Isolated Frontosphenoidal Synostosis: Early Clinical Management of a Rare Condition With Distraction Osteogenesis

Isolated frontosphenoidal synostosis (FSS) is an extremely rare pathology in which premature fusion of the frontal and sphenoid bones produces asymmetry of the forehead in a newborn or young child. If left untreated, these children may suffer significant esthetic and neurologic symptoms. Therefore, surgery is time-sensitive and necessary for correction. This report details the case of a male infant who presented to clinic at 3 months of age with unilateral, isolated FSS. Clinical features of this patient included an asymmetric forehead with flattening of the right frontal temporal area, indentation of the right temporal sphenoid area, and inferiorly displaced right orbit. Previous reports have been in older patients who were treated with open fronto-orbital advancement. With the patient's early presentation, the primary surgical approach deployed here included anterior cranial vault remodeling with right distractor placement and fronto-orbital osteotomy. Four months following the procedure, the patient returned with increased right-sided hypoglobus and enophthalmos. CT imaging revealed a pseudomeningocele, secondary to a dural tear. Consequently, the 7-month-old underwent a second surgery, which included fronto-orbital advancement reconstruction. The child remains stable with improved forehead symmetry at 11 months of age. Due to the rare nature of FSS, treatment options are limited and traditional in their approach. This report aims to contribute additional clinical insights and treatment guidance to the growing body of literature surrounding FSS.