Sagittal border

The sagittal border (Margo sagittalis), straight and finely denticulate unites to the opposite frontal bone through the interfrontal suture. This junction contributes to form, on the internal surface:

1-in the cranial part, the groove of the dorsal sagittal sinus (Sulcus sinus sagittalis dorsalis) to receive the dorsal sagittal sinus. This sinus is replaced rostrally by the median frontal crest (Crista frontalis) that connects to the crista galli of the ethmoid bone.

2-in the facial part, the septal process (Processus septalis), a more or less irregular and deviated median interosseus plate, enters in the constitution of the septum (Septum sinuum frontalium) that separates the left from the right frontal sinus