Objective: Ridging along the metopic suture line can be a common cause of concern for parents and has been theorized to represent a mild form of trigonocephaly, a cranial deformity associated with risks of negative cosmetic outcomes, if not surgically corrected. Yet the literature contains sparse reports of long-term cosmetic results or expectations for infants with isolated metopic ridging compared with those with severe trigonocephaly, or even what objective metrics discriminate isolated metopic ridging from severe trigonocephaly. Therefore, the authors' goals for this study were to 1) quantify the degree of frontal deformity among patients with metopic ridge, metopic craniosynostosis, and normocephalic head shapes; and 2) document the natural history of frontal deformities in isolated metopic ridge patients in the 1st year of life.
Methods: This was a retrospective cohort study of patients with normocephalic head shapes, metopic ridges, and metopic craniosynostoses who presented at < 1 year of age to the Connecticut Children's neurosurgery clinic from January 2019 to December 2021. Data were collected regarding demographics and photograph-based craniometrics.
Results: A total of 212 normocephalic, 34 metopic ridge, and 29 metopic craniosynostosis patients were included. Both the normocephalic and metopic ridge groups had a significantly higher anterior arc angle (AAA) value compared with the metopic craniosynostosis group (p < 0.0001). The AAA did not differ significantly among normocephalic patients and those with ridging. Over the course of 1 year of follow-up, patients with metopic ridging demonstrated a slight decrease in AAA values, but overall remained within the same range as normocephalic patients.
Conclusions: Photograph-based craniometrics suggest that metopic ridge patients with frontal bone angulations > 2.2 radians have a mild degree of frontal constriction that does not significantly worsen over the 1st year of life.
Keywords: craniofacial; craniosynostosis; metopic ridge; natural history; trigonocephaly.