A case of an extremely large accessory bone with unusual sutures and foramina parietalia permagna in multiple premature craniosynostoses.

BACKGROUND: Within the entity of craniofacial malformations premature craniosynostoses represent the majority of cases. They originate from disturbances in the ossification process, resulting in an osseous closure of cranial sutures ahead of time. Depending on severity and number of the affected sutures, a local or general growth inhibition of the skull follows. In the rare instance of accessory bones along these affected sutures, they may interfere with diagnostics and therapy.

PATIENT: This clinical report describes the case of a seven-month-old male infant with multiple craniosynostoses, an extraordinary large accessory median calvarial bone, two foramina parietalia permagna and a submucosal cleft palate. Chromosomal and genetic analysis did not reveal potential mutations.

RESULTS: The osseous abnormalities were diagnosed and displayed by three-dimensional computed tomography. The sequential surgical treatment consisted of occipital remodelling at seven months of age and frontoorbital advancement at fourteen months.

CONCLUSION: This rare anatomical variation of the cranial bones - superimposed by multiple premature craniosynostoses - demonstrates the necessity of accurately conducted preoperative diagnostics for appropriate surgical planning. Knowledge, and precise medical examination of potential anatomical variations facilitate the planning and secure performance of surgery as well as its outcome.