Gnathion (Gn) is primarily associated with which measurement in cephalometric analysis?

Gnathion (Gn) is a key anatomical landmark in cephalometric analysis, defined as the midpoint between the Gonion (Go) and Menton (Me) of the mandible. Its primary relevance lies in measuring the anterior-posterior position of the mandible relative to the maxilla. This measurement is crucial in assessing potential discrepancies between the dental and skeletal relationships, which can inform treatment planning in orthodontics and orthognathic surgery.

When considering the options, the anterior-posterior position is directly influenced by the position of Gnathion since it reflects how far forward or backward the mandible is placed in relation to the maxilla. This is pivotal for establishing a proper occlusal relationship between the upper and lower teeth.

The other aspects, such as vertical dimension, facial symmetry, and occlusal plane orientation, involve different measurements and landmarks. While they may relate to overall facial analysis, they do not specifically pertain to the function of Gnathion in measuring the anterior-posterior position, which is why it is recognized as the most relevant measurement in this context.