NaSiOnO

Nasiono is the Polish term for the anatomical landmark internationally known as nasion. It is a standard cranial reference point used in anatomy, physical anthropology, and dental and orthodontic sciences. The nasion denotes the point at the frontonasal suture where the frontal bone meets the two nasal bones, typically defined as the midline or deepest point of that suture in the midsagittal plane.

As a cephalometric landmark, nasion serves as a datum for measurements on radiographs and 3D skull models. Common measurements and constructs that use nasion as a reference include the S-N vertical plane (Sella to Nasion) and various facial angle assessments. The precise localization of nasion can vary slightly among individuals and with imaging technique, but it remains a standard, stable reference in growth studies and orthodontic planning.

In anatomy and anthropology texts, nasion is described as a midline point rather than a bone itself. It is used to describe craniofacial morphology and to relate facial structures to the skull base. Its role as a reference point makes it central to comparative studies of skulls across populations and to clinical assessments of facial development.

See also: cephalometry, cranial sutures, frontal bone, nasal bones, skull.