What two planes are involved in the occlusal plane angle?

The occlusal plane angle is primarily defined by the relationship between the occlusal plane and the Sella-Nasion (SN) plane. The occlusal plane represents the surface created by the biting surfaces of the teeth, while the SN plane is an important reference line established by the sella (the midline point of the sella turcica in the skull) and the nasion (the point where the frontal and nasal bones meet).

In cephalometric analysis, the occlusal plane angle relative to the SN plane helps to assess the anteroposterior and vertical positioning of the dentition in relation to the cranial base. By measuring this angle, practitioners can gather information on the occlusal relationships, which is crucial for diagnosing and formulating treatment plans for orthodontic and surgical corrections.

Other options involve combinations of different anatomical planes, but they do not directly relate to the occlusal plane angle as specifically or accurately as the SN plane does in conjunction with the occlusal plane. Thus, the relationship between these two planes is essential in cephalometric analysis and orthodontic assessments.