Metopic craniosynostosis is commonly characterized by the triad of a keel-shaped forehead (trigonocephaly), biparietal widening, and hypertelorism. Straight lateral frontal bones and narrow orbits with upsloping superior orbital rims are also suggestive of metopic synostosis. Lateral frontal retrusion or pinching can also point to this disorder. Regardless of presentation, there are two approaches to remedying this problem—the more traditional has been open repair and front-orbital advancement and the other an endoscopic strip craniectomy and post-operative helmeting. The latter endoscopic approach is newer and can only be done successfully before 6 months of age since it requires early and rapid brain growth to achieve normocephaly. Which is? Ha et al (10.1542/peds.2020-0238) share with us the results of 31 consecutive non-syndromic infants with isolated metopic craniosynostosis who received open correction or endoscopy. The authors looked at primary anthropometric outcomes in head shape at 5 years after surgery as well as peri-operative factors around the time of the surgery. The study found that endoscopy had a shorter operating time, less blood loss, lower cost, and lower rate of subsequent lateral frontal retrusion. While the authors make a good case for considering endoscopic repair first, they note that the study sample was small and that children >6 months only qualify for the open procedure. The authors make an important point in the discussion section about earlier diagnosis of metopic synostosis and encourage referral for a second opinion from a neurosurgeon even if imaging is not available at the time of referral should the patient be approaching 6 months of age.
This study is a great heads-up on the topic of metopic synostosis and will raise your awareness of the need for earlier suspected diagnosis than perhaps you previously worried about, thinking you had more time to consider this diagnosis if the repair occurred later in the first year of life. Endoscopic repair may become a better option, but the suspicion for this type of craniosynostosis can only happen with a good head exam during an early infancy health maintenance visit. Link to this study and learn more.
