Which line is used to determine skeletal issues in cephalometric analysis?

The S-N line, which connects the Sella and Nasion points, is commonly utilized in cephalometric analysis to assess skeletal relationships and to identify skeletal discrepancies. This line serves as a reliable reference for various measurements, particularly in understanding the spatial orientation of the maxilla and mandible in relation to the cranium.

By using the S-N line, practitioners can evaluate the anteroposterior position of the jaws, as well as assess vertical relationships, which are crucial for diagnosing skeletal issues such as class II or class III patterns in orthodontics. The significance of the S-N line lies in its role as a fixed anatomical reference point, as it remains relatively constant among different individuals, thus providing a consistent basis for comparisons across cephalometric analyses.

In contrast, the other options—such as the anterior-posterior line, Menton line, and Nasion line—while important for specific assessments in cephalometrics, do not primarily serve the function of determining skeletal issues as directly and effectively as the S-N line does.