was undertaken of 256 preoperative patients younger than 6 years with isolated sagittal synostosis who were seen at the Dallas Craniofacial Center. Patients were examined using a battery of 23 anthropometric measurements of the head and face, from which 10 proportion indices were calculated. The measurements and proportions for each patient were compared with sex- and age-matched norms and converted to standard (Z) scores. The pooled data for each variable were analyzed using 1-sample t-tests. The patients were then separated into 2 age groups--younger than 6 months (n = 162) and 6 months or older (n = 94)--and compared via 2-sample t-tests to examine age-related differences. To further elucidate craniofacial growth patterns, standardized anthropometric measures were then correlated against age. Results indicated that the head was enlarged and elongated with compensatory transverse growth of the anterior cranial vault and reduction in the height of vertex. The face was enlarged, especially along the sagittal axis. The head and face were significantly larger relative to age in children younger than 6 months and show a general decrease in size relative to age in all dimensions except cranial length. The data indicate a complex pattern of dysmorphology, which involves the entire craniofacial complex, not just the cranial vault.