Severe Plagiocephaly Due to Isolated Left Frontosphenoidal Craniosynostosis: An Exceptional Presentation.

Craniosynostosis is a condition characterized by premature fusion of cranial sutures, leading to abnormal head shapes and potential developmental and neurological complications. Although craniosynostosis typically involves major cranial sutures, isolated frontosphenoidal suture fusion represents an exceptionally rare entity. In this case report, we present a 2-year-old girl with a rare occurrence of early closure of the left frontosphenoidal suture, resulting in significant left-sided plagiocephaly. After frontal-orbital advancement surgery with barrel-stave osteotomies, the patient experienced remarkable improvement in cranial symmetry, confirmed by follow-up CT imaging 3 months postsurgery. This case establishes isolated frontosphenoidal synostosis as a novel cause of anterior plagiocephaly, necessitating inclusion in standard diagnostic protocols for cranial asymmetry evaluation. Early surgical intervention provides excellent functional and aesthetic outcomes.