ANTERIOR ENCEPHALOCELE

Always occur in the midline sagittal axis of the cranium. They occur at sites of fontanelles (frontal and sphenoidal), or at the cribriform plate of the ethmoid, the foramen caecum or magnum or through a sutural line.

Two main groups:

• Sincipital (external lesions that occur near the nasal root, the glabella and are subdivided into nasofrontal, nasoethmoidal and nasoorbital).
• Basal defects (internal lesions that occur within the nose, pharynx or orbit and are subdivided into spenoorbital, spenomaxillary, transethmoidal, spenoethmoidal and spenopharyngeal).