Partial or complete division of parietal bones resulting in abnormal cranial sutures is a rare entity and may result in difficulty of differentiation in small children with head trauma.
Usually, non-depressed simple skull fractures are radiolucent, with non-sclerotic borders. In contrast, accessory sutures usually present with sclerotic borders, similar to large skull capillary sutures. The presence of bilaterality in accessory sutures are frequent and are symmetrical especially in the parietal bones. However, skull fractures may also be bilateral but almost always associated with high-impact lesions and therefore often show decreased, marked depression and asymmetry, as well as intracranial lesions, as well as soft tissue injury.
It is important to know the normal anatomy, development and chronology of sutural closure for the evaluation of the small child with head trauma with suspected fracture.
Accessory fractures and sutures can be differentiated in most cases, observing their characteristics, such as bilaterality, symmetry, diastasis, presence of soft tissue injury.